Characterizing Hope: An Interdisciplinary Overview of the Characteristics of Hope

What we hope for has a large impact on how we feel and behave. Research on the determinants and effects of a hopeful disposition is increasing in several academic fields, such as psychology, nursing and organizational studies. However, how hope is defined differs significantly between disciplines, leading to fragmentation in the insights that we can draw from this research. This systematic review aims to provide an extensive overview of the ascribed characteristics of the concept of hope in ten different academic fields. Using phenomenographic research methods, these characterizations are collected and categorized to offer a comprehensive conceptual framework of hope. The resulting framework comprises 7 themes and 41 sub-themes. We show how this framework can be used to obtain a fuller understanding of the concept of hope and of possible blind spots within specific research fields.


Introduction
Subjective experiences are increasingly recognized within academia and policy as important drivers of individual behaviour and societal change. This has resulted in a burgeoning literature on subjective experiences, such as emotions, in the social sciences and humanities, as insights into the affective dimension of human life can clarify many hitherto unexplained, 'irrational' behaviours (Bruni & Sugden, 2007;Kahneman, 2013;Webb, 2007;Schwartz, 2010;De Waal, 2019). Hope is one such experience that has appeared to be a very relevant incentive for human behaviour, and the concept has received increased attention over the past decades from varying disciplines, such as positive psychology, nursing, environmental studies, anthropology and organizational studies (Kleist & Jansen, 2016;Luthans & Jensen, 2002;Snyder, 2000a;Webb, 2007). Hope can entice people to invest in their future, for example through a business, an education, in living healthily, accepting treatment for a disease, or in collaborating with others in solving societal problems (Snyder, 2000a;Duflo, 2012;Elliot, 2007;Lybbert & Wydick, 2015;Ojala, 2012). Such a hopeful motivation for behaviour requires belief in and the imagination of a certain good or desire. Additionally, it is based on a belief in someone's capabilities to achieve this goal or trust in the abilities of others to do so, such as societal institutes, government, science or a God or deity. As a form of imagination, hope can allow people to transcend their current situation and, as such, battle apathy and provide a 'renewed zest for life' in times of hardship, such as during sickness, poverty or societal injustice (Benzein & Saveman, 1998;Ludema et al., 1997;Schwartz & Post, 2002).
Despite an increased recognition of the importance of hope in understanding behaviour, there seems to be no sufficiently comprehensive overlapping definition or framework of the concept that is applicable across disciplines (Webb, 2007). Some succinct definitions seem to be valid across approaches, such as what is called the 'orthodox definition' of hope, i.e., a desire for a possible but uncertain goal. This definition thus entails two necessary and sufficient components of hope: desire and uncertainty (Day, 1969;Martin, 2011). Few, if any, scholars concerned with hope would have issue with the claim that hope at least involves a desire for something and some form of uncertainty. However, such a description is so brief that it does not capture the much more detailed and elaborate descriptions used within different disciplines and consequently offers little help in linking research across disciplines. Therefore, research on hope within, for example, anthropology, has little or no connection to research on hope within psychology, apart from the very abstract definitional 'core' represented by the orthodox definition, which has little descriptive power. As such, research on hope is largely performed within the confines of different disciplines or 'clusters of meaning'.
Consequently, definitions and characterizations of hope can differ widely, from 'an affirmative form of social discourse' (Ludema, Wilmot & Srivastva, 1997), to 'the anticipation of achieving a personally significant future good' (Leung et al., 2009), 'an emotion network' (Scioli et al., 2011), a cognitive process involving agency and pathways to goals (Snyder, 2000a), 'an emotion that occurs when an individual is focused on an important positive future outcome' (Bruiniks & Malle, 2005), positive psychological capital (Luthans & Jensen, 2002), or 'an inner power directed toward a new awareness and enrichment of "being"' (Herth, 1993). Although often divergent and sometimes even contradictory, it is likely that most of these definitions of hope have some truth to them. Different dimensions of hope can be elicited in different situations, and since scientific disciplines each have their own scope and focus, all come up with different interpretations of the concept. As Webb (2007: 80) states, different contexts can elucidate different 'modes of hoping': We may each of us at different times and in different circumstances experience hope in the manner described by Marcel or Dauenhauer or Bloch or Snyder or Rorty. Our hopes may be active or passive, patient or critical, private or collective, grounded in the evidence or resolute in spite of it, socially conservative or socially transformative. We all hope, but we experience this most human of all mental feelings in a variety of modes.
Almost all approaches to defining hope regard it as a multifaceted concept but focus mainly or solely on one or a few 'modes of hoping'. Since interdisciplinary meta-analyses of the concept are scarce, we rarely see how these different modes are connected. This hinders research on the role of hope in context since we know little about the interplay between different characteristics of a hopeful feeling. This paper aims to contribute to the research field by providing an overview of the central characteristics of hope from an interdisciplinary perspective. Building on Webb's (2007) description of hope as 'a human universal that can be experienced in different modes', we aim to disentangle the building blocks that make up these different modes of hoping. This will not only help to understand the meaning and role of hope in real-life contexts but also to put mono-disciplinary approaches in a broader context. Knowledge of different perspectives on the characteristics of hope can result in better and more useful research in the future, as it helps researchers to not simplify unnecessarily or overlook important characteristics in the context of their research. This means that these insights could also help to develop more relevant correlational and causational models between hope and other states or circumstances. For example, understanding the social characteristics of hope could inform researchers focused on a more individualistic perspective, common in fields such as psychology or economics, of the importance to consider the relation between social capital or societal hierarchy and hope, a topic which might otherwise be overlooked. Moreover, a more inclusive understanding of the characteristics of hope could inform the development of more comprehensive and valid psychometric instruments, or motivate researchers to use multiple instruments to cover a wider array of characteristics of hope. Also, a broader understanding of hope could help practitioners to better understand the role hope plays in their work field, meaning that they can make more informed choices about, for example, how to improve the conditions or quality of life of the people they work with.
Using a systematic phenomenographic review of articles on hope within several disciplines, such as economics, environmental studies, health science, history, humanities and social sciences, we aim to offer a comprehensive interdisciplinary framework that can be easily used to disentangle what components a specific approach or definition is focusing on.
The paper is structured as follows. The second section gives a short overview of the current state of affairs, asking which characteristics are regarded as being central to hope in current influential theories, how our understanding of hope has changed over time and what topics are under debate. The third section discusses the methodology of the phenomenographic analysis of this study. The results are discussed in section four, where we will show how two general approaches to defining hope can be used to structure an interdisciplinary 'classification matrix' of the characteristics 1 3 of hope. Moreover, we discuss seven domains and several subthemes related to the characteristics of hope. Section five starts with a recap of the complete classification-matrix and uses it to elucidate some of the differences between disciplines in studying hope. Section six offers a discussion of the results and some limitations.

Theory
Hope is certainly not a new topic of research. It has been studied within several disciplines throughout history. However, until the twentieth century, hope was usually merely considered as a 'secondary' part of a larger philosophical or academic project. Only after this period did structured and empirical investigations specifically focused on hope itself became more prevalent (Bloeser & Stahl, 2017;Webb, 2007).

Hope Throughout History
Over time, hope has had many different connotations and has been portrayed as both good and evil. Early Greek accounts of hope focus mostly on the latter by equating hope to wishful thinking based largely on ignorance that keeps people from courageously facing reality (Bloeser & Stahl, 2017;Ludema, Wilmot & Srivastva, 1997). Although several Greek thinkers such as Aristotle and Plato also recognize the motivating power of hope and the possibility of courageous hope, by and large, hope was seen as irrational, generally naïve, easily used for the wrong goals, and sometimes overly eager, while at other times, it was seen as a cause for apathy (Gravlee, 2020). In contrast, Judeo-Christian interpretations of hope actually ascribe a virtuous character to hope since it can motivate behaviour in the absence of direct, rational evidence, instead relying on faith in the possibility of good. 1 During the seventeenth and eighteenth centuries, thinkers of the Enlightenment mostly defined hope as a neutral passion, which can motivate both rational and irrational behaviour. Although also comprising cognitive beliefs about reality and the probability of attaining one's goals, descriptions of hope focused on its emotional characteristics. In addition, hope was increasingly seen as a political power by thinkers such as Hobbes and Spinoza, since it can motivate people towards societal progress and solidarity through, for example, laws and the social contract (Boukala & Dimitrakopoulou, 2017;Bloeser & Stahl, 2017). In philosophical discussions since Enlightenment, hope is again portrayed as both good and evil. Immanuel Kant describes reasonable hope as a rational imperative, seeing it as a bridge between reason and existential questions that cannot be answered by experience (Insole, 2016;Bloeser & Stahl, 2017). Authors such as Kierkengaard and Marcel similarly discuss hope as transcending the limitations of (empirical) understanding and as an inherently human trait pulling people towards progress. Thinkers such as Schopenhauer and Nietzsche, on the other hand, condemn hope as a misguided understanding of reality that mostly distracts people from addressing injustice. Nietzsche went so far as to label hope 'the greatest of all evils for it lengthens the ordeal of man ' (1996: 32). With the rise of psychoanalysis at the beginning of the twentieth century, attention again swayed to the more positive side of hope as an expression of fundamental trust in others and a basic force of human psychology (Ludema, Wilmot & Srivastva, 1997). Similarly, pragmatic philosophers such as Dewey and Rorty regard hope and trust in the goodness of others as a rational choice even in the absence of proof, since it offers the energy to work towards progress and improvement (Ludema, Wilmot & Srivastva, 1997;Webb, 2013). Here, the societal impact of hope again comes into play, as hope is seen as a potential force for social transformation. Political thinkers such as Bloch elucidate the pivotal role that hope can play in societal progress due to its potential to spark the imagination of possible new futures, which can help challenge the status quo (Ludema, Wilmot & Srivastva, 1997;Mandel, 2002;Nullens et al., 2016). In the second half of the twentieth century, hope as a research topic gained popularity, especially within the fields of psychology and nursing, where the focus shifted to the cognitive, emotional and behavioural components, determinants and effects of hope.

Current Theories
In recent decades, a large body of empirical research has developed on the causes and effects of hope, for example, with regard to performance and wellbeing. Since these studies largely focus on the application of existing theories rather than definitional clarification, they largely build upon existing theories. Consequently, a handful of theories have become very influential in hope research. Perhaps the most well-known theory comes from psychologist Snyder, who defines hope as 'a positive motivational state that is based on an interactively derived sense of successful (a) agency (goal-directed energy) and (b) pathways (planning to meet goals) ' (2000b: 8). To Snyder, hope is predominantly an individual and cognitive experience. Although he recognizes that other people can be a source of hope, Snyder defines the experience itself as individualistic. Moreover, even though he sees emotions as an important part of the hoping process, Snyder regards them as secondary to cognitive processes and therefore as less central. Based on this theory, Snyder has developed several instruments that are widely used for research on hope (Snyder, 2000a). Nonetheless, there has also been substantial criticism on this theory, for example, for being too individualistic (Du, 2015), for focusing too much on personal control and agency and too little on trust (Tennen et al., 2002), for not sufficiently differentiating hope from optimism (Aspinwall & Leaf, 2002), for dismissing the role of emotion and for deviating substantially from how people experience hope in daily life (Tong et al., 2010). Another theory that has been influential in many other studies comes from Herth, a professor in nursing studies (1992). She defines hope as 'a multidimensional dynamic life-force characterized by a confident yet uncertain expectation of achieving good, which to the hoping person, is realistically possible and personally significant' (Herth, 1992(Herth, : 1253. The tool based on this theory, the Herth Hope Index, focuses on expectations, a positive feeling about the future and the social context of hope and is specifically designed to measure hope among patients during periods of illness. Furthermore, the Beck Hopelessness Scale developed by psychiatrist Beck (1974) has been used extensively within several academic fields and defines the absence of hope as 'a system of negative expectancies concerning [ourselves] and [our] future' (Beck et al., 1974: 861). One last instrument that has gained importance over the past years is the Values in Action Inventory of Strengths, based on the work of Peterson and Seligman. Here, hope is mainly defined as positive psychological capital that helps people to transcend difficult circumstances. The measuring instrument developed to study hope in this context is very similar to those developed by Snyder (Peterson et al., 2007).

Existing Meta-studies
The increasing number of theories and studies on hope have motivated several researchers to perform meta-analyses or reviews of hope research. A large proportion of these reviews focuses on research within health sciences. For example, Hammer and others (2008) investigate several studies on the experience of hope among sick and healthy people, yielding metaphors of hope such as specific hope, hope seen as a light on the horizon and hope seen as weathering a storm. Focusing on the experience of hope among family caregivers of persons with a chronic illness, Duggleby and others (2010) offer a conceptual framework with the following four themes: transitional refocusing from a difficult present to a positive future, dynamic possibilities within uncertainty, pathways of hope, and hope outcomes. Schrank and others (2008) conduct a similar meta-analysis on the definition and effects of hope within psychiatry and categorize the 49 definitions they find in the following seven dimensions: time, an undesirable starting point, goals, likelihood of success, locus of control, relations, and personal characteristics. Several studies have also been conducted within the field of psychology. For example, Alarcon and others (2013) analyse research on hope and optimism and show that the two are related but distinct concepts if they are measured empirically. Reichard and others (2013) systematically review studies on the effects of hope at work and indicate several positive work-outcomes related to hope. Within the field of anthropology, Kleist and Jansen (2016) identify two trends in the literature on hope: 'an emphasis on hopefulness against all odds and one on specific formations of hope and temporal reasoning'. Although there are several meta-analyses within the confines of a discipline, relatively few focus on multiple disciplines. One notable expectation is a study by Webb (2007), which attempts to disentangle the myriad of competing conceptions of hope from the twentieth century. Webb describes how different conceptions of hope can come to the forefront of different 'modes of hoping', including patient hope, critical hope, estimative hope, resolute hope and utopian hope.

The Standard Account of Hope
Thus far, we have seen that there are many divergent approaches to defining hope. Several 'core elements', however, seem to be recurrent and can therefore be taken as a starting point in defining hope. The orthodox definition (Martin, 2011) or standard account (Meirav, 2009) of hope states that there are two dimensions to hope: a desire combined with a belief about the possibility of attaining this desire (Day, 1969). According to this definition, the expected probability of attaining what one hopes for should range between what we believe to be highly improbable to highly likely but cannot contain something that is logically impossible or certain to happen. 2 Although most, if not all, theories of hope would agree that the orthodox definition offers two necessary conditions for hope, it is much more questionable whether they are also sufficient to describe what hope is. Certainly, when considering the complex experience of hope, the standard account seems to be quite scant. Although it fits within virtually all theories, it also leaves out many elaborations, nuances and discussions, for example, whether hope is experienced individually or socially, whether hope feels positive or negative, whether the object of hope should be important or not, whether hope focuses on a specific goal or is a more general feeling, whether hope is focused on the immediate future or not, whether hope is active or passive, or whether hope mainly manifests as emotion, cognition or behaviour.

The Current Study
Adopting the premise put forth by Webb (2007) that hope can be experienced in different modes and that different (and sometimes even contradictory) characteristics of a hopeful state will be experienced in different contexts, this study aims to offer an overview of these characteristics and how they are related, without assuming that one characterization is necessarily better than another. We assume that all descriptions of hope that are at least somewhat prevalent within at least one scientific discipline have relevance to them and should therefore be considered when giving an overview of the central domains of hope from an interdisciplinary perspective. Even if not all characteristics of hope are obvious in each and every context or study, it is important for those interested in the topic to be aware of perspectives besides of their own. This method will not only help to develop a broader understanding through an awareness of the differences and similarities between perspectives but will also help to position the specific approach adopted relative to others.

Methods
To analyse how hope is characterized in different disciplines, a phenomenographic approach is adopted. Phenomenography is a relatively new research method that aims to explore different ways of experiencing or understanding a particular phenomenon (Åkerlind, 2005). This approach differs from the more well-known approach of phenomenology 3 in its focus; while phenomenology focuses on "the structure and meaning of a phenomenon", phenomenography focuses on "the different ways a group of people understand a phenomenon" (Larsson & Holmström, 2007). So, the aim of the phenomenographic approach used in this research is to investigate how different scientific disciplines understand a phenomenon like hope and what characteristics they ascribe to it. Phenomenography is based on a nondualistic ontology that assumes that a phenomenon neither exists solely as an objective, universal concept in the outside world nor is solely constructed by people's interpretations in specific contexts. Rather, the phenomenographic approach assumes that a phenomenon is constituted by the relation between the object and different experiences of that object. Thus, although each experience of hope is different from another, these interpretations are related through the commonality in the object. As such, a phenomenon such as hope can be represented by different but logically related categories of description coming from different perspectives. The aim of phenomenography is to offer not only a set of different interpretations but also a 'logically inclusive structure relating the different meanings', by analysing how interpretations are related to each other (Åkerlind, 2005: 323). The approach is particularly appropriate in this study because it can elucidate the characteristics attributed to hope in different disciplines and offer an overview of how these different perspectives are related.

Data Selection
To provide a rich, interdisciplinary overview of perspectives, the sources for this study were checked according to eligibility criteria in four stages. 4 First, in the Web of Science Core collection, all articles that had the term 'hope' listed as an author keyword were selected, which yielded 1,936 documents. 5 Subsequently, the twenty most-cited articles within the fields of economics and business studies, environmental studies, health studies, history, humanities, philosophy, political science, psychology, social science, theology and youth studies were chosen. 6 These fields were selected because they included many articles on hope, offered diversity in perspectives and were expected to be most relevant concerning the topic. To account for the fact that older publications have had more time to be cited, we differentiated between sources published before and after 2013, selecting the ten most cited sources from both periods. This yielded 649 articles in total 78 . Then, articles were selected if they had a substantial focus on the concept of hope, were scientifically rigorous, and did not solely make use of existing instruments without adding any new interpretation to the theories they were derived from (i.e., the Adult Trait Hope Scale (Snyder et al., 1991), the Values In Action Inventory of Strengths (Peterson & Seligman, 2004), the Herth Hope Index (Herth, 1992), the Beck Hopelessness Scale (Beck et al., 1974), and the Goal Specific Hope Scale (Feldman et al., 2009)). A substantial focus on hope means that articles were excluded if hope was only mentioned a few times or if the article focused on a different type of hope, such as 'the Cape of Good Hope' or the 'the HOPE housing project'. Scientifically rigorous means that opinion articles without references, bachelor's and master's theses and articles that were not peer-reviewed were excluded. The reason for excluding articles that solely used existing scales is that these articles would not offer substantial new perspectives in addition to the seminal theories on which they are based, which were already included in the analyses (Beck, 1975;Herth, 1992;Snyder, 2002). This process of exclusion yielded a total of 259 articles. At this stage, none of the articles from the field of history could be retained; therefore, this discipline was dropped from the analysis, and ten disciplines remained. Last, the most relevant articles were selected based on the scope of the article and the relevance of the topic (i.e., the characteristics of hope). Here, scope means that the articles that covered more information, such as reviews or meta-analyses, were prioritized. Articles with a very specific population or location were excluded, since this analysis aimed to cover relatively broadly adopted perspectives of hope, i.e. the most common within the respective mono-disciplinary fields, and a focus on such specific context was deemed outside of the scope of this overview. Relevant topics were considered those that focused explicitly on the definition or characteristics of hope. Altogether, 66 articles on the topic of hope from ten different disciplines were included in the overview 9 . Of these articles, 4 are from the field of economics and business, 7 are from environmental studies, 12 are from health science, 3 are from humanities, 8 are from philosophy, 5 are from political science, 10 are from psychology, 8 are from social sciences, 3 are from theology, 3 are from youth studies and 3 are the seminal studies by Beck (1975) Herth (1992 and Snyder (2002). No other search engines in addition to the Web of Science core collection were used to find possible eligible studies from additional sources. The aim of this step in the study was not to offer an exhaustive overview of all possible sources on hope within each of the ten disciplines, but to find a sufficiently diverse range of key sources within the disciplines to get a thorough understanding of the most common approaches to hope across these different scientific disciplines (Table 1).
Despite including 66 articles on hope in this analysis, potentially important and insightful documents might have been overlooked. However, in addition to the unfeasibility of analysing all articles, books and other outlets ever written on hope, the selection of articles for this study was not designed to be exhaustive within disciplines but to incorporate a sufficient diversity of perspectives across disciplines to offer a reasonably representative interdisciplinary overview.

Data Management and Analysis
The initial analysis was performed using Atlas.ti (8.2.32.0) (2018), a workbench for the qualitative analysis of large bodies of textual data. Using this program, all parts of the texts were noted that offered either a definition of hope, descriptions of the characteristics of the concept, or clear assumptions about the author's interpretation of the definition or characteristics of hope. These quotes were all described with several central themes. After an initial trial round of coding using ten randomly chosen articles, the first coding themes were established 10 . Subsequently, all articles were analysed using the same themes. In total, 1,814 pieces of text were coded. Any citations that did not match an existing theme were coded as 'other'. After the first round of analyses was completed, all citations coded as 'other' were again analysed and assigned to new themes if the same theme was mentioned in at least three separate documents. Out of 322 quotes labelled as 'other', 68 could not be matched to a sufficient number of similar quotes to create a new theme. These quotes were therefore not included in the analysis. Overall, 1,746 quotes describing characteristics of hope were labelled with one or more themes in Atlas.ti. This allowed us to: group descriptions into categories, based on similarities and differences (Larsson & Holmström, 2007); collect and compare all quotes covering a certain theme; calculate and compare how common different themes are; and to assess which themes are most  (Beck, 1975;Herth, 1992;Snyder, 2002) 256 259 4 Substantial scope Meta-analyses and reviews prioritized Articles with a very specific population or location excluded Relevant topic Articles with a focus on the definition or characteristics of hope prioritized 66 10 All coding themes are available upon request from the first author. common in each source or scientific discipline (Table 2) 11 . As such, we were able to discern different perspectives on the characteristics of hope across the ten disciplines and how these perspectives relate to each other.

Reliability
Up to this point, all analyses were performed by one researcher. To assess the reliability of the analyses, two checks were performed. First, two researchers, who had not seen or read the articles before, defined themes for lists of five quotes that were deemed to be related to one theme by the first researcher. No major differences arose between these themes. Any minor differences were discussed, and if necessary, adjustments were made to the theme description. Second, the second and third researchers were offered a list of quotes from five articles and asked to assign themes to these quotes. In 69% of the cases, at least one of the themes assigned to a quote overlapped between researchers, whereas in only 14% of the cases, multiple themes overlapped. Although this may seem a relatively low amount of overlap, we should keep in mind that at this point, 28 different themes were used to label sometimes very complex pieces of text. Moreover, discussion between researchers showed that most, if not all, discrepancies followed from a different focus within the text, rather than disagreement about the content of the text. Furthermore, since these themes were used to describe one concept, they naturally shared some overlap. Even though the themes appeared not to reflect all topics discussed perfectly, the topics that were coded were reflected accurately by the themes. Additionally, the labelling of quotes was not aimed at perfectly or exhaustively reflecting all themes present in the text but at offering a wide variety of common interpretations of hope and the themes that bind these interpretations. For these reasons, we would say that the coding reflected the different themes in these texts relatively well.

Synthesis
To analyse how different characteristics and experiences of hope are related, the 43 themes were listed and then clustered according to shared meaning and combined in an initial scheme by the first researcher. This scheme was evaluated by two other researchers by trying to correctly identify where they thought all themes should fit within the scheme. This discussion led to some adjustments. Several new schemes were proposed and discussed until a consensus was reached about the best way to portray the general relations between the clusters of description. To do so, several new subcategories were created within the themes, and others were combined or somewhat revised. Subsequently, the quotes related to the themes within a cluster were reread to come to a thorough description of each cluster. Finally, all the themes within the clusters were re-evaluated and combined or further categorized if necessary until only several central themes remained within each cluster. The complete classification matrix contains 7 clusters, 39 themes and 6 subthemes and will be discussed in detail in paragraph 5.1.

Results
The results of this study are based on extensive literature but can be presented in a relatively simple classification matrix, which will be discussed in its entirety in Sect. 5. In this section, we will explain step-by-step how this matrix is constructed.

Two Approaches
A first and overarching categorization that can be made regarding the literature on hope is based on a differentiation between two approaches: one is understanding hope as an individual experience and the other is understanding it as a comprehensive context-dependent process. The first approach aims to offer a concise definition of what a person is experiencing when she is hopeful and describes only the most necessary characteristics of this experience. The second approach is based on the assumption that hope is a process without a clear start or end, which is inherently tied to its (social) context. Therefore, the followers of this approach assume that to understand what hope is, we also need to know what gave rise to it, what its objective is, how it affects us, and in which context it exists. These two approaches are not mutually exclusive, and many thinkers offer a theory of hope that is a combination of the two. However, in defining the characteristics of hope, the distinction is valuable, especially since these perspectives can lead to quite different conclusions; for example, when discussing whether hope is individual or social, active or passive, and virtuous or not, while followers of the first approach will state that related issues to hope, such as trust or action tendencies, are not truly part of the hoping experience and should therefore not be taken into consideration, the followers of the second approach would consider these issues as being fundamental to our understanding of what hope truly means to us.

The First Approach: Hope as an Individual Experience
Since the first approach to defining hope is interested in isolating the most essential characteristics of the individual experience of hope, these theories usually look for the smallest amount of necessary and sufficient building blocks. Although perspectives vary, most centre on the themes of desire, an estimate of the probability of attaining this desire and a response to the uncertainty in attaining what we want 12 .

Desire
Although hoping can be distinguished from wishing, a wish or desire is usually considered as a prerequisite for hope (Day, 1969;Eaves et al., 2014). This desire can be either positively or negatively formulated, i.e., as something that we want to achieve or a currently negative situation that we want to leave (Webb, 2010). Imagining possible futures and the mental act of anticipating desired outcomes are important characteristics in this respect and are often taken understood to distinguish hope from simple wishing (Drahos, 2004;Eaves et al., 2014). Hope is about creating a narrative, a plot that makes sense of our developments by creating a link between our current situation and the future (Smith & Sparkes, 2005). This 'active desiring' is a creative process that allows us to envision alternative futures, set goals and brace for possible negative outcomes (Ludema, Wilmot & Srivastva, 1997;Elliot, 2007). Hope is about choosing to focus on the possible good that might happen, despite uncertainties (Kadlac, 2015;Stevenson & Peterson, 2016;Hornsey & Fielding, 2016). Imagination allows us to explore possible future developments and to place our desires within a broader context of possibilities 13 .

Probability Estimate
Although most, if not all, descriptions of hope include an estimation of the probability of attaining one's desires, there are quite contradictory ideas about how these probability estimates function, i.e., whether a hoped-for goal should be perceived as being likely or unlikely to happen. On the one hand, there are theories that state that hope is likely to arise when expectations are positive (Schwartz & Post, 2002;Schrank, Stanghellini & Slade, 2008;Hobbs, 2013). In this case, it is assumed that realism differentiates hope from mere wishing or optimism and that hope should be focused on achievable goals (Benzein & Saveman, 1998;Bland & Darlington, 2002;Weingarten, 2010;Edera, 2015). Here, it can be stressed that unrealistic or false hopes are at best useless and at worst dangerous since they increase the likelihood of disappointment and distress when hopes are not realized, and they are easy to take advantage of (Wiles, Cott & Gibson, 2008, Webb, 2010. Moreover, it can be assumed that positive expectations should lead to a higher 'goal commitment', whereas unrealistic hopes will be more passive 14 (Hornsey & Fielding, 2016). On the other hand, some theories posit that hope actually flourishes when it is 'against all odds' (Kadlac, 2015;Kleist & Jansen, 2016). People can be quite unrealistic in their hopes, sometimes even deliberately, because this helps them to deal with reality, for example, during illness or other misfortune (Benzein, Norberg & Saveman, 2001;Eaves et al., 2014). It could even be assumed that hope is a logical consequence of relatively low expectations, since it 'arises in situations where we understand our own agency to be limited with respect to the things or conditions that we desire. If our own agencies were not so limited, we would not hope for what we desire; we would simply plan or act so as to achieve it' (McGeer, 2004). Moreover, some theories posit that hope should be against all evidence, as hope can be a transformative power in cases where outlooks on the future are grim, for example, in repressive or unjust societal contexts (Drahos, 2004;Webb, 2010). However, most theories seem to agree that hoping for something that is (virtually) certain (not) to happen does not make sense.

Experiencing Uncertainty
Since hope is inherently about things that we cannot predict, dealing with uncertainty is an important component of many theories of hope (Webb, 2007;Ojala, 2012;Kadlac, 2015). This means that hope is not about mere wishing or wanting but about choosing to focus on the possibility of attaining one's desire while acknowledging that it might not happen (Kadlac, 2015). Following this line of thought, expressing hope becomes a way of expressing awareness of this uncertainty; that is, saying that you hope for an event implies that you realize it might not happen (Elliot, 2007). Several theories centre on the idea that cultivating constructive hope is about finding the 'right' balance between belief in desired possibilities and an understanding of the chance of failure (Schrank, 2002;Cantor, 2006;Elliot, 2007;Leung et al., 2009). Such a balance should allow individuals to be motivated to pursue their goals while remaining realistic enough to overcome disappointment and resist manipulation by others (Snyder, 2000a;Eaves, Nichter & Ritenbaugh, 2016;Kleist & Jansen, 2016;McCormick, 2017). At times when uncertainty plays a large role in the hoping experience, hope appears to become much more process-focused. For example, when hope transcends our current understanding of reality, i.e. when we hope for some kind of positive future without knowing exactly how this future will look, it requires a fundamental openness to the future (Webb, 2010). Quite often, this means that the hoper experiences that being in the process of moving towards some kind of positive state makes sense and has meaning in and of itself, even if they do not know the exact goal (Webb, 2007;Eaves et al., 2014). Taking such a stance grants a certain flexibility to hoping, since it means that disappointment on one specific goal does not imply that hope is lost completely. Rather, hope can focus on new goals that fit within a larger project or on finding new meaning within the current situation (Hammer, Mogensen & Hall, 2009;Eaves et al., 2014). It is only when one loses a sense of openness to the future, when no possibilities seem to exist at all, that one comes to despair (Antelius, 2007).

Layers of Hope: Emotion, Cognition and Behaviour
Most theories state that hope is a multidimensional concept, comprised of, for example, emotional, cognitive, motivational, social and identity-related components (Snyder, 2000a(Snyder, , 2000bFolkman 2010;Ojala, 2012;Webb, 2013). The existence of such a 'multi-layered' hopeful experience could explain why it is possible in some instances to maintain hope on one level while simultaneously experiencing decreasing hope or even despair on another level or to have contradictory hopes (Weingarten, 2010;Eaves et al., 2014;Jansen, 2016). For example, even when hearing bad news about the chances of attaining one's goals and while fully understanding how this affects us, we might still feel hopeful. In practice, different degrees and expressions of these components of hope can generate quite various and very specific types of hope 15 (Kleist & Jansen, 2016). Considering this diversity of ways in which hope can be experienced, some thinkers question whether hope is truly one experience or whether it is actually a complex 'syndrome' or a collection of thoughts, feelings, actions and expressions (Ojala, 2012, Eaves, Nichter & Ritenbaugh, 2016. However, there is little agreement about which components exactly make up the 'hopeful syndrome'. Here, we consider the three components that are, by far, mentioned most often, namely, cognition, emotion and motivation. Cognition is an important part of many theories of hope. Mentioned often in this regard is that hope comprises an assessment of the future and our chances of attaining our desires (Drahos, 2004;Kadlac, 2015;Luthans & Youssef, 2007;Snyder, 2000aSnyder, , 2000b. Here, hope is regarded as the mental act of anticipating and imagining a future situation and as such serves as a psychological resource, as it helps us prepare for and address changes in our lives (Luthans, 1997;Drahos, 2004;Webb, 2010). Moreover, it can be stressed that hope usually does not come and go without our conscious deliberation. Contrary to strong physiological emotions such as fear, which can be processed rather unconsciously, it could be said that hope virtually always requires at least some conscious cognitive activity, such as creativity and flexibility in dealing with the information at hand (Bar-Tal, 2001). Additionally, the cognitive component of hope surfaces in its problem-solving focus. Hope is at least partly about constructive thinking, i.e., taking in information and actively using it to achieve our goals (Ojala, 2012). It is therefore perhaps not surprising that strongly cognitive hopes are often seen as being more realistic than mostly emotional ones (Hobbs, 2013).
However, there are also several arguments to be made that indicate that hope is mostly an emotion. First, some writers stress that thoughts about achieving a desired goal are merely sources of hope and not part of hope itself. According to them, hope is about the positive emotion that accompanies these thoughts (Boukala & Dimitrakopoulou, 2017;Hornsey & Fielding, 2016). Others do not preclude hopeful thoughts as part of the experience but do state that the way in which hope is usually expressed indicates that the emotional component is much more important (Leung et al., 2009). These writers, for example, stress that hope can be hard to control, has a feeling tone, involves appraisal and often motivates behaviour, which are all characteristics of emotion (Cohen-Chen et al., 2014;Poels & Dewitte, 2008;Scioli et al., 2011). Moreover, it is sometimes stressed that hope cannot be purely or even mainly cognitive, since it often covers issues that cannot be fully known and require a great deal of faith in things that stretch beyond the strictly rational (Ludema, Wilmot & Srivastva, 1997).
Another component of hope that is often mentioned is its motivational force. Some thinkers state that hope is fundamentally active, since it involves thinking about possible pathways to achieving one's goals and how to sustain this action (Snyder, 2000a(Snyder, , 2000bSchwartz & Post, 2002;Stevenson & Peterson, 2016;Kleist & Jansen, 2016). Others stress that hope can and sometimes even should be quite passive. The things we hope for are uncertain and not always within our control, so it is sometimes wiser to adopt a stance of humility and wait and see (Halpin, 2001;Braithwaite, 2004;Edera, 2015). However, most theories are somewhere in between; they state that although hope is not necessarily active, it does imply a 'readiness' to act (Benzein & Saveman, 1998;Webb, 2007;Poels & Dewitte, 2008;Pechenino, 2015). Hope indicates that 'our interests, our concerns, our desires, our passions-all of these continue to be engaged by what can be; hence, we lean into the future ready to act when actions can do some good' (McGeer, 2004). This motivational force is especially apparent when it helps people to persevere in difficult circumstances or in the absence of certainties (Smith & Sparkes, 2005;Zigon, 2009;Ojala, 2012;Reichard et al., 2013;Webb, 2013;Hornsey & Fielding, 2016).
Therefore, it is quite plausible that the 'hopeful syndrome' entails at least cognitive, emotional and motivational components. Moreover, there are several other components that are perhaps not always present but can still be important in understanding some expressions of hope. For example, hope can have a strong spiritual component, can be a virtuous act, and can be about mastery or social interaction (Ludema, Wilmot & Srivastva, 1997;Hammer, Mogensen & Hall, 2009;Scioli et al., 2011;Ojala, 2012;Kadlac, 2015;Griggs & Walker, 2016). There is probably no way to definitely determine which components of our experience truly are part of hope, but it seems plausible that it is never just one of these. Thus, hope is the complete process of interwoven moments of thinking and feeling, or a 'unifying and grounding force of human agency' (Drahos, 2004;McGeer, 2004;Webb, 2010).

The Second Approach: Hope as a Context-Dependent Process
While the first overarching approach to defining hope puts much effort in delineating what is and is not hope, the second approach seems to be based on the idea that it is practically impossible to pinpoint where hope starts and ends since it is a process without a clear beginning or end, and because it is inherently tied to its social context. The aim of this approach is to understand which parts of the context and process of hope fundamentally alter its meaning.

Hope as a Process
Similar to general emotion in appraisal theories, hope can be perceived as a process, i.e., as an episode involving several changing components, such as appraisal, motivation, physiological responses, behaviour and feelings. Moreover, each such change can provide feedback to the other components (Moors et al., 2013). As such, hope becomes a cyclical process; how we evaluate our circumstances might affect how we feel, which in turn can spark motivation, which again changes how we perceive our situation. Rather than an emotional state, which is relatively static, defining hope as a process means that what hope entails changes over time, that the experience of hope can influence itself, and that it is therefore very difficult to mark a start and end to it (Elliot & Olver, 2007).
In the literature on hope, we do indeed find several mentions of the cyclical character of the experience. For example, when followed over time, people report decreases and increases in different dimensions of hope. Since hope involves a process of the 'appraisal of possible outcomes, cognitive analysis for maintaining and achieving hopes, and goal pursuit' (Leung et al., 2009), we constantly adjust our hopes to our perceived chances of success (Luthans & Youssef, 2007). This is especially apparent among patients with long-term illnesses such as cancer or chronic pain; here, hope can change from being wishful, small and utopian to realistic, large and practical in a relatively short time frame, based on experiences, expectations and the possibility of a cure (Benzein, Norberg & Saveman, 2001;Eaves et al., 2014;Eaves, Nichter & Ritenbaugh, 2016). Additionally, hope depends on the amount of time that people have had to assess and cope with their situation (Folkman, 2010;Wiles, Cott & Gibson, 2008) and on the amount of time that people have had to better understand their own desires (Kadlac, 2015). Especially during difficult times, people can intentionally maintain hopes that they know are unrealistic because they need something to hold on to. Given enough time, such wishful hoping can transform into accepting reality, if people can come to terms with it or if they start to get attached to different, more attainable hopes (Eaves et al., 2014). Moreover, what we hope for is strongly influenced by the stories or narratives people construct about themselves, their surroundings and their hopes (Antelius, 2007). Similarly, such developments can occur on a social or societal level. The stories we tell about our (shared) history can instil discontent about our current situation and a shared longing for a better future. Politicians, for example, often use these types of narratives to spark societal change by appealing to shared hopes (Bar-Tal, 2001;Duggleby et al., 2010;Cohen-Chen et al., 2014;Kleist & Jansen, 2016). As such, our constantly changing history influences how we perceive ourselves and what we hope for (Esteves et al., 2013;Hammer, Mogensen & Hall, 2009).

Hope in Context
Although hope can often be a highly personal experience centred around personal responsibility and convictions about the world and our chances of attaining what we want (Drahos, 2004;Hammer, Mogensen & Hall, 2009;McGeer, 2004;Snyder, 2000a), hope literature also often discusses the impact of our direct social surroundings, such as friends and family, but also more distant influences, such as institutional, political, cultural and economic contexts. Such social contexts appear to play a role in different parts of the hope process. Other contexts can be a source of hope, for example, by teaching us to be hopeful, by helping us achieve our goals, or by ensuring a sense of meaning, trust and self-worth (Benzein & Saveman, 1998;Elliot, 2007;Du & King, 2013). Our sense of hope can have many effects on others, for example, in giving others hope or comfort (Ludema, Wilmot & Srivastva, 1997;Boukala & Dimitrakopoulou, 2017). However, we can also experience shared hopes when goals are shared and people engage with these hopes together (Weingarten, 2010;Torres & Tayne, 2017). Moreover, when asked about their hopes, a substantial portion of people report that others, or their relation to others, are the object of their hopes (Bland & Darlington, 2002;Howell et al., 2015).
Nonetheless, hope is often not regarded as a purely 'social emotion', in the sense that its primary function is not always to serve a social function (Hareli & Parkinson, 2008). However, the reason the social dimension is often deemed to be so important in understanding what hope is seems to lie in the understanding that the process we go through is inherently connected to others; others influence what we deem possible, desirable, how we define ourselves and our future, and therefore how we hope. This indicates that, even if hope itself might often be experienced individually, we would have only a limited understanding of hope if we were to disregard this social context completely.

The Classification Matrix
How do we synthesize the idea that hope can encompass a broad, context-dependent process, while some theories choose to focus on the individual experience? In our classification matrix, we assume that the process of hope, i.e., the development of different components of a hopeful experience, and the context of hope, i.e., the individual or internal and social or external developments, make up two axes along which we can classify different characteristics of hopeful experiences.
First, regarding the process component, we differentiate between the sources of hope, the experience of hope and the effects of hope. The distinction between these stages is not always completely clear-cut; as discussed previously, there are many relations and feedback loops between these phases, leading to border cases and cross-categories. However, here, we try to make a distinction between the experience of hope itself on one side and the events that cause hope to develop and the effects that hope have on the other. We include these sources and effects because we assume that they fundamentally affect how we understand the hope process that they become part of.
Second, we divide the social-context component into external and internal processes of hope. While the internal component here refers only to the individual 16 , the external component is much more comprehensive; it comprises a wide range of contexts such as friends and family, society at large, politics, culture, etcetera 17 . The reason for combining these contexts into one category is that, on top of the unfeasibility of creating different categories for each context we live in, these external processes often share important commonalities compared to individual experiences, in 16 In this article, we refer to this category as either internal, individual or personal. Although these terms have slightly different connotations, we use them to refer to the same category. 17 Similarly, in this article, we refer to this category as external, social or shared hope. that they are usually less within our control, cannot always be fully comprehended, can be much more abstract, and to a greater degree, require trust in some unknown.
We combine these two categorizations since the different stages of the hoping process take place in all types of social contexts and, conversely, different social contexts go through several stages of the hoping process. Together, this results in both internal and external sources of hope, internal and external experiences of hope, and internal and external effects of hope. We therefore take the individual experience of hope, which is the main focus of the first approach to defining hope, to be one part of this classification matrix, since it relates only to one moment in the hoping process and one social context (see Fig. 1).
Last, one important component of hope falls outside of these descriptions, namely, the object of hope, i.e., what we hope for 18 . Since this object lies outside the experience of the hoper themselves, it does not lend itself to be analysed as a lived experience and is therefore placed outside of the axes. However, since it is often regarded as fundamentally affecting how we can define hope, it is still included in the classification matrix. (1) and hope as a context-dependent process (2) 18 Although the experience of hope itself entails desire (as will be discussed in more detail in paragraph 4.3.1), we differentiate between the feeling of desire and the object of that desire as something that can be analysed by itself.

In Detail: Sources and Effects of Hope and Social Experience
Thus far, we have discussed the two overarching approaches to defining hope. On the one hand, there are theories that try to discern hope's most central elements, and on the other hand, there are theories that treat hope as a broad, contextualized process. One approach is not necessarily better than the other, but if we take the second approach seriously, then solely focusing on the individual experience of hope at all times would limit our understanding. Here, we will therefore further focus on the elements of hope that follow from defining hope as a context-dependent process, i.e., internal and external sources, external experience, and internal and external effects. We will give several examples of these categories and cover the themes that are discussed most often in the literature on hope, but we do not aim to be exhaustive; there are many possible sources, experiences and effects of hope. However, we aim to discuss only those components that fundamentally alter what it means to hope.

Internal Sources
Under the category 'internal sources' of hope, we gather all feelings, traits and circumstances that take place within and originate from an individual's personal experience that can cause someone to be hopeful or increase the strength of their hope.
First, several theories state that hope is an inherent, biological human tendency, since humans are always searching for improvements to their circumstances (McGeer, 2004;Webb, 2010;Scioli et al., 2011). Dissatisfaction plays an important role in this regard, as it signifies that things are not (yet) how we want them to be, leading to action or at least hope for change (Webb, 2010). Nonetheless, it seems that this innate tendency to hope can be thwarted, especially when previous experiences have led to (repeated) disillusionments, thereby making people less prone to be hopeful (Edara, 2015). Experiencing repeated success, on the other hand, can encourage hope (Ojala, 2012;Pecchenino, 2015).
Since hope is about achieving possible but not certain events, assumptions about our own abilities are very important. Indeed, several writers state that confidence, self-worth and personal control are important, perhaps even necessary, for developing hope (Folkman, 2010;Krause & Hayward, 2015;Pechenino, 2015). Moreover, other personal traits can influence how likely a person is to be hopeful. What is deemed possible to achieve, for example, depends on personal characteristics, such as age, gender, health, disability, etc. (Leung et al., 2009;Pecchenino, 2015). Also mentioned particularly often in this regard is one's personality, specifically traits such as courage, humility, modesty, serenity, security, humour, malleability belief (i.e., the belief that reality can be influenced) and locus of control (i.e., the belief that we have personal control over our environment) (Benzein & Saveman, 1998;Vilaythong et al., 2003;Webb, 2010;Du & King, 2013;Cohen-Chen et al., 2014;Kadlac, 2015).
Although some writers state that hope can be sparked by temporary positive emotions or mood (Bland & Darlington, 2002), others stress that hope is a complex and at least partially cognitive phenomenon, meaning that hope requires creative, conscious and rational thinking (Ludema, Wilmot & Srivastva, 1997;Bar-Tal, 2001;Weingarten, 2010;Cohen-Chen et al., 2014) and that hope therefore can be a deliberate choice, i.e., choosing to focus on the possibility of a positive outcome rather than that of a negative outcome (Bland & Darlington, 2002;Weingarten, 2010). Hoping itself can be considered a virtuous act if people choose to 'equip' themselves with it as a resource to keep them pursuing what is right, even in the presence of uncertainties and disappointment (Zigon, 2009;Weingarten, 2010;Insole, 2015) (Fig. 2).

External Sources
External sources of hope can encompass all types of events, circumstances and influences that exist outside of an individual. This domain can thus refer either to a close friend or family member, a work environment, societal institutes, a god or a worldwide development such as globalization or climate change. Here, we discuss some components that are mentioned particularly often in the literature.
Our direct social circle can be very important in determining our hopes, for example, by teaching us to and 'infecting' us with hope, especially during childhood (Schwartz & Post, 2002;Snyder, 2000a;Webb, 2013), by providing a constructive and safe environment in which hope can develop (Benzein & Saveman, 1998;Leung et al., 2009;McGeer, 2004;Schwartz & Post, 2002) and by providing feedback on how we are functioning and how worthwhile our hopes are (Eaves et al., 2014;Ludema, Wilmot & Srivastva, 1997;Pecchenino, 2015). It is therefore perhaps not surprising that education is often mentioned as an important source of hope. During youth, we can learn that our agency may be limited but that it is still worthwhile to pursue what we deem to be valuable (McGeer, 2004;Webb, 2007;Kerret, Orkibi & Ronen, 2016). Moreover, similar to having trust in ourselves, hope can originate from trust in others and their abilities to help us achieve our hopes, as this trust offers support, safety and confidence, even in times of disillusionment or lack of personal control (Ludema, Wilmot & Srivastva, 1997;Stevenson & Peterson,  Culture also plays an important role in this regard, as hope is valued differently in varying cultures and children thus learn different ideas about the importance of hope (Smith & Sparkes, 2005). For example, in Catholic contexts, maintaining hope is considered very important, sometimes even more important than conveying a sad (but real) truth (Toscani & Maestroni, 2006). In Asian cultures, hope is often about what is attainable or reasonable rather than what is ideal (Wang, Joy & Sherry, 2013). Western cultures, on the other hand, seem to value optimism and hope a great deal by making hopeful expressions very infectious and sometimes even somewhat mandatory (Eaves, Nichter & Ritenbaugh, 2016).
Furthermore, well-functioning societal institutes such as judicial systems, police forces, national governments or scientific institutes can be important prerequisites for developing as well as maintaining hope, as they offer the required safety and societal structure to live a good life and attain personal and societal progress (Braithwaite, 2004;Drahos, 2004;Stevenson & Peterson, 2016). History plays an important role in this regard. Experiencing repeated disappointment of hopes, for example, during intractable conflict, can create apathy, hopelessness and distrust (Cohen-Chen et al., 2014). Moreover, this is also a matter of politics, since hope is usually not equally distributed in society, i.e., some groups, such as minorities or disadvantaged groups, are offered less hope by their surroundings (Kleist & Jansen, 2016). At the same time, poverty or deprivation means that solutions that claim to offer hope are in great demand (Drahos, 2004).
Additionally, as work is an important part of most people's lives, the organizations we work in can greatly impact the hopes that we experience. By offering opportunities to grow and uphold a corporate culture of fairness, employees are Fig. 3 External sources of hope in the classification matrix more likely to develop hopes for themselves and the company at large, which will in turn affect their performance (Reichard et al., 2013;Schwartz & Post, 2002).
Especially in cases where the answer to one's hopes cannot easily be found in either oneself or in one's direct or indirect environment, a personal faith system can become an important source of hope (Eaves, Nichter & Ritenbaugh, 2016). Such a faith can be but does not need to be religious (Scioli et al., 2011). Rather, such faith is about having 'affective, normative, spiritual, and relational resources that are typically excluded from the process of knowing' and therefore creating a deep trust that things might work out well in the future without requiring direct proof (Ludema, Wilmot & Srivastva, 1997;Bland & Darlington, 2002;Toscani & Maestroni, 2006) (Fig. 3).

Social Experience of Hope
When individual hopes are shared by a number of people, often in response to societal or political developments, they can become a 'public ', 'social' or 'shared' hope (Bar-Tal, 2001;Drahos, 2004;Atwater, 2007;Elliot & Olver, 2007;Weingarten, 2010;Kleist & Jansen, 2016). Such social hopes often rely on the same components as the individual experience of hope, i.e., desire, a probability estimate and uncertainty, although there are also some differences.
First, shared desire, which is based on collective visions and imaginations of what makes a meaningful and dignified life, can arise within a small group of people, such as a family, but can also arise at a societal level when a shared (national) history of images, ideals, values and 'ultimate concerns' affect how we think about life and progress (Kleist & Jansen, 2016;Ludema, Wilmot & Srivastva, 1997). For example, metanarratives, which cover recurring themes in political, philosophical, cultural discussions, can greatly influence what large groups of people strive for. This is illustrated by modernist metanarratives of the twentieth century, which attached great value to progress, agency and control over our own lives. This way of thinking greatly influenced how we now think about hope for wealth, health and wellbeing, i.e., things that are within our control as long as we put our minds to them (Snyder, 2002;Antelius, 2007;Kleist & Jansen, 2016;Singh, 2016;Smith & Sparkes, 2005). Second, a shared probability estimate is an important component of the social experience of hope. We can only hope for the things we assume to be possible, which in turn largely depends on societal expectations and assumptions (Benzein & Saveman, 1998;Pecchenino, 2015). Since these ideas can be highly 'infectious', they can become a shared sense of pessimism or optimism and thus become the core of social hope (Bar-Tal, 2001;Schwartz & Post, 2002). Moreover, in regard to societal issues such as climate change, hope can be displayed by placing trust in societal institutes and technical and scientific developments (Ojala, 2012;Eaves et al., 2014;Stevenson & Peterson, 2016). Conversely, societal institutes such as the state can also distribute hope unequally among different groups of people due to the different opportunities that are offered to them (Schwartz & Post, 2002;Kleist & Jansen, 2016). As such, marginalized groups can structurally experience less hope than other groups. Third, because social hope depends upon the behaviour and solidarity of others, uncertainty and trust are specifically important.
The role of uncertainty is twofold; on the one hand, uncertainty can create suspicion and anxiety, while on the other hand, uncertainty can also be the main driver of hope. Especially in times of great adversity, the possibility that things might change and get better can imply greater hope (Ludema, Wilmot & Srivastva, 1997;Scioli et al., 2011;Kadlac, 2015). During intractable conflict, for example, people need to believe that things can change to remain hopeful (Cohen-Chen et al., 2014). Fourth, similar to individual hope, social hope involves many different layers of experience, such as beliefs and assumptions, emotions, mobilization and values. For example, there are many shared narratives surrounding social hope, i.e., stories that we share to depict what a positive or alternative future could look like (Smith, 2015;Torres & Tayne, 2017). Moreover, the tendency to develop hopeful thoughts and assumptions can be taught, especially during childhood (Snyder, 2002;Webb, 2010). Similarly, groups of people can share the same hopeful emotions, i.e., a feeling of transcendence, belonging, trust and possibility (Bar-Tal, 2001;Benzein, Norberg & Saveman, 2001;Boukala & Dimitrakopoulou, 2017). Moreover, shared hope can imply a strong motivation for the mobilization of large groups of people, for example, during social conflict or in addressing societal issues (Ludema, Wilmot & Srivastva, 1997;Pecchenino, 2015;Stevenson & Peterson, 2016).
Although individual and social hope share important components, social hope usually functions somewhat differently. In the experience of social hope, hopers usually do not receive feedback on their progress as often, easily or quickly as compared with individual hopers. As a result, social hope can have unexpected effects and remain influential long after the initial 'hopers' have moved on (Drahos, 2004). Moreover, shared hope can be somewhat more stable or long-term, as temporary or individual doubts and fears are less likely to translate to hopelessness, since the hope is shared across individuals and people can 'infect' each other with optimism (Wang, Joy & Sherry, 2013). Moreover, this means that trust is even more important, since people need to believe that others will align with their attempts to achieve shared goals (Braithwaite, 2004) (Fig. 4).

Internal Effects
There are many possible effects of a hopeful stance for an individual. For example, hope can be an important activating force (Schrank, 2002;Snyder, 2002;Aspinwall, 2005;Poels & Dewitte, 2008;Kadlac, 2015;McCormick, 2017) and can help people stay committed, even in times of adversity or in the absence of certainties (Benzein & Saveman, 1998;Zigon, 2009;Scioli et al., 2011;Ojala, 2012;Reichard et al., 2013). Many reasons have been mentioned explaining this motivational force. For example, hope is believed to usually entail an increased belief in our own and other people's capacities to create change, thereby making action seem more fruitful (Alarcon, Bowling & Khazon, 2013;Hornsey & Fielding, 2016;Stevenson & Peterson, 2016). Others stress that hope gives a 'zest for life', thereby helping a person to take action (Benzein & Saveman, 1998;Hammer, Mogensen & Hall, 2009). Additionally, the creative aspects of hope are assumed to open up non-conformist thoughts and behaviours (Kleist & Jansen, 2016). Likewise, the uncertainty of hope is believed to demand that the hoper remain active and thus prevents apathy (Ludema, Wilmot & Srivastva, 1997;Alarcon, Bowling & Khazon, 2013;Cohen-Chen et al., 2014). Again, others state that the positive feeling that accompanies hopefulness increases the 'thoroughness, efficiency and flexibility of problem solving' (Leung et al., 2009;Ojala, 2012). Finally, people who are hopeful are usually more focused on their goals and on information that might help them achieve those goals (Snyder, 2000a(Snyder, , 2000bHammer, Mogensen & Hall, 2009Webb, 2010Ojala, 2012Cohen-Chen et al., 2014. As such, hope generally makes people more inclined to reach goals that are important to them. Nonetheless, hope can also be quite passive (Hobbs, 2013). Generally, writers on hope assume that hopes based on denial or unrealistic fantasy are more likely to lead to apathy and to turn out to be counterproductive (Leung et al., 2009;Ojala, 2012;Hornsey & Fielding, 2016).
However, even unrealistic hope can help people by offering a chance for personal development and by offering positive feelings and comfort to get through difficult times (Folkman, 2010;Weingarten, 2010;Eaves, Nichter & Ritenbaugh, 2016). Hope has been linked to positive moods, physical and psychosocial well-being, coping, adjustment, self-esteem, resilience, trust, feelings of safety and a willingness to live (Benzein & Saveman, 1998;Webb, 2007;Duggleby et al., 2010;Folkman, 2010;Stevenson & Peterson, 2016;Griggs & Walker, 2016;McCormick, 2017). Alternately, hopelessness has been identified as an important feature of depression (Beck et al., 1974). However, hope can also make people prone to disappointment, thereby leading to feelings of loss and hurt if one's goals are not achieved (Kadlac, 2015).

External Effects
Both individual and social hope can have many effects that take place outside of the individual. For example, hope can help smooth social interactions, since hopefulness often goes hand in hand with outgoingness and an openness towards one's environment, which makes people more likely to forge relationships and get along with others (Halpin, 2001). Moreover, it is generally assumed that hope can help us deal with disagreement and conflict, which are inevitable in any relation (Bland & Darlington, 2002;Zigon, 2009). Furthermore, understanding and appreciating the hopes of others can increase empathy and thus create solidarity (Kadlac, 2015). This means that if social hope is effective, people will most likely be willing to collaborate to achieve their shared hopes or even to sacrifice part of their own wellbeing in the interest of the larger community (Braithwaite, 2004). Additionally, hope can function as a socially shared capital that infects others and thus creates a culture of hope (Wang, Joy & Sherry, 2013). It is therefore perhaps not surprising that hopeful pedagogies and education have been advocated to counter pessimistic or fatalistic sentiments within society (Halpin, 2001;Webb, 2010).
As a possible source for solidarity and understanding, hope can also be an incentive for virtuous or ethical behaviour. Of course, nothing stops people from hoping for unvirtuous goals, and hoping in and of itself does not need to be virtuous; however, hope can be used to maintain ethical (and often difficult) behaviour. Additionally, by resisting the idea that things cannot be different, hope can instil the desire to challenge and improve the status quo (Ludema, Wilmot & Srivastva, 1997). For example, sharing and talking about hope can help people create a 'counter-story', i.e., an imagination of possible alternatives to current circumstances (Kleist & Jansen, 2016;Torres & Tayne, 2017). Moreover, hope can 'place immediate circumstances in the context of broader and deeper possibilities', which can help us transcend our personal needs and create a desire to help others (Ludema, Wilmot & Srivastva, 1997;Eaves et al., 2014).
By creating trust in our collective ability, hope can mobilize large groups of people, for example, in the case of political protests or in addressing societal problems such as climate change (Bar-Tal, 2001;Braithwaite, 2004;Webb, 2010;Weingarten, 2010;Cohen-Chen et al., 2014;Kadlac, 2015;Hornsey & Fielding, 2016;Kleist 2016;Singh, 2016). Over time, such hopes can accumulate to become a form of cultural capital and create a shared feeling of identity. One example of this is the reference to the 'audacity of hope' in Barack Obama's rhetoric, i.e., 'a rhetoric of hope as the use of symbols to get Americans to care about this'country' (Atwater, 2007: 123). As such, hope can become a type of 'social imagining' that brings people together and guides collective action, often towards what is assumed to be a moral image of a better world (Ludema, Wilmot & Srivastva, 1997).
However, the effects of hope on a societal scale are not always positive, since it can also be abused to manipulate people. By attributing hope or hopelessness to specific groups or developments, politicians can, for example, discursively create and strengthen divides within society (Boukala & Dimitrakopoulou, 2017). Moreover, by creating vague hopes of 'greatness' without exactly explicating what this should look like, people can be mobilized towards goals that will hurt them on the long run (Sleat, 2013). Furthermore, if collective hope is systematically disappointed, this can result in 'a widespread sense of affective malaise' or societal disillusionment (Kleist & Jansen, 2016) (Fig. 6).

The Object of Hope
The object of hope has quite a peculiar place in the hoping process; although it is what hope is ultimately aimed at, we often do not need to know exactly what someone is hoping for to understand their general hopeful feeling. However, there are some general distinctions to be made, which also affect how we characterize the overall experience.
A first important remark is that there does not always need to be a clear, explicit object to hope. Many theories differentiate between particularized hope, which is focused on a specific goal, and generalized hope, which is more a global feeling that there is some positive future we long for without exactly knowing what that future will look like (Benzein & Saveman, 1998;Elliot, 2007;Kadlac, 2015). In French, this is the difference between individual, specific 'espoir' and a more general, fundamental 'espérance' (Webb, 2010). While the first is usually short-term and bounded by real-life limitations and conditions, the second is a more underlying, robust feeling (Halpin, 2001;Hammer, Mogensen & Hall, 2009).
Having an object to our hope does not necessarily require much involvement or engagement. One might hope to contribute to mitigating climate change, but as long as one does not attach any consequences to this hope, it remains largely abstract and passive. It is only once one starts to translate hopes into goals that the object becomes a tangible and engaged part of hoping. Goal-setting, i.e., translating desires into tangible outcomes to be pursued, is therefore an important part of many hope theories (Snyder, 2000a(Snyder, , 2000bSchwartz & Post, 2002;Leung et al., 2009;Griggs & Walker, 2016). Practising with goalsetting is an important part of learning to be reasonable in one's hopes (Snyder, 2000a(Snyder, , 2000bWebb, 2010;Kerrett, 2016). Functioning as tangible and concrete benchmarks, goals allow people to test their abilities and control, thereby providing them with important information about what they can realistically hope for and helping them to maintain hope in the future (Luthans & Youssef, 2007;Leung et al., 2009;Pecchenino, 2015). Moreover, goalsetting can help individuals and groups of people clarify what their desires truly are and whether their hopes are still aligned (Ludema, Wilmot & Srivastva, 1997;Kadlac, 2015).
Theoretically, just about anything we can imagine could be an object of hope. However, some writers draw attention to specific types of objects that might otherwise be overlooked. For example, an object of hope can be both individual, shared or of someone else (Benzein, Norberg & Saveman, 2001;Du & King, 2013); lies most often in the future but can also be in the present or past (Benzein & Saveman, 1998;Hammer, Mogensen & Hall, 2009;Webb, 2010;Ojala, 2012;Hornsey & Fielding, 2016;Griggs & Walker, 2016); and can be categorized into a prevention goal, i.e., something we want to avoid, or a promotion goal, i.e., something we want to achieve (Poels & Dewitte, 2008;Leung et al., 2009;Hornsey & Fielding, 2016).
In addition to ideas about what the object of hope can be, there are also many ideas about what the object of hope should be. Mentioned most often in this regard is that the object of hope should be realistic, i.e., sensible and attainable (Weingarten, 2010;Hobbs, 2013), and significant to the hoper (Webb, 2013;Griggs & Walker, 2016). Moreover, to count as a virtuous hope, it is claimed that the object should be about virtuous objects such as moral progress, humanization, salvation, or a more just society (Webb, 2010;Edara, 2015;Insole, 2015;Kadlac, 2015;Torres & Tayne, 2017).
Moreover, the mere possibility of attaining a hoped-for object can exert a normative influence on our behaviour (Ludema, Wilmot & Srivastva, 1997;Elliot, 2007;Torres & Tayne, 2017). For example, even the possibility of a cure for a disease can be used to tell people they ought to seek treatment as soon as possible (Cantor, 2006), or the imagination of a peaceful, prospering society can be used to persuade people to vote or become politically mobilized (Drahos, 2004). Here, the possibility of the object of hope seems to put people in a position where they are deemed responsible to act on it, even if perhaps they themselves feel reluctant to do so (Fig. 7).

The Complete Classification Matrix
In this study, we have discussed two different approaches to characterizing hope, which together elucidate seven important domains of the hoping phenomenon. The first approach focuses on what thinkers in this tradition assume is the most essential part of hope: the individual experience. This approach aims to distil the most necessary elements of this individual feeling. The second approach defines hope as a context-dependent process and assumes that to understand what hope is, we also need to know its sources and outcomes, understand the interplay between the internal and external dimensions, and know what object it is focused on. The seven components that follow from our classification matrix (see Fig. 8) are internal and external sources, the individual and social experience of hope, internal and external effects, and the object of hope. There are numerous examples of these components, and herein we have discussed some of the most-often mentioned examples. This overview is not exhaustive but aims to offer a structured overview of the characteristics ascribed to hope in the current literature. All in all, we can understand hope as a broad phenomenon comprising a process from source to experience and outcome, which has both individual and social aspects and is affected by its object. The individual experience of hope is an important part of this process and might often feel more central and essential to the individual hoper. However, to fully understand what hope can be, it is important to be aware of the context in which it arises.

Existing Theories and the Classification Matrix
How can this classification matrix be used to inform research on hope? Of course, each study and discipline has its specific focus, and not all dimensions of this classification matrix are immediately relevant in each context; however, being aware of a broader understanding can show which dimensions might be overlooked. Here, we will briefly discuss a few well-known theories on hope and how they relate to our classification matrix.

Positive Psychology: Snyder's Hope Theory
The hope theory posited by psychologist Snyder is well known and often used, especially within the field of positive psychology. Defining hope as 'a positive motivational state that is based on an interactively derived sense of successful (a) agency (goal-directed energy) and (b) pathways (planning to meet goals)' ' (2000b: 8), this theory focuses mostly on the internal sources, experience and effects of hope. Concerning the internal experience, Snyder's theory assumes that hope involves a positive probability estimate, i.e., high agency, and a positive response to uncertainty, i.e., finding different pathways in the event of setbacks. Snyder also focuses on different layers of hope and favours the influence of cognition and motivation over that of emotion. In regard to internal effects, this theory focuses on action tendencies, and less so on for example, meaning, personal development and comfort. Moreover, this theory offers openings for research on internal sources of hope, especially those focusing on previous experiences. Although external sources of hope are recognized as being possibly important, they are not recognized as inherently affecting what it means to hope. All and all, there are several parts of the broader hope phenomenon that attract less attention in this theory. First, the social components of hope are either rarely mentioned or not mentioned at all. Additionally, the object of hope is not explicitly mentioned as being important in this theory. Additionally, several elements of the individual process, such as different sources and effects and the experience of desire, are not elaborated upon.

Context
External Internal

Process Sources
Past experiences

Experience
Probability Uncertainty

Cognition Motivation
Effects Behaviour

Herth's Hope Theory
The theory that is most often used within nursing comes from Herth. She defines hope as 'a multidimensional dynamic life-force characterized by a confident yet uncertain expectation of achieving good, which to the hoping person, is realistically possible and personally significant' (Herth, 1992(Herth, : 1253. This theory, as well as important works within nursing, has a strong focus on expectations (i.e., probability estimate of the internal experience); on behaviour and comfort, such as healthy living and medicine adherence (i.e., internal effects); and on external sources of hope, for example, on the support that is provided by friends and family, health care providers, scientific advancements and some form of transcendence or spirituality. In some instances, there is also attention given to the object of hope, for example, concerning the question of whether people hope for something specific or have a more general sense of hopefulness and how large and significant the object of hope is to the hoper. The theory opens up the possibility for research on other dimensions of the hope phenomenon, such as internal sources, social experiences and external effects, yet these are not inherently embedded within Herth's theory.

Social Sciences
Within the social sciences, there is much more heterogeneity in how hope is defined, perhaps partly because the topic is less common, and the research therefore somewhat more fragmented. Within political science and anthropology, the focus is, perhaps unsurprisingly, on the external side of the hoping phenomenon, i.e., external sources, such as social unrest, politics, culture and history; the social experience of hope; and external effects, such as societal mobilization, solidarity through social bonding and social identity through shared meaning. To a lesser extent, there is a focus on the object of hope, specifically as it relates to being aware of the normative effects of goalsetting.

Context
External Internal

Discussion
Across disciplines, awareness is growing that subjective experiences such as hope have a strong explanatory power in regard to individual and social behaviours. Consequently, the number of studies on hope is quickly growing. However, an interdisciplinary framework was hitherto lacking, which hindered interdisciplinary and practical research on the meaning and role of hope in context. In this study, phenomenographic analyses were used to understand how different disciplines characterize hope and how these different approaches are related. The results show that we can differentiate two approaches, which together elucidate the following seven important components to the hoping phenomenon: internal and external sources of hope, the social and individual experience of hope, internal and external effects, and the object of hope. Each of these components in turn covers several themes, subthemes and examples. This classification matrix can be used to increase the awareness of the broader meaning of hope across scientific disciplines and perhaps even more importantly, the awareness of how people experience hope in their daily lives. Not all components will be (equally) important in all inquiries into hope; however, someone interested in the topic will understand the parts better when being aware of the whole. Moreover, this overview will hopefully support and ease collaboration as well as comparisons between and within different disciplines. As such, it can be used to amplify their value for understanding and tackling practical societal issues.
An important implication of these results lies in the way hope is measured in applied and scientific research. Common instruments, especially from the field of psychology, for example, make no mention of the social and societal context in which hope arises or the object to which it ascribes, while this context might be vitally important for understanding what hope means to people. When measuring hope or developing instruments to measure it, researchers could be well-advised to take note of the broader understanding of the topic, to prevent that important characteristics might be overlooked. As such, future research might also find correlations between hope and other states or circumstances which were hitherto overlooked. Similarly, when practitioners use hope to further a social agenda or achieve social change, for example in the case of sustainability, wellbeing or a political goal, it is important to take note of the different ways in which hope affects individuals as well as society as a whole. This not only helps to appeal to hope more effectively, but also to prevent disappointment, disillusionment and possible resulting social unrest.
Future research could further these insights by investigating to what degree the different characteristics of hope play a role in specific contexts, cultures and groups. Also, it could be worthwhile to use phenomenographic methods to study the meaning of hope using different search engines or in more specific bodies of literature, or in regard to a specific topic of scientific discipline. The aim of this study was to offer an interdisciplinary overview of different perspectives of hope across ten different scientific disciplines, and was therefore not exhaustive nor focused in depth on different perspectives within disciplines. Yet, future research could focus more extensively on different perspectives within disciplines. Lastly, these insights could be used to develop more comprehensive and valid instruments covering more or even all the domains of hope mentioned here.
Although we have tried to be as thorough, concise and inclusive as possible, there are several limitations to this study. First, and most importantly, creating a classification matrix to reflect an increasingly vast and complex body of literature necessarily requires simplification and some degree of subjectivity. This classification is by no means the only possible way to portray how different characteristics of hope are related. However, the aim of this study was not to definitively state what hope is but to offer a comprehensive but clear overview of which characteristics are ascribed to the concept by different people and how these perspectives are related. This overview might change over time and with progressive insights, yet it hopefully offers one step towards a fuller and more integrated understanding of hope.
There are also some methodological issues that should be taken into consideration. For example, in collecting the sources for this study, we have tried to systematically select the most relevant works; however, in the process, we had to rely both on the previously determined categories of, for example, Web of Science, as well as on our personal evaluation of these works. Moreover, by using only one search engine, it is possible that our data selection was not exhaustive with regards to all relevant literature on the topic of hope within certain disciplines. However, it should be kept in mind that in our selection, we did not aim to be exhaustive but to be sufficiently representative of the current literature on hope and to offer a sufficient amount of diversity. Considering that we have included 66 works from ten different disciplines, we conclude that the variety of included works is comprehensive. Moreover, in analysing the texts and subsequent themes, some degree of subjective interpretation was inevitable. We have tried to increase the reliability of this study through triangulation, i.e., by combining multiple observers and methods. Last, by only including academic articles, we might have missed theories that have been discussed only in books as well as lay-people's experiences of hope. However, since many of the included articles contain reviews of existing literature, including books and studies on people's experiences of hope, we still consider these perspectives.
All in all, it is a tricky business to try to give a clear and structured overview of something as complex, elusive and human as hope. Nonetheless, the academic and societal value of understanding one of the most powerful incentives of human behaviour is simply too large to forego an attempt at a better understanding.