In March 2020, the world stood still for a moment. On March 11th, the World Health Organization (WHO) declared the outbreak of SARS-CoV-2 a global pandemic. The novel coronavirus threatened the health, livelihood, and survival of billions of people worldwide. The elderly and immune-suppressed were particularly susceptible to the virus. To protect their citizens, many governments implemented so-called lockdowns and mandated that everyone who could must stay home.

The virus was not only a risk to people’s health. Some groups who were not particularly susceptible to severe COVID-19 still found themselves in challenging situations. For example, healthcare providers in many countries had to work under difficult conditions. Often, they had to work overtime and without proper personal protective material such as medical gloves and masks, as there was a global shortage of such products. Children were deprived of access to schools in many countries, increasing educational inequalities. Some people were at risk of losing their livelihood because they worked in sectors severely affected by the lockdown, such as event organization, culture, and the arts. Most of us would likely say that those groups can be described as vulnerable in the context of the pandemic. But what exactly does this term mean?

1.1 The Importance of Vulnerability

Introduction partially based on Martin et al. (2014).

This book examines the question of what vulnerability is, and assesses why and when it matters from a moral perspective. This is an important endeavor: the concept of vulnerability is invoked frequently, and it plays a particularly important role in the field of bioethics. Some individuals and groups in specific situations or domains, such as medical research and healthcare, are frequently described as vulnerable and should, as a consequence, be afforded additional attention and special protection (Hurst 2008; Solbakk 2010).Footnote 1 Yet justifications vary as to why these individuals should be regarded as vulnerable. For example, vulnerability is commonly ascribed to those in medical research or healthcare who are more likely to be exploited (Macklin 2003), who are unable to protect or safeguard their own interests (Nickel 2006), who lack basic rights and freedoms to choose the course of their life (Zion et al. 2000), or who are at risk of having unequal opportunities to achieve their greatest possible health and quality of life (Danis and Patrick 2002). As a consequence of their situational vulnerability (i.e., their vulnerability in a specific situation or context), it is held, they should be afforded additional attention and special protection, for example, when they enroll in medical research or when they are hospitalized.

However, the view that only some individuals are vulnerable in specific situations or domains has been criticized, on the ground that describing only some people as vulnerable disregards the fact that everyone is vulnerable by their very nature. As Marion Danis and Donald Patrick note, “an approach that seeks to acknowledge multiple views but casts only some as vulnerable is insufficient – it ignores the fact that vulnerability is universal and that the failure to acknowledge this universality is divisive. Labeling individuals as ‘vulnerable’ risks viewing vulnerable individuals as ‘others’ worthy of pity, a view rarely appreciated. Moreover, the vulnerable are not ‘others,’ for no one is invulnerable” (Danis and Patrick 2002: 320).

According to the proponents of ontological or universal vulnerability, to describe only some as vulnerable ignores the fact that humans are all vulnerable, to some extent.Footnote 2 This view is intuitively appealing. After all, we may experience various unpleasant events during the course of our lives: we may seriously hurt ourselves; we may fall temporarily sick or suffer from life-threatening diseases; we may get hurt in natural catastrophes; we may be harmed by other living beings; we may be treated disrespectfully and have our autonomy disregarded; and finally, our lives could end at any moment. All these incidents seem to refer to what we would intuitively call “vulnerability.” Indeed, most living beings are vulnerable to harm, such as diseases, attacks, rights violations, and ultimately, death.

Universal vulnerability is characterized as an intrinsic property of all human beings due to our nature (Gert 2004), it forms a part of the human condition (Callahan 2000; Kottow 2003), or expresses the finitude of the human condition (Rendtorff and Kemp 2000). Vulnerability is therefore mostly (but not exclusively) linked to having a body (Kemp 2000; Hoffmaster 2006), to the possibility of encountering harm (Harrosh 2012), or to being mortal (Rendtorff and Kemp 2000; Thomasma 2000; Rendtorff 2002).

These conflicting conceptions of vulnerability show that, despite its frequent use, the concept remains unclear. Who is vulnerable, and why? Thus, one major challenge when defining vulnerability is due to its unclear scope: does it encompass everyone by their very nature, or does it concern only a few individuals in particular domains who should be afforded special protection and attention? The difficulty is that the two disparate interpretations of the scope of vulnerability—vulnerability encompassing everyone versus vulnerability as a property of only some—seem contradictory and thus irreconcilable.

This conflict between these two different conceptions of vulnerability, along with the presence of differing definitions in the literature, have far-reaching negative consequences. It may lead us to overlook some individuals who really ought to be recognized as vulnerable and who will otherwise be denied the special protection they may need in specific contexts and situations (such as healthcare). Conversely, it may also lead to the overprotection and stigmatization of those falsely described as vulnerable.Footnote 3 Finally, an unclear concept of vulnerability in the field of bioethics may also elicit opposition to the very idea that some individuals in specific domains are in need of special protection and additional attention. After all, if all human beings are vulnerable by their very nature, then how can we justify additional attention and special protection only for some? Due to the underdetermined scope of the concept, it remains an open question whether vulnerability has some normative pull, or whether it is instead a descriptive concept. Thus, it is unclear whether vulnerability entails some action-guiding component, or whether it simply describes the human condition, without any normative implications.

The problem concerning the scope of vulnerability and its moral implications becomes even more evident when considering UNESCO’s 2005 Universal Declaration on Bioethics and Human Rights, which deals with the link between bioethics and human rights. Article 8 states: “In applying and advancing scientific knowledge, medical practice and associated technologies, human vulnerability should be taken into account. Individuals and groups of special vulnerability should be protected and the personal integrity of such individuals respected” (UNESCO 2005). Here, UNESCO refers to a notion of human vulnerability which encompasses everyone by their nature; on the other hand, it invokes a notion of special vulnerability which involves only some individuals. Yet neither of these concepts is further defined. This significant example, as I see it, highlights the need for a definition of universal vulnerability which can simultaneously justify special protective measures only for some. As Jan Helge Solbakk noted, “paradoxically speaking, for the principle of vulnerability not to lose its moral force it needs to be embedded in the human condition of unalterable vulnerability” (Solbakk 2010: 236).

The use of vulnerability in ethics may arouse skepticism. After all, if there are different interpretations of its scope or disagreements as to how it should best be understood, is there not a risk of ethicists talking past each other when employing the term? And would it then not be advisable to abandon the concept of vulnerability altogether (Vladeck 2007)? I hold that eliminating vulnerability language—whether from our common vocabulary or from the field of bioethics in particular—is both unrealistic and undesirable. As has been argued in the literature, the concept of vulnerability, despite its vagueness, is worth holding onto:

The concept of vulnerability has been used so extensively, and so inconsistently, that it is tempting to conclude that it is incapable of providing any meaningful ethical guidance. As a practical matter, however, it is unlikely that vulnerability language will disappear any time soon. Even if there is no consensus on what vulnerability actually means, calls for “protecting the vulnerable” seem to have an intuitive ethical appeal, and are therefore likely to continue. (Coleman 2009: 14)

Although vulnerability is currently under-theorized and insufficiently defined, there is nonetheless agreement that the concept captures something sufficiently morally important about individuals and groups to call for a moral response. Therefore, bioethics is in need of a robust account of vulnerability (Rogers et al. 2012).

As I argue in this book, the concept of vulnerability—and in particular, situational vulnerability—fulfills an important and useful function: it orients us toward those individuals who, in specific situations, are in need of additional attention and special protection. Vulnerability thus functions as a “needed moral safeguard” (Marco 2004: 82) insofar as it singles out those individuals who are likely to be denied what they are due. And these individuals, as I show in this book, are not only humans, but also sentient animals.

Indeed, it has been argued by some philosophers that animals share one or several properties that are constitutive of vulnerability. However, the application of vulnerability to animals raises important questions regarding ethical implications. For example, would an extension of vulnerability to animals imply that animals should benefit from similar protections as humans, as has been argued (see, e.g., Johnson 2013; Ferdowsian and Choe 2013; Ferdowsian and Fuentes 2014)? Or does animal vulnerability count less than human vulnerability, as proposed by some (Kottow 2004)?

1.2 Structure of the Book

The aim of this book is to propose answers to the questions and problems outlined above. In the following seven chapters, I analyze what vulnerability consists in, indicate to whom it can be ascribed, and identify the relevant circumstances to be considered. I propose a definition of vulnerability that resolves the conflict between the two diverging understandings of vulnerability in the literature, namely, vulnerability as a property of everyone versus vulnerability as a property of only some individuals or groups in specific situations. In addition, I discuss the link between vulnerability and morality, placing special emphasis throughout the book on the moral implications of animal vulnerability. As I will show, vulnerability language not only is useful in the case of humans, but can be fruitfully extended to sentient animals. Specifically, I focus on animal vulnerability in four chapters, because animal vulnerability has thus far been less systematically explored than human vulnerability. I thus outline in the following chapters how vulnerability should be understood in bioethics while proposing how and why it matters from an ethical point of view for both humans and animals.

To this end, I adopt a systematic approach: I analyze the concept of vulnerability and then construct an account of how vulnerability should best be understood if it is to serve as a fruitful concept in ethics. This means that the account of vulnerability proposed here does not necessarily cover everything which is meant by “vulnerability” in everyday language; rather, it shows how we ought best to understand and employ the term in the field of bioethics. The account of vulnerability presented in this book is thus, to a certain extent, ameliorative. I argue that the problem concerning the scope of vulnerability can be resolved, demonstrating that both extant conceptions—that is, universal and situational vulnerability—refer to the very same concept, with different likelihoods of manifestation. The definition of situational vulnerability is thus based on the definition of universal vulnerability.

The structure is as follows. In Chap. 2, I distinguish among various conceptions of vulnerability found in the literature, I outline the entities to which vulnerability can be ascribed, and I list the usages to be adopted going forward. I show that vulnerability is a dispositional concept, and so we must distinguish among the reasons why an entity is vulnerable, the conditions of manifestation, and the actual manifestations of vulnerability. Furthermore, I discuss the type of definition most suitable for capturing what vulnerability means in bioethics, and I list the conditions it should fulfill.

In Chap. 3, I present my definition of universal vulnerability. I argue that generally vulnerable beings possess certain fundamental interests, namely welfare and agency interests, which could potentially be frustrated—be it by the individuals themselves, by unlucky circumstances, or by moral agents or moral patients (Martin et al. 2014: 55). Correspondingly, I distinguish among different types of manifestations of vulnerability—that is, states which occur if these interests are frustrated, notably unpreventable or morally justified harm, wrongful harm, and mere wrongs which do not involve any harm (the latter defined as cases where someone’s welfare or agency interests are unjustifiably disregarded by a moral agent, but where the consequent state does not involve any measurable or subjectively perceivable harm).

If moral agents have power over the satisfaction of the welfare and agency interests of others, then they also have a duty to consider them in a fair way, I suggest. Accordingly, we are no longer talking about mere interests; rather, these fundamental welfare and agency interests have the status of legitimate claims—with corresponding duties. Those with power over the claims of others are not necessarily nominated moral agents who stand in a relationship to the vulnerable beings. Sometimes, we hold a certain power over the satisfaction of claims of individuals far away from us, along with a corresponding duty to consider them fairly.

How is this definition of universal vulnerability linked to situational vulnerability? I argue that those who are comparatively more likely to have their legitimate claims unjustly considered should be regarded as particularly vulnerable in a specific situation or context. The increased likelihood of having one’s claims unfairly considered may be due to prejudices, discriminatory attitudes, ignorance, neglect, and the like. As a consequence, these individuals are more likely to incur unjustified harm or mere wrongs not involving harm. Qua particularly vulnerable, they should be afforded additional attention and special protection to decrease their risk of incurring unjustified harm and to ensure that they receive what they are due.

The account of vulnerability presented here has several advantages. It allows for a distinction between universal and situational vulnerability, the latter being embedded in the former. It explains why some vulnerabilities matter morally and require action, while others are unavoidable or unalterable parts of life. Furthermore, the lens of vulnerability can be directed toward animals, thus providing insights into the field of animal ethics. After all, it seems a worthwhile endeavor to systematically investigate how a moral concept fruitfully used for humans can be extended to animals.

Chapter 4 is dedicated to the topic of whether animals can fulfill the conditions of my definition of universal vulnerability. I answer this question affirmatively, and I inquire whether animals can hold legitimate claims. I show that sentient animals—the focus of Chaps. 4, 5, 6, and 7—have welfare interests and sometimes agency interests. I argue, consequently, that moral agents owe direct duties to animals, and that speciesism (i.e., discrimination based on species-membership), ought to be rejected. This implies that like interests should count alike, regardless of their bearer’s species. This leads me to draw up a list of basic pro tanto claims of animals that should be justly considered by moral agents who have power over the satisfaction of these claims.

Thus, I establish in Chap. 4 that animals are generally vulnerable. However, the more important question, from an ethical perspective, is whether animals—like some groups of humans—can be situationally particularly vulnerable and should therefore be afforded additional attention and special protection. I demonstrate that some groups of animals are indeed comparatively more likely to have their claims unjustly considered, as speciesist attitudes and prejudices often prevail in the treatment and consideration of some non-human animals. To illustrate this point, I focus on three groups of animals in Chaps. 5, 6, and 7: animals used for food, animals used in research, and wild animals. This selection is no accident; rather, the focus on these specific groups of animals serves to illustrate different manifestations of vulnerability—namely, unjustified harm, justified harm, and unpreventable harm.

The first group of animals I discuss are animals used as food sources. The rearing and killing of animals for the food industry often involves tremendous harm. Chapter 5 discusses whether using animals for human consumption can be ethically justified. I argue that many—but not all—uses of animals as food sources are morally problematic, as animal agriculture is often a deeply speciesist practice. This does not imply that we must all necessarily become strict vegans, however; there are some non-harmful uses of animals which can be ethically justified. Nonetheless, I conclude that we should recognize many groups of animals commonly used for food as particularly vulnerable. Indeed, their claims do not receive the consideration they are due, and I make a case for increasing their protection accordingly.

In Chap. 6, I turn to the question of whether the harm that animals used in research suffer throughout scientific studies can be ethically justified, or whether we should regard these animals as particularly vulnerable research subjects who should be afforded additional attention and special protection. After all, using animals for research, which improves both human and animal health and welfare, seems prima facie more ethically justifiable than killing animals for food. However, I contend that not all animal research discounts animals’ claims in a legitimate manner; on the contrary, much of the research currently conducted with animals is ethically unjustified. The currently implemented research requirements, I explain, are often speciesist and thus insufficient from a moral point of view. Therefore, we should designate many groups of research animals as particularly vulnerable. For research with these animals to become more ethical, it must become more similar to research with humans, and I outline what this could look like in practice.

Chapter 7 discusses whether the various forms of harm experienced by wild animals in their daily lives—typically viewed as inevitable and unpreventable forms of suffering—are justified from an ethical point of view. I argue that not all the harms endured by wild animals are ethically justified, even if they are caused by natural forces or by other animals rather than by moral agents. I propose that, in some cases, moral agents have a duty to intervene in nature and to help reduce the harm experienced by wild animals, even if humans are not the source of this harm. I further defend a duty of compensation if direct or indirect harm is caused to wild animals as a result of human activity.

In Chap. 8, I summarize the main ideas and arguments of the book. I explain what extending vulnerability language to animals adds to moral debates in animal ethics, and I adumbrate further applications of vulnerability discourse to other fields. Finally, I defend the book’s main arguments and views against potential objections.

One of the main ideas presented in this book is that different groups of both humans and animals can be particularly vulnerable in various settings. Commensurate to their increased vulnerability, they should be afforded additional attention and protection to ensure that they receive what they are due. That is, the definition of situational vulnerability I propose here is formal enough to be applied to various scenarios, situations, groups, and even species. It can be applied to various situations and events such as humanitarian crises, natural disasters, medical research, healthcare, as well as certain uses of animals. I will illustrate this point in the next chapter with three real-world case studies.