The rotten core of presentism

Recently, some have attempted to reformulate debates in first-order metaphysics, particularly in the metaphysics of time and modality, for reasons due to Williamson (Modal logic as metaphysics, Oxford University Press, 2013). In this paper, we focus on the ways in which the likes of Cameron, Correia and Rosenkranz, Deasy, Ingram, Tallant, Viebahn, inter alia, have initiated and responded to attempts to capture the core of presentism using a formal, logical machinery. We argue that such attempts are doomed to fail because there is no theoretical core to presentism. There is no single view or family of views that is presentism.


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presentists assert that only present entities exists, i.e., 'everything is present'. At this point, enter Williamson (2013: pp. 24-25), who objects to presentism because of problems with interpreting the predicate 'is present' in statements of the view. This line of objection has generated a lively metaphilosophical sub-literature (e.g., Cameron 2016; Correia and Rosenkranz 2015, 2018: pp. 59-71, 2020aDeasy 2017Deasy , 2019Ingram 2019: pp. 33-35;Tallant 2019;Viebahn 2020;inter alia). Correia and Rosenkranz (2015) and Deasy (2017) endorse Williamson's objection and look to characterise presentism differently; they try to capture what they take to be the presentist insight using a range of logical machinery. The result is a shift to a debate concerning two other theses, temporaryism and permanentism, and how to use these to capture presentism and non-presentism. Cameron (2016) responds directly to Deasy and argues that the temporaryism-permanentism debate does not get to the heart of what is at issue between presentists and non-presentists. Deasy (2019) replies, arguing that Cameron's characterisation is equally flawed: it counts some presentist views as non-presentist (and vice versa). Similarly, Tallant (2019) argues that Correia and Rosenkranz, Deasy, and Williamson approach the issue from the wrong perspective, and that each of their models fails to capture presentism. In other words, none of these theories (x, y, and z) adequately capture what is presentism (what is F).
This sub-literature presupposes that there is a core presentist insight to be captured. The main objective of this paper is to undermine this literature by showing that there is no core presentist insight to be argued over. There is no F-no single view that the likes of Cameron, Correia and Rosenkranz, Deasy, Tallant, etc. can try to capture. Their metaphilosophical project is built on sand. 1 To make our case, we sketch the proposal that the presentist-eternalist dispute be understood in terms of the temporaryism-permanentism debate (Sect. 2), and make explicit that proponents and opponents of this new debate claim that there is some core of presentism that they can attempt to capture (i.e., with temporaryism). We then introduce a range of incompatible ways that presentism is described, to show that there is no one view that is presentism (Sect. 3). Then, we show that there is no common core to views that marks them as distinctively presentist (Sect. 4). And, to be clear, when we say that 'presentism is rotten' and that 'it has no core', we mean that there is nothing distinctive-no philosophically interesting, unifying featurein virtue of which it is correct to call these views 'presentist'. Finally, we consider objections (Sect. 5).
1 3 Synthese (2021) 199:3969-3991 2 Presentism-eternalism or temporaryism-permanentism According to Deasy, much debate in the philosophy of time turns on answers to 'Are there past things?' and 'Are there future things? ' (2017: p. 378). Deasy thinks that we would be better served asking 'Do things begin to exist?' and 'Do things cease to exist? ' (2017: p. 390). Deasy recommends a distinction: presentists answer 'yes' to both questions; presentists believe that things begin to exist and that things cease to exist. Eternalists answer 'no' to both; eternalists do not believe that things begin or cease to exist (2017: pp. 390-1). The two attitudes can be framed in terms of a commitment to one of two distinct theses: transientism (a version of temporaryism) or permanentism. Transientism: Sometimes, something begins to exist; sometimes, something ceases to exist. (Deasy 2015(Deasy : p. 20742017: p. 390) In the formalism: S denotes the operator 'it is sometimes that case that', P denotes 'it was the case that', and F denotes 'it will be the case that'.
A∀x A∃y y=x (Deasy 2015(Deasy : p. 20742017: p. 391) In the formalism: A denotes the operator 'it is always the case that'. The presentism-eternalism debate is recast as a debate between transientists and permanentists. Presentism is characterised as A-theoretic transientism-the view that there is an absolute, objective present moment, and sometimes, something begins to exist and sometimes, something ceases to exist (2017: p. 391). Eternalism is characterised implicitly as a B-theoretic permanentism-the view that there is no absolute, objective present moment, and always, everything always exists (Cameron 2016: p. 111). Cameron (2016) and Tallant (2019) challenge Deasy's characterisation. We think that their challenges have the same shape; both object that the new debate does not capture what is at issue in the original debate. This is key to what follows. To illustrate, here is Cameron: 'I don't think that the debate over Permanentism captures the debate between the presentist and the eternalist. Permanentism is a thesis about whether or not things come into or go out of existence. It says that they do not: nothing comes into existence, and nothing ceases to be, because it is always the case that each thing that exists is something that always has existed and always will exist. But, surely the presentist can believe that. Presentism is compatible with the claim that the ontology of the world is fixed in time: that there are no changes to what there is-nothing coming into being, or ceasing to be. … Permanentism is not what is at issue between the presentist and the eternalist, then, for they each can accept it. ' (2016: pp. 111, 114) 2 Thus, the presentism-eternalism debate cannot be recast as a debate between transientists and permanentists because, although transientism is incompatible with permanentism, presentism is compatible with permanentism. In other words, Cameron believes that there is something, presentism, which is not adequately captured by A-theoretic transientism (and the denial of permanentism).
Tallant's challenge is similar. For Tallant, Deasy's characterisation of presentism as A-theoretic transientism fails because 'definitively non-presentist scenarios' count as presentism (2019: p. 412). Put differently, there is an underlying F-presentism-and contra Deasy, it is not captured by temporaryism or permanentism because non-F views-non-presentist views-are not properly characterised.
The suggestion that there is a core presentist insight, which can be used to 'test' putative characterisations, is not unique to those who challenge Deasy's reform. Indeed, Deasy (2019: p. 285) uses this sort of test in reply to Cameron, claiming: 'Cameron's proposed interpretations of Presentism and Eternalism mistakenly count certain Presentist theories as non-Presentist (or vice versa)'.
We think that the above indicates that proponents and opponents of the reformed debate have something in mind, some core presentist insight, when they assert that the reform does or does not capture the original debate. However, as we telegraphed at the outset: we do not think that there is a core presentist insight. In what remains, we argue for this conclusion.

The varieties of presentism
Now, we introduce a range of descriptions of presentism, showing that many have distinct, incompatible commitments. We think that this suffices to show that there is no one view that is presentism. Thus, one cannot object to (e.g.) A-theoretic 2 An anonymous referee has pushed us on the following question: Why should we suppose that Cameron, Deasy, et al., set out to capture 'a view', and not the truth about (e.g.) time and existence? One reason that we suppose the former can be illustrated by appealing to Tallant's (2019) brief description of his project in challenging Deasy's characterisation of presentism: I am going to proceed by demonstrating how definitively non-presentist scenarios would satisfy this alleged definition of presentism [i.e., Deasy's definition]. … [That the scenarios] are clearly non-presentist and yet compatible with Deasy's definition is all that I require in order to demonstrate that Deasy's definition of presentism is one that fails. ' (2019: p. 412). The only way that these non-presentist scenarios could realise that aim is if Tallant is trying to determine whether or not Deasy's characterisation of presentism is apt. And, to be clear, this is the intended reading of Tallant's argument. Further, as Cameron (2016: p. 114) puts it: 'Permanentism is not what is at issue between the presentist and the eternalist, then, for they each can accept it.' In the passage cited in the main text, Cameron is clear that he is discussing whether or not perman entism is what is at issue between presentists and eternalists. transientism that it fails to capture presentism, because there is no single view to capture.
There are many distinct statements of presentism, but this diversity has not been explored in the literature. This is striking, for there are myriad contradictory definitions. One potential explanation for this diversity is that all those cited below are being sloppy in their presentations of presentism. But such an explanation is extremely uncharitable and highly unlikely. All cited are professional philosophers; being careful with their words is central to what they do. Moreover, it seems clear from the work cited that much of the diversity has been provided deliberately and for theoretical ends. Another explanation can be given: there is no fixed view of presentism. That is more plausible and more charitable. Indeed, we think that there is no philosophical commitment that these putative presentisms have in common such that they merit membership of a class of views that we could call 'presentist'. (We argue for this in Sect. 4.) When we speak of there being no 'family' of views that we may call presentist, it is this thesis we have in mind.
Our methodology is familiar from other debates, e.g., parts of the literature on grounding. For instance, Koslicki (2016) argues that there is no unified notion of grounding, contra Schaffer (2009), by showing that there is no unifying feature shared by all alleged instances of grounding-no feature that unifies them as a single type of thing (see, also, Wilson 2015: p. 576). We make a similar move. There are a range of views in the philosophy of time: those who identify as presentists are correct that we should pay attention to what is present, what temporal passage is, and many other issues. But this leaves open whether 'presentism' picks out a single view, a family of views that share some feature, or if the term is now so elastic as to simply advert to a collection of views that share no core. We think that the last claim is correct. There is no single view or family of views that is presentism; we can still call views 'presentist' but in doing so we signal nothing of philosophical significance.
Though familiar, this methodology may appear controversial when deployed here. One might worry that, by showing that there is no unifying feature shared by all versions of presentism-no feature that unites them under one banner-we do nothing surprising. After all, one might expect to find a similar picture in many subliteratures with various conflicting statements of one theory. Consider, e.g., the correspondence theory of truth (CTT)-to pick an example from a different literature. We can point to CTT as a case of one theory with considerable variation. Put simply, CTT states that something is true when it 'corresponds to reality' (Lynch 2001: p. 9). But there are instances of CTT that propose different relata for both sides of the correspondence relation (cf. David 2016): some treat propositions as truth-bearers (the 'something' that has a truth-value), others say that mental representations or written sentences play this role instead; some instances treat facts as the bits of reality to which truths correspond, others say that states of affairs or objects are the relata. And different versions of CTT disagree about the nature of correspondence itself (cf. Kirkham 1995: pp. 120-40). In short, there is huge variation. Does this leave CTT in the same boat? And, since we could find many examples in other literatures, does this suggest that many debates face similar issues? If this is a widespread issue, what is the point of our paper?
The methodology is less controversial than appearances may suggest. For one, there is our specific target: the metaphilosophical debate, cited above. For another, the variation of so-called 'presentist' views is far more significant (as we demonstrate in a moment). Let us take these two issues in turn.
First, our main target here is a sub-literature built on the claim that there is a core of presentism, with arguments concerning whether a view has captured that core successfully. Now, if (e.g.) there were similar claims made in the literature on CTT (or another debate), and it turned out that there is no single view (or family of views) that share some feature, such that the term 'correspondence theory' is now so elastic as to simply advert to a collection of views that share no core, we would regard any attempt to capture that core to be similarly flawed. But our primary concern here is not with the mere fact that there is variation in statements of the view. (Let a thousand flowers bloom!) Our concern is with a metaphilosophical project that purports to capture a core of presentism when there is in fact no such core.
Second, even setting our first point aside, we think that the degree and scope of variation across versions of presentism is quite striking indeed. In the case of the CTT literature, we concede that there is variation. But-at least so far as we knowthere is no version of CTT that denies that truth consists in some kind of relation to reality. 3 Here we quote David (2016) on CTT at length to frame our approach: '[CTT] is the view that truth is correspondence to, or with, a fact-a view that was advocated by Russell and Moore early in the 20 th century. But the label is usually applied much more broadly to any view explicitly embracing the idea that truth consists in a relation to reality, i.e., that truth is a relational property involving a characteristic relation (to be specified) to some portion of reality (to be specified). This basic idea has been expressed in many ways, giving rise to an extended family of theories and, more often, theory sketches. Members of the family employ various concepts for the relevant relation (correspondence, conformity, congruence, agreement, accordance, copying, picturing, signification, representation, reference, satisfaction) and/or various concepts for the relevant portion of reality (facts, states of affairs, conditions, situations, events, objects, sequences of objects, sets, properties, tropes). The resulting multiplicity of versions and reformulations of the theory is due to a blend of substantive and terminological differences.' (our italics) We would agree that there is a core to presentism if we could find even such a broad way of characterising the view (in the same way that David says that there is a broad family of views that may be regarded as correspondence theories). But there is no such broad way to capture the views in the case of presentism. Without pre-empting much of what is to come: some presentists say that only present objects exist, others say that non-present objects exist; some say that only the present time exists, others say that there are other times; and so on. That being so, we think that even a broad characterisation of a family of presentist theories is beyond us. The strategy we pursue assumes an inference to the best explanation: the best explanation for the deep incompatibility between all existing formulations of presentism is that there is no core insight of presentism. 4 With our methodology now framed, we turn to the views themselves.

Objects and times
We begin with one characterisation as a stalking horse. Presentism is sometimes described as the view that 'only present objects exist' (cf. Here we treat 'only present objects exist'-or the logically equivalent 'no non-present object exists'-as an object-definition of presentism; the definition renders presentism a claim about when objects exist in time: an object exists in time only when the object is present. Thus: (1) Only present objects exist.
Some think that 'only present objects exist' applies only to physical or concrete objects (e.g., Tooley 2012: p. 25; Cameron 2015: p. 6). Others think that it extends to non-physical or abstract objects. So, we must make a preliminary clarification.
Or: for all x, if x is a physical or concrete object, then x is present.
Not all presentists accept (2). Tallant (2014) articulates a version of presentism on which abstracta, if they exist, are present objects; Craig (1997: pp. 36-37) comes close to defending that all objects (concrete or abstract) are present. Thus, one may defend (1) without accepting (2). Nonetheless, this is a small difference. It appears a side-question about abstracta, not a difference that is likely to motivate our claim that there is no single view (or family of views) that is presentism.
(1) and (2), are silent on whether there exist any non-present entities that are not objects. Some presentists hold that there exists a space-time structure that contains more than the present, whilst affirming that only present objects exist. Zimmerman (2011) endorses a view according to which there exist no non-present objects but there is a 'permeable cosmic jell-o' (2011: p. 200) identified with space-time that spans past, present, and future. This view denies that non-present objects exist, but treats all times as existing. Thus: (3) All times exist and only present (physical/concrete) objects exist.
However, others treat presentism as committed to the existence of only one time: the present. Saunders (2002: p. 278) and Sakon (2015Sakon ( : p. 1089) define presentism as the view that 'only the present exists'. And Cameron, when replying to Deasy, defines it as 'the view that everything that is located at all is located at the present time, and not located at any non-present time' (2016: p. 131). Since times are located (trivially, at themselves, given plausible topological assumptions), presentism is committed to the present as the only time that exists. Thus: ( 3) and (4) are incompatible. One accepts the existence of non-present times, the other rejects them. Nonetheless, both are dubbed 'presentism'.

From existence to reality
Some describe presentism as a view about what is real as opposed to what exists. This approach also comes in two versions: a claim about which times are real and a claim about which objects (entities) are real. We begin with the former. Sider (1999: p. 325), for instance, treats presentism as a thesis about which times are real: 'only the present is real'. Similarly, Merricks (2006: p. 103) describes it as the view that 'only the present time is real'. Zimmerman (2005) also suggests this sort of view when describing presentism as: ' [The] doctrine that all reality is confined to the present -that past and future things simply do not exist, and that all quantified statements that seem to carry commitment to past or future things are either false or susceptible of paraphrase into statements that avoid the implication.' (2005: p. 402) Thus: (5) Only the present time is real.
Many think that (4) and (5) are equivalent. But an auxiliary assumption is required for this equivalence: 'only the real exists'. We suspect the fact that this assumption is widespread explains why some slide between (4) and (5) without marking any difference (see, e.g., Hawley 2001: pp. 34, 52-53, for this in practice).
In addition, there are others who define presentism in terms of real objects (e.g., Sider 2001: p. 11): All times exist and only present (physical/concrete) objects exist.
Once again, we find significant variation across statements of presentism. (6) and (7) are incompatible. One is consistent with there being non-existent and unreal nonpresent objects, the other is not.
We should also mention Arthur Prior, regarded by many as a presentist (e.g. Lewis 2004: p. 4), who describes part of his view in terms of reality. (For further discussion of Prior's place in our argument, see Sect. 5.4.) Here is Prior: 'Before directly discussing the notion of the present, I want to discuss the notion of the real. These two concepts are closely connected; indeed on my view they are one and the same concept, and the present simply is the real considered in relation to two particular species of unreality, namely the past and the future. ' (1970: p. 245; our italics) Prior does not tell us how to understand the claim that there are two 'species of unreality' (past and future). On a literal reading, it marks a three-fold distinction in what is real and unreal. We pursue this interpretation here (see Smith 2002: p. 123, for a similar interpretation). 5 Thus: The present is real, the past is unreal (in one sense), and the future is unreal (in another sense).
(5) and (8) are plausibly distinct when we consider the two species of unreality (past and future).

Existence presentism
Yet another way to characterise presentism, presented by Merricks (2007) and developed by Tallant (2012Tallant ( , 2014, draws a distinction in kind between positions adopted by presentists and eternalists. Presentists and eternalists disagree about what it is to exist. According to Merricks, 'presentists should … say that existing at the present time just is existing ' (2007: p. 125). Similarly, Tallant offers a version of presentism which affirms that existence is presence, clarifying the view by stating: 'Presence is existence is an identity claim' (2014: p. 494). Finally, consider Zimmerman's claim, in articulating presentism, that 'to be present just is to be real or to exist ' (1996: p. 117). In each case, the claim is that this helps mark a genuine distinction between presentism and eternalism. For Merricks, presentists should claim that existing at the present is existing, whereas eternalists must deny this claim. Thus: (9) Existence is presence. (To exist just is to be present.) Since (9) is taken from Merricks's statement of presentism, we may add that this version of presentism is committed to the thesis that there is no such thing as the present time. Here Merricks is explicit: 'presentists should deny that there is anything at all … that is the present time, just as they should deny that there are past times or future times ' (2007: pp. 124-5).
There are important differences to be highlighted. (9) is distinct from (2) and (3), viz. 'only present (physical/concrete) objects exist' and 'all times exist and only present (physical/concrete) objects exist'. (2) is compatible with the existence of atemporal abstracta; (9) is not. (3) is compatible with the existence of non-present times; (9) is not. Further, since Merricks is our authority when formulating the view, (9) is also distinct from (4) and (5)

Presentism with non-present objects
Recall our starting point, the conception of presentism as: (1) Only present objects exist.
Thus far, all statements of presentism deny that non-present objects exist. But there are dissenting versions. E.g., Orilia (2016) articulates a view, described as a 'moderate' version of presentism, according to which there exist no non-present events, but there exist non-present times and non-present objects. Thus: (10) Only present events (and objects), non-present times, and past (and perhaps future) objects exist.
Orilia thinks that (10) has much to recommend it and argues that it can help to address problems that make trouble for other versions of presentism (2016: p. 590).
Orilia is not alone in allowing that presentism is consistent with non-present objects. Smith (2002) defends 'degree presentism', according to which existence admits of degree (2002: pp. 119-20). The present moment is the moment at which objects exist maximally (to the greatest degree); non-present objects, or objects at non-present moments, exist to a lesser degree. Thus: (11) Only present objects exist maximally; non-present objects exist less than maximally.
It is also important for us to note that (11) marks a significant departure from Smith's (1993) earlier view, according to which presentism is the view that: '[Every] possibly true sentence includes presentness in its semantic content. This implies that all possibly true tenseless sentences, including all sentences that seem to have a timeless semantic content (such as "Two plus two equals four") include components that ascribe a presentness-involving property to something. ' (1993: p. v) This presentism unites a semantic claim (every true sentence includes presentness in its semantic content) and a metaphysical claim (every such sentence ascribes a presentness-involving property to something). Thus, every property is a present property. (Smith adopts a state-of-affairs metaphysic and treats presentness as an aspect of each state of affairs.) Here we have Smith's early characterisation of presentism: (12) Every possibly true sentence includes presentness in its semantic content and ascribes presentness to its subject.
Prima facie, (12) is very different from any characterisation of presentism reviewed thus far.
Other statements of presentism also posit the existence of non-present objects. On Baron's (2015) 'priority presentism', only present entities exist fundamentally, non-present entities are grounded in (or depend upon) some aspect of the present. Hence: (13) Only present entities exist fundamentally; non-present entities exist derivatively.
Priority presentism accepts the derivative existence of non-present objects and, therefore, it is distinct from (1), (4), and (9). It is also different from other versions of presentism that accept non-present objects, i.e., (10) and (11), because of the relationship of metaphysical dependence (grounding) between non-present objects and the present. With (10), past objects do not depend upon the present for their existence, and there is no suggestion that past objects are derivative existents. Equally, with (11), though past objects exist to a lesser degree than present objects, there is no relationship of diachronic dependence at work.
Whilst our aim is not to offer an exhaustive survey of all different characterisations of presentism, there are two further versions of presentism worth mentioning. Fiocco (2007: pp. 191-2) equates presentism with a claim about the metaphysical importance of this moment, the now. (14) There is something metaphysically distinctive (qualitative or ontological) about the now.
For Fiocco, presentism is sufficiently broad that any view that conjoins (14) with further metaphysical theses 'as may be necessary for a substantive account of the nature of temporal reality' counts as a version of presentism (2007: p. 192).
Another position worthy of attention is Fine's (2005) 'factive presentism' which can be introduced by first describing aspects of his non-standard tense realism. Here is Fine: '[Reality] will be fragmentary. Certain of the facts constituting reality will 'cohere' and some will not. Any fact is plausibly taken to belong to a 'fragment' or maximally coherent collection of facts; and so reality will divide up into a number of different but possibly over-lapping fragments' (2005: p. 281) The facts contained within the whole of reality will fail to cohere. However, there are various 'fragments' of reality and within each fragment we find only consistent facts. We may thus suppose that one fragment includes the tensed facts that: there were dinosaurs, the UK is a part of the EU, there will be Mars outposts, etc. Another fragment includes the tensed facts that: there were dinosaurs, the UK is not a part of the EU, etc. These fragments are partially overlapping in that they both contain the same tensed fact (that there were dinosaurs), but the fragments themselves are distinct. (Though an informal sketch, this gives a sense of the view.) Fine then says the following of his 'tense-theoretic realism': 'Tense-theoretic realism, by contrast, is the view that reality is tensed. Reality contains tensed facts … Tense theoretic realism is, in its own way, a form of presentism; for, in so far as reality comprises tense facts, it must be oriented towards the present. We might therefore call it factive as opposed to ontic presentism.' (2005: p. 299) Thus, we have Fine's 'factive presentism' 6 : (15) Past, present, and future facts exist, but are all oriented towards the present.**** 6 Fine treats factive presentism as compatible with the rejection of ontic presentism, viz. 'the view that only presently existing things are 'real'' (2005: p. 298): 'It is readily possible for a factive presentist not to be an ontic presentist. Indeed, he may endorse a full ontology of things past, present, and future' (2005: p. 299). Some, e.g., Torrengo & Iaquinto (2019), have suggested that factive presentism is not presentism, unless conjoined with ontic presentism; then it is presentism as it is 'ordinarily understood' (2019: p. 185). For a discussion of 'fragmentalist' presentism, inspired by Fine, see Iaquinto (2019).
Despite the fact that (10)-(15) contradict earlier statements, presentism is seen to be sufficiently flexible to count each view as a version of presentism. We will not introduce further variants, though there are others that could be included. It suffices for our purpose to have these views on the table for discussion.

No such thing as presentism?
The taxonomy in Sect. 3 establishes that there are many views flying under the 'presentism' banner and that many of these views are incompatible. But more can be said. We believe that the term 'presentist' is now merely idiomatic; a term so elastic as to simply advert to a collection of views that share no salient core. There is no shared set of features that these competing views have in common and in virtue of which we can call them 'presentist'. That being so, there is no core that Cameron, Deasy, et al. can attempt to preserve with their metaphilosophical exploits.
The crux of the problem is that there is no relevant thesis, no core issue, that unites the views. For instance, according to each of (1)-(15), must it be the case that there exist no non-present objects? No. Some require it; others do not. We can dig into the heart of this issue to illustrate the diversity of 'presentist' views.
First, note that some views explicitly reject non-present objects; others accept them. Compare (1), viz. 'only present objects exist', and (10), viz. 'only present events and objects, non-present times, and past objects exist': on (1), no non-present objects exist; on (10), some non-present objects exist. Similar remarks go for (11)-(15), each of which is consistent with the existence of non-present objects.
Even some of (1)-(9) seem to permit non-present objects in one way or another. Consider (2), viz. 'only present (physical/concrete) objects exist'. On this view, for all x, if x is a physical/concrete object, then x is a present. Thus, (2) is compatible with the existence of non-present abstract objects (e.g., timeless abstracta) or nonpresent 'ex-concrete' objects (cf. Williamson 2002). Furthermore, consider versions of presentism specified in terms of what is real rather than what exists, e.g., (5), viz. 'only the present time is real'. On these views, the present is the real. But we must assume that only the real exists to conclude that (it must be the case that) there exist no non-present objects. By themselves, the views are compatible with the existence, though not the reality, of non-present objects. The core of presentism cannot therefore consist in the claim that (e.g.) there exist no non-present objects.
Does the core lie elsewhere? According to the views described, must there (for instance) be a present time and must there only be a present time? No. Consider (9): proponents of this view are explicit that they do not think that there are times-there is nothing that is the present time (Merricks 2007: p. 125). Further, times (if they exist) would be either points, fusions or sets of objects related by a simultaneity relation, or else substances, and nothing about most of the views described entails such things exist. Certainly, none of (1), (2), (6)-(8), (11)-(13), and (15) are such that they require the existence of times. By contrast, each of (3)-(5), (10), and (14) require the existence of a present time, since they make explicit mention of times. And, perhaps most pressing, even eternalists (and growing block theorists, etc.) could say that there must exist a present time. Thus, a putative core of presentism cannot consist solely in a commitment to a present time.
Of course, there are other issues we could probe, but none seem likely to help. 7 We could ask 'does the view entail that there are propositions that change truthvalue over time?' But that will not help get to a core of presentism, since most A theorists will answer 'yes' the metaphilosophical debate in question seeks presentism, not merely an A theory. We could ask 'does the view posit fundamental tense operators?' But it is not clear that this helps either, for most A-theorists will answer 'yes' and, as before, we want presentism, not merely an A theory. Three of the views see presentism as a claim about what it is to exist or to be real; others deny it. We could go on, but to what end? We cannot prove a negative; we cannot demonstrate that there is, categorically, no shared feature, F, such that any theory that commits to F is presentism. But we do not need to set the bar so high. As we see it, matters are clear enough. Wherever we look, there is no shortage of disagreement on answers to 7 Though something of a diversion, the following points are germane to seeing why we conclude that presentism has no core. (1) ['Only present objects exist'] requires that all objects are present; this thesis denies the existence of non-present objects, makes no commitments to real non-existents, and makes no claim about what it is to exist (or to be real).
(2) ['Only present (physical/concrete) objects exist'] shares the commitments of (1), except that (2) (6) is not a view about what it is to exist. (7) ['Only present objects are real'] shares the commitments of (5), except that (7) is not committed to the existence of times, for the same reason that (1) and (2) are not committed to times. (8) ['The present is real, the past is unreal (in one sense), and the future is unreal (in another sense)'] makes no claims about times or abstracta; (8) is consistent with the existence (not the reality) of past and future objects. (9) ['Existence is presence'] is a claim about what it is to exist; (9) entails that there are no non-present times. And, as noted, one background commitment of (9) is that there is nothing that is the present time. Further, (9) is inconsistent with the existence of nonpresent (atemporal or 'timeless') abstracta; abstracta, if they exist, must be present. (10) ['Only present events and objects, non-present times, and past objects exist'] entails that there exists a present time and (10) is committed to the existence of other times and non-present objects; (10) is also compatible with the existence of non-present abstracta and it makes no claims about what it is to exist. (11) ['Only present objects exist maximally; non-present objects exist less than maximally'] shares some of the commitments of (10), except that (11) is a claim about what it is to exist-existence is a matter of degree and to exist presently is to be maximally existent-and (11) need not be committed to the existence of times (for familiar reasons). (12) ['Every possibly true sentence includes presentness in its semantic content and ascribes presentness to its subject'] is inconsistent with the existence of non-present abstracta; abstracta, if they exist, must be present. (13) ['Only present entities exist fundamentally; non-present entities exist derivatively'] entails that there exist non-present entities; (13) is compatible with the existence of nonpresent abstracta and it makes no claims about what it is to exist. (14) ['There is something metaphysically distinctive (qualitative or ontological) about the now'] entails that there must be a present time, i.e., something that is 'the now', and it is compatible with the existence of non-present abstracta. (15) ['Past, present, and future facts exist, but are all oriented towards the present'] entails that there exist non-present facts (and, so, non-present entities); (15) is compatible with the existence of non-present abstracta and it makes no claims about what it is to exist. core questions. This is the evidence that shows that there is no family of views with shared characteristics worthy of the name 'presentism'. There is no single salient thesis upon which these views-all described as presentism-can agree. What is the common core of presentism? So far as we can tell, there is none. 8 To return to our earlier point, this makes trouble for those who think there is a core of presentism that can be captured. E.g., Deasy (2017) argues that presentism should be understood as A-theoretic transientism: the view that there is an absolute present, and sometimes, something begins to exist and sometimes, something ceases to exist (2017: p. 391). But, of the versions of presentism surveyed, this characterisation is not consistent with any of the following: (11) Only present objects exist maximally; non-present objects exist less than maximally.
According to (11), no object ever begins to exist or ceases to exist. All objects always exist to some degree. (12) Every possibly true sentence includes presentness in its semantic content and ascribes presentness to its subject.
There is no reason to expect that (12) requires that any entity begins to exist or ceases to exist. (13) Only presenExistence Presentismt entities exist fundamentally; non-present entities exist derivatively.
No object needs to come into or go out of existence; only its relative fundamentality must change. (14) There is something metaphysically distinctive (qualitative or ontological) about the now.
That there is something (anything) distinctive about the now does not require that any entity begins to exist or ceases to exist. (15) Past, present, and future facts exist, but are all oriented towards the present.
Such a view appears to require that nothing begins to exist and nothing ceases to exist (i.e., permanentism rather than transientism).
Thus, there is clear water between Deasy's transientism and views defended by self-described presentists. Notably, this kind of transientism also seems out of step with views that render presentism a claim about what it is to exist (cf. Tallant 2019), rather than a view about whether sometimes things begin to exist. One is a debate about the nature of existence, the other is about when things exist. It seems hard to capture the one (existence presentism) with the other (transientism).
Thus, as we have made vivid, if there is no core of presentism, then there is no core presentist insight that Cameron, Correia and Rosencrantz, Deasy, inter alia, can try to capture in their metaphilosophical discussions.

X is not presentism, strictly speaking
A response: clearly, not all of the views outlined in our survey are, strictly speaking, versions of presentism. Our anticipated opponent may argue that there is a core to presentism, contrary to appearances; it simply turns out that not all of the views described as presentism are really presentism. There is, thus, an easy road to saying that those versions of presentism-the 'right' ones-are the ones that those invested in trying to capture the core of presentism are attempting to analyse.
One who objects in this way may even suggest that some of the proponents of views that violate the natural spirit of presentism are aware of this fact. To give this argument teeth, here is Baron (2015) on his 'priority presentism', i.e., our (13)-'only present entities exist fundamentally; non-present entities exist derivatively': 'Serious presentists maintain that only present entities exist, possess properties and serve as the relata in relations (Bergmann, 1999) … [Priority presentism], however, is new and is not a claim that serious presentists would accept. So priority presentism is not a version of serious presentism and thus, arguably, not a version of presentism, strictly speaking. Still, the spirit of presentism remains, given the ontological import of the now, which is, after all, carrying most of the ontological load by grounding the rest of the world across time.' (2015: p. 330) For Baron, (13) is not 'a version of presentism, strictly speaking' (ibid.). Let us take Baron to be our opponent. In making this judgement about (13), Baron seems to think that there is a core of presentism, and what is at the core of presentism is a claim about whether there exist any non-present objects and whether there exist non-present times. The presentist's core insight is that, put simply, there are none of either. Since (13) rejects that insight, it is not a version of presentism (strictly speaking). 9 Let us interrogate that claim. To support that (13) is not a version of presentism, Baron cites only Bergmann (1999) by way of evidence that the presentist is committed to the existence of only present entities. That is some evidence, of course. But, as we have seen, there is considerable disagreement in the literature about whether a presentist must believe that only present entities exist; Smith (2002), Fine (2005), Fiocco (2007), and Orilia (2016) disagree. And, indeed, Bergmann is cited explicitly as a 'serious presentist' and this 'serious presentism' (introduced by analogy with 'serious actualism' in modal metaphysics; cf. Plantinga 1983: p. 4) is not understood as equivalent to (mere) presentism without further argument. There is serious presentism and there is non-serious presentism (cf. Inman 2012); both are treated as versions of presentism.

The answer is clear
This leads to a related concern. We suspect that the reader may be responding in a similar way to our anticipated opponent. Perhaps you believe that some of the views described are not versions of presentism and that it is obvious which ones. Perhaps, like the reader, Deasy et al. have a good sense of what the core really is. We all know what presentism is at heart-so goes the thought-and, consequently, our argument is no good. The challenge is that our argument fails to respect those intuitions.
To this, we respond as we do to Baron. We may all have our preferred sense of what presentism is. But, problematically, that sense is not universal (as shown above). Indeed, the term 'presentism' has so elastic as to cover views that are mutually incompatible and to include views that have no shared core. And with no shared core there is no core insight of presentism over which Deasy et al. can be arguing.
Of course, we have our own prejudices. There are number of views described above that we do not think of as being presentism (at least, not really). But it is hard to see how that can be relevant. It is hard to see why to take seriously any individual sense of what-it-is-to-be-presentist over another. The philosophers mentioned above, and the referees and editors scrutinising their work, are happy enough that the presentist tent is big enough to fit all-comers. We can call all these views 'presentist' if we want; there is no harm in it, just so long as we remember that the term 'presentism' does not denote any theoretical core and that it is merely a name for a group of similar but disjointed views. 10 But, of course, that renders it impossible for Deasy et al. to have a coherent target in view.
To make the point stark, we borrow from Cameron (2016), who asserts in response to Deasy: 'if anyone is a presentist, Zimmerman is' (2016: p. 20) But, we ask: is that Zimmerman (1996) or (2011)? The former, not the latter, describes presentism as a claim about existence: 'to be present just is to be real or to exist ' (1996: p. 117). The latter, not the former, describes presentism as a claim about where in the 'cosmic jell-o' of space-time we locate objects (only at the present) (2011: p. 200). It is not a claim about existence. If to be present is to exist, as the early-Zimmerman puts it, there cannot exist past times or cosmic jell-o. The core of presentism remains elusive. Not even appeal to the authority of Zimmerman helps us here.

Presentism, physicalism, and metaphysical privilege
Another response: there is a core of presentism, but it is more general than we have supposed. To unpack this response, consider the case of physicalism in the philosophy of mind (see Stoljar 2017). There are many formulations of physicalism and multiple physicalist doctrines, but some are incompatible (i.e., they make incompatible claims, have incompatible commitments, etc.). And, for some physicalist doctrines, there is no widespread agreement (amongst physicalists) about which qualifies as physicalism. Nevertheless, there is a core insight behind physicalism; namely, that what is physical enjoys some metaphysical privilege with respect to what is non-physical. Although we can define 'physical' in different ways, and we can interpret the 'metaphysical privilege' differently, there is a core. Here our opponent replies that something analogous is available to presentism. The core of presentism, according to our opponent, is the claim that what is present enjoys some metaphysical privilege with respect to what is non-present. 11 But this cannot be correct. At least, if this is the core of presentism, then there is a more substantial issue with the taxonomy of views in the philosophy of time. If the core of presentism is merely that what is present enjoys some metaphysical privilege, then the growing block theory and the moving spotlight theory of time would qualify as versions of presentism. Growing block theory states that past and present entities exist, whereas future entities do not exist. And, according to Tooley (1997), 'the central idea underlying this view is that the passage of time involves events, or states of affairs, becoming actual, with the present … being the point at which that happens ' (1997: p. 27). For growing block theorists, the present is the latest moment of existence and the locus of becoming. All of this certainly seems to give the present some metaphysical privilege. Similarly, moving spotlight theory states that past, present, and future entities exist, and that a characteristic or property of 'presentness' moves (in some sense) across times. As Broad (1923) puts it: '[what] is illuminated is the present, what has been illuminated is the past, and what has not yet been illuminated is the future ' (1923: p. 59). Once again, this certainly seems to give the present some metaphysical privilege. However, growing block theorists and moving spotlight theorists do not take themselves to be offering a version of presentism (see, e.g., Tooley 2012, Cameron 2016.

Historical precedent
We have suggested that it would be problematic for us to rule out any of (1)-(15) as a version of presentism merely on the basis of our own prejudice. And, because of this, that there is no core of presentism that we can identify and over which the likes of Cameron, Deasy, etc. can be arguing.
One might however, pursue a different response. Though methodologically fallible, we might suppose that the view that has best claim to being presentism is that which most closely mirrors presentism as it was introduced into the literature. To be sure, such practice is of limited value. The mere fact that a view was introduced in some way need not say anything about how it is now understood. Nonetheless, if there is some striking connection between presentism-as-it-was introduced and one of the statements above, then that may give some reason to prefer that statement. All one has to do to deploy this approach is to review the first statement of presentism. Could it be that over which Deasy etc. are arguing?
No. It is common to see Prior described as a presentist (e.g., Sider 1999: p. 325, Smith 2002: p. 125, Lewis 2004, inter alia), though Prior does not use the term himself. But is Prior a presentist, strictly speaking? To answer this question, let us reiterate Prior's statement of his view: 'Before directly discussing the notion of the present, I want to discuss the notion of the real. These two concepts are closely connected; indeed on my view they are one and the same concept, and the present simply is the real considered in relation to two particular species of unreality, namely the past and the future. ' (1970: p. 245; our italics) What is immediately striking is that this view is not the same as any other. No other version of presentism amounts to the claim that 'the present is the real' or that 'the present' and 'the real' pick out the very same concept. So, if we look to Prior to settle the question of what is presentism, we find that none of the other views described would be regarded as presentist, for none of them (e.g.) identify the concept of the present with the concept of the real. (See Jakobsen 2011 for discussion of Prior.) Rather than appealing to Prior, we might instead look to the first mention of or attempt to define 'presentism' in the contemporary literature. But, once again, matters are unclear. Adams (1986) is the first to use the term in print, so far as we know, but he uses the term in a way that suggests it was already common currency. Here is Adams: 'A reduction is offered by a view that is sometimes called "presentism" by analogy with "actualism." As the actualist holds that there are no merely possible things, but only things that actually exist, so the presentist holds that there are no merely past or future things, but only things that exist now. For presentism, 'exists' in its sole primitive sense is a one-place predicate equivalent to 'actually exists now', and the presentist's primitive quantifiers range only over things that actually exist now. ' (1986: p. 321; our italics) What Adams calls presentism is similar to the object-definitions of presentism with which we began Sect. 3.1, i.e. 'only present (physical/concrete) objects exist'.
Adams introduces the view 'that is sometimes called "presentism"' (ibid.) without saying by whom such a view is so-called. Whilst there is scope for educated guesswork, it only complicates matters. To find the 'source' of presentism in those contemporary with Adams we may look to Mark Hinchliff, David Lewis, or Quentin Smith. Hinchliff's doctoral thesis (A Defense of Presentism 1988) was in progress when Adams (1986) was published. Hinchliff's initial characterisation of presentism is consistent with Adams's: '[the] presentist believes only presently existing things exist ' (1988: p. 3). However, per our remarks in Sect. 3.3, Hinchliff defends a Meinongian presentism; only present objects exist, but there are non-present objects. This is not Adams's presentism.
Some (e.g., Craig 1998: p. 125) point to Lewis (1986) as introducing presentism in his discussion of temporary intrinsics (1986: pp. 202-4). Though Lewis does not use the label 'presentism', he introduces and rejects the following view as a solution to the problem: 'the only intrinsic properties of a thing are those it has at the present moment. Other times are like false stories ' (1986: p. 204). Once again, this is not Adams's presentism. Indeed, even Craig, who points to this as an example of the 'metaphysics of presentism', describes Lewis's characterisation as 'deliciously tendentious ' (1998: p. 126;cf. Ingram 2019: pp. 51-52).
Finally, Smith (1993) uses the label 'presentism' and, according to a biographical note at the outset, started work on the project in 1983 (1993: p. vi). However, as discussed in Sect. 3.4, Smith treats presentism as the view that every possibly true sentence includes presentness in its semantic content and ascribes presentness to its subject. And, to be sure, this view is also not Adams's presentism.
Thus, Adams's view is not that of Hinchliff, Lewis, or Smith. Add to these Prior's statement of his view, regarded by many as presentism, and it seems we have no agreement as to what is presentism-and no set of shared features that allows us to identify a core. Indeed, we can already see in this early work some of the variation present in the contemporary debate. That being so, an appeal to historical authority is not fertile ground for Cameron, Deasy, etc., if they are to locate a core of presentism over which to debate.

A final worry
Finally, one might worry that much of this discussion proves the opposite of what we claim, i.e., that there is something that putative presentists try to describe and yet fail to agree on. This presents an interesting challenge, one that we disambiguate in two ways-on one disambiguation the claim that there is something that putative presents try to describe is correct, but we do not think that either disambiguation undermines our project.
On the first disambiguation, there is a way that the world is. For the sake of argument, we assume that it is captured wholly by the claim that 'only present objects exist' (but any of the above accounts would serve). In this case, there is something that putative presentists try to describe, a particular metaphysical structure of the world. It just so happens that putative presentists have not all settled on how this is to be captured.
On this disambiguation, it is correct to assert that there is something (the structure of reality) that putative presentists try to describe and fail to agree upon. Nonetheless, that is no threat to our project. Recall, our goal here is to adjudicate on a metaphilosophical dispute-how views under the 'presentism' banner are united. When we say (in Sect. 2) that presentism has no core, we mean that there is nothing distinctive, no philosophically interesting, unifying feature, in virtue of which it is correct to call these views 'presentist'. This claim is unaffected by the structure of reality being some particular way-at least, so far as we can tell. All that happens on this disambiguation is that one camp has the correct account of how the world is. But that is, we think, not to answer the question of what it is in virtue of which each of the views described above can be described as 'presentist'.
On a second disambiguation of the worry, we can set aside the structure of reality. On this disambiguation, there is something that putative presentists have in common when they try to describe their view, they just fail to agree on what that 'something' is. In other words, there is a theory, T, that is presentism, and that presentists collectively are trying (though failing) to collectively capture.
Nonetheless, and to return to our wider concern, it remains the case that each of the views we have outlined above, though each are described as 'presentist', have no shared feature in virtue of which we can describe them as presentist. To be sure, each may be trying to reach T (though, we submit, we have no positive reason to think that this is the case). Let us be charitable and assume that this is so. But that the authors of the above views are trying to reach T does not seem to be germane to our project. Again, when we say (in Sect. 2) that 'presentism has no core', we mean that there is nothing distinctive, no unifying feature of the views themselves, in virtue of which it is correct to call them 'presentist'. A desire to capture T on the part of their exponents does not seem to undermine that contention.

Concluding remarks
Since there is no single view that Cameron, Correia and Rosenkranz, Deasy, etc. can try to capture, their metaphilosophical project is empty. There is still good work that can be done. We can either use the logical machinery introduced by Williamson or not, and we can argue about whether it is appropriate to do so. But we cannot treat capturing the core of presentism as the goal-some methodological pay-off for using the apparatus. There is no core; there can be no pay-off.
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