Absence experience in grief

In this paper, I consider the implications of grief for philosophical theorising about absence experience. I argue that whilst some absence experiences that occur in grief might be explained by extant philosophical accounts of absence experience, others need different treatment. I propose that grieving subjects' descriptions of feeling as if the world seems empty or a part of them seems missing can be understood as referring to a distinctive type of absence experience. In these profound absence experiences, I will argue, the absence of a person as a condition on various possibilities is made manifest in the structure of experience over time. Thus, by paying close attention to grief, we can see that even accounts of absence experience that are presented as in competition with one another may not be so, and that to explain all kinds of absence experience we sometimes need to appeal to something overlooked in other accounts, and which is neither straightforwardly perceptual or cognitive. I also suggest that we would have good reason to take such experiences to be part of and not merely psychological effects of grief. If there is any time in a life when we might expect experiences of absence to occur, it is during a period of grieving. After all, grief is a response to loss. Thus, we might hope that a philosophical account of absence experiences will be able to accommodate those that occur in grief. The philosophical debate about absence experience is primarily between perceptual and non-perceptual theorists. Focussing on cases in which a particular entity is saliently missing from the subject's surrounding environment, there has been disagreement about whether one can perceptually experience such an absence or whether instead the absence is experienced in virtue of having some other cognitive

mental state or event.I argue that whilst some of the absence experiences of grief can be accommodated by these accounts, others cannot, namely those "profound" absence experiences that subjects appear to be describing when they say that the world seems empty or a part of them seems missing.I offer and account of these experiences which allow us to take subjects' descriptions of them literally.On this account, we need to appeal not as in extant accounts of absence experience, to the content of the experience or its attitude type, but instead to the structure of the subject's experience over time, which may include various kinds of mental item.Thus, paying close attention to grief is fruitful for understanding absence experience in two ways.Firstly, it suggests that even those accounts of absence experience that are presented as in competition may not be so.Secondly, it reveals the possibility of a kind of absence experience that straddles the perception/cognition divide.
In Section 1, I survey philosophical accounts of absence experience, and in Sections 2 and 3, I consider some experiences that occur in grief that can be explained by some of these accounts.An additional aim of Section 3 is to argue that if we are to take subjects' descriptions of "profound" absences literally, we need an additional account.In Section 4, I offer a structural account of these experiences.I propose that sometimes, the absence of a person as a condition on various possibilities, some of which may be closely related to one's sense of self, shows up in the structure of experience over time.The focus of this paper is on the nature of absence experience rather than the nature of grief (or the nature of emotion more generally).Nevertheless, I end-in Section 5-by noting that on the structural account, profound absence experiences can be considered constituents and not merely effects of grief.

| PERCEIVING (AND OTHERWISE EXPERIENCING) ABSENCES
An absence experience represents or presents something as missing or not present.An experience may be of a negative entity, such as a shadow or a hole (Sorensen, 2008) without being an absence experience.For instance, according to Brian O'Shaughnessy, seeing darkness is not an absence experience.Instead, it is seeing a "presence"the appearance or sensation of darkness-that signifies an absence.(O'Shaughnessy, 2002, p. 335).
The major division amongst philosophical accounts of absence experience is between perceptual and nonperceptual accounts.Perceptual accounts are ones on which some kind of absence is either perceived-i.e., the subject is perceptually related to an absence-or at least perceptually experienced, even if that does not amount to making perceptual contact with an absence. 1 For instance, on Anya Farennikova's mismatch model, the visual experience of a worldly absence such as the absence of one's laptop from the desk consists in "an object-level mismatch" between a template of the relevant object "generated by visual working memory and a percept of the observed stimulus."(Farennikova, 2013, p. 444)  2 The representation of absence that results is properly perceptual, on Farennikova's view, because the process of template matching-or mismatching-she appeals to is sufficiently "low level."(Farennikova, 2013, pp. 448-451).
Clare Mac Cumhaill offers a different perceptual account, the configural account.Her intention is to explain visual perceptual experience of "absential locations": regions of space from which something is absent.Taking inspiration from Sartre's description of the experience of Pierre's absence from a café, Mac Cumhaill's account has two components.First, she argues that Sartre experiences a location (the café) as one from which Pierre is absent due to the way his experience is "configured."Specifically, the café is experienced as "figureless ground"-a background without a foreground.(Mac Cumhaill, 2018, p. 35) Secondly, according to Mac Cumhaill, Sartre's experience coming to have this configuration is explained by his perceptual activity: his looking for Pierre.As a result of looking for and not finding Pierre, what it's like for Sartre to experience the café changes, without any change in the "properties represented by or presented in the experience."(Mac Cumhaill, 2018, p. 42).
Structural-features accounts are a third kind of perceptual account of absence experience.Such accounts target cases in which a category of sensory item such as visible things or sounds is experienced as absent.For example, Matthew Soteriou argues that it is a "relatively invariant structural feature" (Soteriou, 2011, p. 195) of our visual experiences of objects that those objects are seemingly located in a region of space the boundaries of which are determined by our visual sensory limitations. 3In virtue of visual experience having this structure, when there are no visual objects in the region of space, we are aware of the space as empty, namely, of visible things. 4  Cognitive accounts are typically presented as in competition with perceptual accounts: they are offered in order to show that experiences of absence are not perceptual experiences, but experiences of some other kind.For instance, according to O'Shaughnessy's judgement account, what we call "hearing" silence is merely "a special case of coming-toknow of contemporary silence."(O'Shaughnessy, 2002, p. 330) On Martin and Dokic's metacognitive account, the kinds of experience that Farennikova is concerned with are not experiences of absence at all, but metacognitive feelings of surprise.(Martin & Dokic, 2013) On Laura Gow's intellectual seeming account the experiences that perceptual accounts try to explain are absence experiences-rather than merely experiences of surprise-but they are intellectual seemings rather than perceptual experiences.Intellectual seemings are on Gow's view "experiences with propositional content, and a characteristic belief-like or judgement-like phenomenology."(Gow, 2021, p. 9).Some extant non-perceptual accounts appeal to conative or affective rather than cognitive states.These are typically introduced to explain a different range of absence experiences than those addressed by perceptual and cognitive accounts.Andre Abath's desire-frustration model is intended in the first instance to accommodate some absence experiences which other views overlook. 5Such experiences are, Abath argues, "a matter of subjects having their desires for something to be present (in a somewhat defined location in space or not) frustrated by the world."(Abath, 2019, p. 57) Tom Roberts describes a kind of emotional absence experience: an emotional numbness in which one is aware of one's failure to exhibit the kinds of bodily feelings and dispositions that characterise emotion.(Roberts, 2019) Finally, Matthew Ratcliffe describes a particularly profound example of affective absence experience: that of the absence of hope.(Ratcliffe, 2013).

| ABSENCE EXPERIENCE IN GRIEF (I): FRUSTRATED DESIRES AND EMPTY CHAIRS
Absence experience is, unsurprisingly, common in grief.Bereavement, to which grief is paradigmatically a prolonged emotional and more broadly cognitive response, means, above all else, the absence of a loved one from the world. 6  In a 2002 study, 85 bereaved subjects were asked to write an essay in response to the question "what does the death of your loved one mean to you?"The most common theme-found in 81% of the essays-was called by the authors "feeling the absence."(Gamino et al., 2002) Can philosophical accounts of absence experience explain any of those that might occur in grief?
Conative and affective accounts of absence experience are sometimes explicitly presented as relevant to grief.
Abath argues that his desire-frustration account can explain how the deceased might be experienced as absent, even when they were rarely physically present to one, in life.(Abath, 2019, p. 55) The son whose deceased Father travelled a lot but was available by phone has a frustrated desire that he be available in that accustomed way and thus experiences his absence even though not from a place in his near environment.Roberts suggests that emotional numbness sometimes characterises grief.
Whilst they are not offered with grief in mind, perceptual accounts offer plausible analyses of other experiences that a bereaved subject may undergo.For example, when a person with whom you shared a home dies, you may have expectations that they will be present at certain places, such as in their favourite chair or in a certain room.One subject reports expecting her deceased loved one to appear "especially…in the bathroom when I'm brushing my teeth." 7The mismatch model could explain an absence experience occurring in this context: this subject's expectation would generate a visual template of her loved one in working memory, yielding an experience of their absence from the bathroom as a result of a mismatch between that template and the stimulus.Furthermore, there are accounts of grief on which literally searching or looking for the deceased is a typical phase of bereavement, for example, on Bowlby's attachment-based theory of grief, 8 and according to Parkes and Prigerson.(Parkes & Prigerson, 2010, p. 56) If that is correct, then we can expect the regions where the search takes place to sometimes be experienced as absential locations in the way Mac Cumhaill describes.
There is also potential for perceptual accounts of absence experience to explain some experiences that are described as ones of the presence of the deceased.As Thomas Fuchs has argued, experiences of both absence and presence are common in grief, and the dividing line between these two is not always clear.In particular, the experience of presence is frequently ambiguous.Certainly, whilst vivid bereavement hallucinations can occur, the experience of the presence of the deceased is often very unlike that of the physical presence of a living person.It is fleeting and, as he puts it, is not so much of their presence, as their "as if" presence.(Fuchs, 2018)  9 In her discussion of Farennikova's model, Mac Cumhaill suggests that we might appeal to visual templates to explain a difficult-toexpress aspect of some absence experiences.Pierre's absence, Sartre says, "haunts" the café-there is a "flickering" aspect of phenomenological character that may, she suggests, be explained by the activation of the template.(Mac Cumhaill, 2018, p. 45) We might speculate that some ambiguous experiences of the presence of the deceased can also be categorised as ones of "haunting absence", thus capturing their inherent ambiguity. 10  On the face of it then, philosophical accounts of absence experience-affective and perceptual-can be harnessed to explain some experiences that may occur during grief.Furthermore, the perceptual accounts that we have discussed here seem able to offer plausible treatments of different kinds of absence experience in grief, as well as perhaps some experiences of presence.In the next section, I will mention some other cases that seem more plausibly accounted for by cognitive accounts.I will also argue that attention to grief suggests that there may be a kind of absence experience that no extant account can explain.

| ABSENCE EXPERIENCE IN GRIEF (II): EMPTY WORLDS, DIMINISHED SELVES (AND AN ABSENT BIRTHDAY GREETING)
In the empirical study mentioned above, "feeling the absence" was broken down into a number of subcategories: yearning for, missing and longing for the deceased; lost companionship; a sense of lost dreams that was future directed; a sense of emptiness; loss or diminishing of the self and finality: an overwhelming sense of the permanence of the loss.(Gamino et al., 2002) I want to focus on two of these subcategories which I will call "profound absence experiences."The first is the category of experiences of the world in general seeming "empty" or "hollow."(Fuchs, 2018, p. 48) According to Allan Koster, "feelings of emptiness are among the sources of suffering that are most consistently reported by persons who have been bereaved of an intimate other."(Koster, 2020, p. 126) The second category is that of experiences of absence in or of oneself-sometimes described as a part of oneself being missing.As has been noted, some bereaved subjects compare the experience to one of amputation.(Ratcliffe, 2019) (Parkes, 1975).
Before addressing whether these experiences can be accommodated by the accounts surveyed in Section 1, we should pause to consider whether what is reported are really absence experiences at all.One issue is the relationship between absence and emptiness.Emptiness is not naturally thought of as the absence of a particular thing (object, event or property) or type of thing.Rather, to say that something, such as a room, is empty is to report the absence of any thing from that room.However, as Dretske points out, what counts as a thing in the context of attributions of emptiness is context dependent.A warehouse is in most contexts empty even if it contains dust and air, and an empty freezer may contain ice deposits.(Dretske, 1981, p. 366) This is something to which we'll return later.The point, for now, is that emptiness is a species of absence, namely, absence of any thing, where what counts as a thing is context dependent.Thus, an experience of emptiness would be a species of absence experience.
Another reason for caution in relation to these cases is that it is possible that what subjects are giving voice to in describing what we might take to be absence experiences, is something else altogether.As in the comparison with amputation, a subject's aim may be to "convey the profundity and painfulness of loss" (Ratcliffe, 2019, p. 78), rather than to be taken literally.In fact, this is a concern that might be raised in relation to other difficult-to-understand descriptions of grief, such as Denise Riley's description of time seeming to stop for her after the death of her son.(Riley, 2012) Part of what needs to be done to establish whether such descriptions are merely metaphorical is to consider whether there is any plausible account on which they can be taken literally.In the case that is our focus heredescriptions apparently of profound absence experiences-I will argue that a literal construal is both possible and plausible.That is, I will argue that we can acknowledge and explain the occurrence of experiences of emptiness and self-diminishment in grief.To do so, however, we clearly need another account, other than those surveyed above.Take, first, the perceptual accounts.As we saw, they seem well suited to explain some of the absence experiences that occur in grief and maybe even some experiences of presence.But the experience of the world as empty cannot be understood as the result of a mismatch between a perceptual template and environmental stimuli, as on the mismatch account.It is not plausible that there is a perceptual template that could play the required role.Likewise for the absence of a part of the self.It is not plausible that this describes, for instance, the experience of a literal part of the body that one expects to find, nor that we have perceptual templates for non-bodily self-parts.Neither does the configural account seem up to the task of explaining such experiences.It might be urged that such an account can explain the experience of emptiness: for those who describe their experience in this way, the whole world is, like Sartre's café, a figureless ground.However, given the role that perceptual activity plays in the configural account, this would require that the grieving subject who experiences the world as empty is literally looking everywhere for the bereaved in the same way one might look for a friend one is expecting to meet.It is not at all obvious that this is the right thing to say, even if we accept that searching for the deceased is sometimes an aspect of the bereaved subject's mental life.When Sartre goes to the cafe, it is with the explicit intention and thus anticipation of meeting Pierre there.In contrast, when someone is very entwined with one's life as a spouse, for example, may be, this does not just or even primarily consist in always anticipating their presence: we will turn to what it does (partly) consist in later, in Section 4. Thus, it does not seem right to say that the bereaved subject will be looking for the deceased everywhere in the same way that Sartre, on Mac Cumhaill's view, looks for Pierre in the café.And, even if this approach had some traction in explaining the experience of the world as empty, it clearly does not in the case of the experience of a part of oneself being missing: there is no reason to believe that bereaved subjects ever engage in perceptual activity that could be described as looking for a part of themselves.Finally, the structural-features accounts do not seem likely to explain profound absence experiences.They explain how awareness of our sensory limitations in a modality allows us to experience kinds of sensory item (visible things, sounds and odours) as absent.
Without further testimonial evidence to the contrary, it does not seem reasonable to believe that descriptions apparently of profound absence experience ever pick out experiences such as these.
What about the non-perceptual accounts of absence experience?Could they explain the profound absence experiences of grief?Let us start with affective accounts.It might be suggested that the only absence experiences that the language of profound absence experience is used by subjects to pick out are experiences of emotional numbness and hopelessness.To accept that suggestion would be to deny that these subjects' descriptions are to be taken literally, as referring to experiences of worldly emptiness and self-diminishment.As I noted above, we would have to accept some such non-literal interpretation if there were no experiences that meet the subjects' descriptions, taken literally.I will be arguing in the next section there are experiences of worldly emptiness and self-diminishment to which these descriptions might instead apply.
It is implausible that subjects are describing what are really experiences of surprise, which is, recall, how the metacognitive account explains putative absence experiences."Surprise" just does not seem like the right description for something so profound ("will you look at that, a bit of me has gone!").Gow's intellectual-seeming account might seem more promising, since the content an intellectual seeming can have is quite unrestricted.For that reason, there may be some absence experiences in grief that it is well placed to explain.To see this, recall that Abath's desire-frustration model does a good job of explaining experiences in which an experienced absence does not appear to be in one's vicinity and which are therefore not to be explained by perceptual accounts.But there may also be non-localised absence experiences where it is not especially plausible to say a desire is involved and thus to which Abath's account would not extend.For example, to adapt one of Gow's own examples, one might experience the absence of a Facebook birthday greeting from a deceased friend, even though one had not wanted such a greeting.
Because of the relative lack of restrictions on the content of intellectual seemings, Gow's account would be well suited to explain such experiences.This (to digress a little from my main line of argument in this section) provides further support for the suggestion that accounts of absence experience that are typically understood as in competition may not be so.In the previous section, we saw that different perceptual accounts may be required if we are to acknowledge differences between experiences of localised absences (and maybe presences) that can occur in grief.We have now seen that though perceptual and cognitive accounts are typically presented as in competition, at least one cognitive account may be required if we are to explain all of the non-localised experiences of absence that may occur.Of course, I have not established that there is no possibility of someone offering a unified account of all these cases.Nevertheless, viewed through the lens of grief, it is not clear why such a unified account is to be preferred to a more pluralistic approach that can respect the differences between different absence experiences.
Returning now to the profound absence experiences, we might think that given the lack of restrictions on the content that intellectual seemings can have, provided, we can identify the right contents for the profound absence experiences of grief, we could take these to be the contents of intellectual seemings.But this is where the problem for an intellectual-seeming account of these experiences would lie: in identifying the appropriate contents.Specifically, there are no propositions that seem to capture the experiences accurately.As Koster puts it, "feelings of emptiness are inherently fuzzy" (Koster, 2020, p. 126), and the same seems to be true of the experience of a part of the self as missing.As one subject puts it "it is hard to put into words how devastating it feels and how alone and empty.
Words do not explain the feeling.You are torn apart totally." 11The same problem-that of identifying the appropriate content-would bedevil a desire-frustration account of our profound absence experiences, for that would require propositional articulation of the content of the frustrated desire.It would also and for the same reason be an objection to the suggestion that the profound absence experiences of grief are beliefs or judgements.
An obvious-seeming response to this problem is to deny the "fuzziness" in question, by pointing out that subjects express these experiences clearly enough, in propositions such as "the world feels empty and hollow", and "it feels as if a part of me is missing."But comparison with another case shows us how far these descriptions are from giving us the accuracy conditions, and thus the propositional content, of the experiences in question.Take "the bag feels empty", said whilst rooting about in it.Here, taking the report at face value gives us the accuracy conditions and thus the content of the experience.If there is no thing in the bag, then the experience is accurate.The contextdependence of attributions of emptiness mentioned above does add complication.But (without further specification of the context) "the bag feels empty" might reasonably be taken to mean that it is empty of things that can be felt: if there is air in the bag, for example, that would not make the experience inaccurate.Thus, even taking into account the context dependence of attributions of emptiness, we have a good sense of what the accuracy conditions in this case would be and thus of the content of an experience of the emptiness of the bag.But in "the world feels empty" and "it feels as if a part of me is missing" this is not true.These utterances do not when taken at face value give us accuracy conditions for the experiences described.For instance, and as we said above, it is wholly unclear what the world would have to be empty of for the first kind of experience to be accurate.
Can this problem for an intellectual-seeming (or other propositional) account of the profound absence experiences of grief be overcome?Perhaps, what is causing the problem is a mistaken way of thinking about what it is to have an intellectual seeming, namely that this is an "all or nothing" thing.Eric Schwitzgebel has argued that belief is not to be thought of in that way.That is because, on his view, to believe that p is to meet the stereotype for that belief, where the stereotype is a cluster of dispositions.(Schwitzgebel, 2002, p. 251) This makes room for "inbetween belief"-meeting the stereotype to some degree, by having some but not all of the dispositions.(Schwitzgebel, 2010) Perhaps, in principle, a similar account of intellectual seemings could be provided.That is, maybe the "fuzziness" or ambiguity of it seeming that the world is empty or a part of oneself missing can be explained by in-between versions of these propositional attitudes.However, the ambiguity that an account like Schwitzgebel's buys us is the wrong kind of ambiguity.For what seems to be needed is not a way of accommodating having an attitude such as belief that p or intellectual seeming that p only partially or to some degree, but an account that allows for an experience of something messy, ambiguous and difficult to express.It does not look then as if thinking of intellectual seemings as things that can be had to a degree will help us to make Gow's intellectualseeming account of absence experience fit to explain the profound absence experiences of grief.

| A STRUCTURAL ACCOUNT OF THE PROFOUND ABSENCE EXPERIENCES OF GRIEF
Attention to grief, I have suggested, makes it plausible that accounts of absence experience typically presented as in competition are not so.Attention to grief also demonstrates that an additional account is needed, to explain the profound absence experiences of grief which subjects describe as ones of emptiness or diminished selfhood.Without such an account, we would have to conclude that such descriptions cannot be taken literally.In this section, I piece together and defend what I will call a structural account of these absence experiences.Two things are distinctive about this account.First, it does not explain its target experiences in terms either of a distinctive kind of content or a distinctive kind of attitude type.Instead, profound absence experiences are explained by appeal to the shape or structure of the stream of experience over time.The second distinctive feature of the structural account arises from the first.As we saw in Section 1, accounts of absence experience have been either perceptual or cognitive (and sometimes conative or affective).Since the stream of experience over time is made of a variety of experience types, profound absence experiences straddle this divide.Thus, we need to recognise a kind of absence experience that is neither perceptual nor cognitive.
As a first step in explaining the structural account, observe that in life, a person can be an object of many kinds of experience: you can perceive them, have occurrent beliefs and desires in which they figure in the content and have emotions about them, for example.But in addition, someone can "show up" in your experience of other things that are not them.They can do this in the way in which they make other things possible.This phenomenon is most easily illustrated not by established relationships, but by examples in which someone begins to make a difference to a life.Consider, for example, this description of the effect that the child Eppie has on her adoptive Father Silas Marner, in George Eliot's novel Silas Marner: The Weaver of Raveloe.
…as the weeks grew to months, the child created fresh…links between his life and the lives from which he had hitherto shrunk continually into narrower isolation…The gold had kept his thoughts in an everrepeated circle, leading to nothing beyond itself, but Eppie was an object compacted of changes and hopes that forced his thoughts onward and carried them far away from their old eager pacing towards the same blank limit-carried them away to the new things that would come with the coming years…and made him look for images of that time in the ties and charities that bound together the families of his neighbours…Silas began to look for the once familiar herbs again and as the leaves, with their unchanged outline and markings, lay on his palm, there was a sense of crowding remembrances…As the child's mind was growing into knowledge, his mind was growing into memory: as her life unfolded, his soul, long stupefied in a cold narrow prison, was unfolding too.(Eliot, 1861, pp. 206-7).
Eppie makes a number of things possible to the previously miserable and isolated Marner: thinking hopefully about the future, establishing friendly relationships with others and seeing his neighbours in a new and positive light, noticing things in the world familiar from his painful past and being able to think about that past less fearfully.And she does not just initiate these possibilities, setting them in motion.Eppie's presence to Marner sustains these possibilities, ensuring that they continue to be possibilities for him.This is of course a fictional example and may well be unusual in the truly transformative effect that Eppie has on Marner.But in many often less dramatic ways, the people with whom our lives are entwined make for and sustain possibilities, and in that way, show up in our experience in a way that is quite different to simply having a belief about them, perceiving them, having expectations about their presence or looking for them in particular places.

Philosophers of grief have recognised implications of this kind of experience of others for understanding what it
is like to grieve, in particular, experiences of the presence-rather than the absence-of a person after they have died.
For example, Merleau-Ponty suggested that experiences of the presence of deceased loved ones can be understood as analogous to the experience of a phantom limb: in each case, one experiences an illusory presence in virtue of the world still seeming to include the possibilities that depended on the limb or the loved one.(Merleau-Ponty, 1945/2012) Matthew Ratcliffe has suggested that sensed-presence experiences that are not specific to a sensory modality are especially suited to being explained in this way.(Ratcliffe, 2021).
My concern here is of course with experiences of absence rather than of presence.I want to argue that the profound absence experiences of grief can be understood as experiences of the absence of a person as a condition on possibilities.Ratcliffe also implies that the possibilities that are made for and sustained by a person might play a role in experiencing their absence.Questioning the phenomenological plausibility of Merleau-Ponty's analogy between sensed presence experiences and phantom limbs, he writes: Preserving those aspects of the practically configured world that implicate the deceased would also dispose us towards anticipating her appearance and, consequently, confronting her absence.(Ratcliffe, 2020, p. 659).
Though suggestive, this remark does not of course amount to an account of absence experience that is clearly differentiated from those considered above.Neither is it clear how it would apply to the profound absence experiences that are our concern here.For that, we need to answer three questions.
Question 1: How do such experiences occur?Question 3: How can such experiences amount to ones of emptiness or diminished selfhood?Question 2: What is the nature of these experiences?
In the rest of this section, I will answer these questions.
Let us begin with question 1.To give a sense of what it would be to answer this question, recall that according to the mismatch model, perceptual experiences of absence occur due to a mismatch between a perceptual template and incoming stimuli.According to the configural account, perceptual experiences of absence (specifically of absential locations) occur due to actively looking for something in some location such that the location comes to be experienced as a figureless ground.To answer question 1, we need to know how experiences of the absence of a person as a condition on possibilities occur: what is the occurrence of these experiences due to?It is a well-known feature of grief that it takes some time for a bereaved subject to fully acknowledge their loss, for it to "sink in." 12 Furthermore, it is generally recognised that a bereaved person in whom sinking in is incomplete will have, to some extent, the same habits of thought, preparedness and unpreparedness to act in certain ways or to have certain experiences, that they had before their loved one died. 13These aspects of the subject's mental life are as I will put it, "checked" by the world in which the loved one is no longer present.This is how experiences of the absence of a person as a condition on possibilities occur or what the occurrence of these experiences are due to.I will first illustrate this point with some examples, and then say more about the "checking" they involve.Suppose that Amy's husband Ben has died.
Case 1: Ben and Amy always went to the supermarket together and were in the habit of dividing up the tasks this involved.Ben pushed the trolley, Amy held the list and scanned the items at the checkout.Ben reminded Amy to look at the list and packed the bags.So, when they went together to the supermarket, Amy would, for example, think, behave, form intentions and attend in habitual ways that presupposed Ben's presence and participation.In various ways, Ben was a condition on the possibility of a shopping trip occurring and figured in the rather mundane experience of shopping as such-not that it was particularly salient to Amy that Ben was experienced as a condition in that way.Now, Ben dies.Amy knows this of course: if asked whether Ben is alive, she would say, 'no'.But, since the loss has yet to fully sink in, she still has many of the habits of thought and action that she had before she died.These habitual ways of acting and thinking will be "checked" in the sense that their progress will be blocked or brought to a halt or redirected.For instance, Amy may easily lapse into her habitual inattentiveness to the shopping list.This inattentiveness will now be checked by the world in that, in Ben's absence, it gets in the way of getting the shopping done.The experiential disruption that results from checks of this kind over the course of the trip can be described as the manifesting in experience the absence of Ben as a condition on the possibility of carrying out this mundane task or carrying it out in the effortless way she previously did.
Case 2: When Amy and Ben went to parties, they would typically spend most of the time speaking to other people, often separately.But an astute observer would have noticed that they were alert to one another in various ways.
Were it the case that one got into a conversational impasse or found themselves alone, the other would turn up by their side.Likewise, they would attend to whether the other had a full glass, had tried the most interesting snacks, had seen something amusing or noteworthy in the room.It was never agreed between the two that this is how they would behave nor were they especially aware of so doing-it is just what they habitually did.And as a result, for Amy, Ben figured in experience as a condition on the possibility of her comfortable enjoyment of a social occasion.
When Amy goes to a social gathering after Ben dies, she finds herself attending, behaving and perceiving in ways that presuppose all these little services and activities they performed for and with one another.An ugly painting prompts an intention to point it out to Ben, she does not think to fill her own glass, and she struggles to maintain the conversations that she starts without his interjections.Ben's absence is felt then in the overall, conflicted, awkward, checked flow of her experience at the party: his absence, that is, as a condition on the possibility of her enjoying the party, feeling at home there, conversing easily with others.
Though these cases are imaginary, testimonies provided by bereaved subjects when asked about what makes them especially aware of the person's absence can be understood in a similar way.One, for example, answers by describing a kind of "constant hijacking", that "brings me to my knees."Another notes that they are especially aware of the absence of their partner "when the kids are home because we then revert back to routines we had when [he] was around."A third mentions "constant reminders of things done together now being done alone." 14  I have described what happens to a bereaved subject's habitual ways of acting, thinking and so on as "checking."This is not supposed to be a technical notion: something is said in normal speech to be "checked" when its progress is halted, as when we stretch out an arm in the dark and encounter an obstacle.According to A. D. Smith (Smith, 2002), a checking of literal movement through space (which he calls the "Anstoss") is central to the sense of touch: it is because tactile perception involves a checking of bodily movement that it is an experience of encountering a "foreign body."(Smith, 2002, p. 154) What is "checked" in grief, however, are not only bodily movements but activities both physical and mental and habitual ways of experiencing and thinking too.Where such things proceed in a way that still presupposes the presence or participation of the deceased, the absence of the person "checks" their progress as an obstacle checks the movement of an arm through space.This has something in common with an aspect of Havi Carel's notion of "bodily doubt."According to Carel, when we are in good health, we have an "ongoing, tacit, certainty about our bodies."(Carel, 2013, p. 179) This bodily certainty is disrupted in serious illness, giving rise to the experience of bodily doubt, in which the "subtle feeling of 'I can' that pervades our actions", and a corresponding sense of "possiblity and freedom" is eroded.Now, one way in which normal experience is changed in bodily doubt is in a loss of "continuity."As Carel puts it, "the characteristic smoothness of everyday routines is disrupted…the normal flow of everyday activities is halted."(Carel, 2013, p. 188) Likewise, the previous 'smoothness' of experience is disrupted when the bereaved subject finds themselves checked by the world.As we have seen in the case of touch, the experience of checking can constitute an experience of that which one is checked by.Smith's Anstoss constitutes an experience of the object the presence of which checks one's movement.The checking that disrupts the smoothness or continuity of the bereaved subject's experience constitutes an experience of the absence of the person who has died as a condition on some possibility or possibilities.
Corresponding to this account of how such experiences occur, should be a story about how they might cease to come about.As we have seen, what is "checked" by the world are a bereaved subject's habitual ways of acting, thinking and experiencing that still presuppose the presence or participation of the deceased.These are preserved in that the loss they have suffered has yet to be fully acknowledged.Over time though, a grieving subject will come to acknowledge their loss, which means in part that the habitual ways of acting, thinking and experiencing that presupposed the presence or participation of the deceased will be lost.As a result, the subject will no longer find themselves checked and so will no longer experience the absence of the person as a condition on the relevant possibilities.For example, in case 1 above, as loss of Ben sinks in, Amy may lose her previously habitual patterns of (in)attention when at the supermarket and so will not find herself 'checked' there as she did before.Thus, she will no longer experience Ben's absence as a condition on the possibility of a successful shopping trip.I will also suggest below, in Section 5, that these experiences may themselves play a role in facilitating the acknowledgement of loss.
Next, question 2. How can such experiences amount to ones of emptiness or diminished selfhood?I have proposed that a person's absence as a condition on various possibilities can be experienced in grief in various "checks" they receive.These checks can be numerous, as can the kinds of possibilities involved.Over time, I suggest, the experience of numerous and varied checks might be what subjects are picking out when they say that the world seems empty to them.The absence of the person as a condition on a potentially very wide range of possibilities is experienced and thus, the loved one's absence seems to be, as C.S. Lewis put it, "like the sky, spread over everything."(Lewis, 1994, p. 11) It might be objected that even when someone who has died was very integral to the life of the bereaved, that which they made possible will not be so extensive that their loss will amount to the world feeling empty. 15In response, recall the point made above that the truth of "x is empty" is in a certain sense contextdependent.That is, whilst for something to be empty is for it to contain no things, what counts as a thing varies with context.A room may be described as empty following a thorough burglary despite the fact that the furniture remains: everything that matters, as we might put it, has gone.An empty warehouse might contain dust, strewn packing material, even a forklift truck or two and still be empty because what counts as a 'thing' in this case is the sort of item that the warehouse is used to store.Similarly, for the experience of a person's absence as a condition on various possibilities to amount to one of emptiness, we need only allow that there can be a context in which the presence of the deceased, including the possibilities they initiate and sustain, are what is relevant.One potential way to single out such a context in grief is by appealing to the Dual Process Model of grief, according to which the grieving subject oscillates between periods of loss-and restoration orientation.(Stroebe & Schut, 1999) In a period of loss-orientation, there is "concentration on, and dealing with, processing of some aspect of the loss experience itself, most particularly, with respect to the deceased person."(Stroebe & Schut, 1999, p. 212) When this is the context in which the grieving subject finds themselves, the wide-ranging experience of lost possibilities we have described can be an experience of the world as emptied: as containing no relevant thing-as in the burglary case, nothing that matters.
The account can also explain some experiences that subjects describe as ones in which a part of themselves is felt to be missing.Where what was made possible by a loved one was something central to one's self-conception, their absence as a condition on such a possibility can leave the subject feeling diminished, aetiolated.There is room for this in both of our cases above-suppose it was part of Amy's self-conception that she is sociable, good at parties.Or that she is competent in everyday tasks.Then, it is easy to see why the various checks she receives from the world in cases 1 and 2 could amount to a feeling of diminished selfhood: she experiences the absence of an aspect of who she is that is part of her identity.Where a loved one was previously a condition on much of that which constituted one's identity, the feeling of diminished selfhood might be very wide ranging.As one subject put it, "Without him I am nothing and no one."(Gamino et al., 2002, p. 802) Nevertheless, I do not wish to claim, as Koster does, that experiences of worldly emptiness always amount to experiences of diminished selfhood.On his view, in the absence of their "intimate other", the bereaved subject feels less familiar with themselves because of the impact that the loss has on the things in the world that would previously have sustained this sense of self-familiarity.(Koster, 2020) It is consistent with what I have argued here that some of the ways in which the bereaved subject experiences the absence of their loved one as a possibility, is on the possibility of feeling at home in the world and thus familiar with themselves.However, I do not need or want to commit to these being the only possibilities at stake.And, more generally, neither do I want to suggest that whenever the bereaved subject experiences the loss of a possibility previously sustained by the deceased, they experience a part of themselves as missing.Even if Cholbi is correct that grief is invariably for those with whom we have "identity constituting relationships" (Cholbi, 2017, p. 99) not every possibility previously sustained by someone who we have lost will be central to our self-conception.For instance, Amy might have thought of herself as sociable and friendly, but not as especially competent at everyday tasks and thus feel diminished by her experience at the party in case 2, but not by her trip to the supermarket in case 1.
Finally, question 3. What is the nature of these experiences of the absence of a person as a condition on possibilities?Unlike the other accounts of absence experience, the structural account does not explain its target experiences (the profound absence experiences of grief) by appealing to a particular attitude or experience type.For example, the perceptual accounts all explain experiences of absence as perceivings, and the cognitive accounts as types of cognitive state such as intellectual seemings, judgings or metacognitive states.On the structural account, there is no such attitude or experience type that characterises the absence experiences of grief.This can be seen from the examples we have discussed.It is not, for example, only the normal flow of Amy's perceptual experiences that are disrupted in cases 1 and 2, nor her cognitive experiences.Instead, in these cases, Amy's habitual ways of thinking, behaving, forming intentions and attending to her environment are amongst the things that are checked.
Over time, these various checks might amount to an experience she would describe as one of emptiness: a profound absence experience.Thus, if there is a mental kind implicated in this kind of absence experience it is only "stretch of the stream of experience over time", where this is something constitutively varied-made up of various experience types-and thus not really a kind at all.In particular, this stretch of the stream of experience is not itself either a perceptual or a cognitive experience.
Neither, on the structural account, are the profound absence experiences of grief to be understood in terms of the content of an experience.This is something that the structural account has in common with Mac Cumhaill's configural account and the structural-features accounts too.Those perceptual accounts of absence experience, recall, both sought to explain certain kinds of experience of absence in terms of aspects of phenomenal character other than representational content: the configural account appeals to the figure-ground configuration of visual experience, whilst the structural-features account appeals to relatively invariant aspects of perceptual experience in some modality.Similarly, the aspect of phenomenal character that the structural account of the profound absence experiences of grief appeals to is not the content of experience.However, disanalogously to these other cases, the aspects of phenomenal character appealed to by the structural account characterise, as we have seen, a stretch of the constitutively varied stream of experience over time rather than (say) a visual perceptual experience.The emptiness a bereaved subject such as Amy may experience is the result of the non-smooth "shape" or "structure" that this stretch of experience takes on, as she is repeatedly checked.
It is due to the fact that how it seems to the subject is to be explained by the structure and not the content of their experience, that the structural account of the profound absence experiences of grief can explain their difficult to express, "fuzzy" character.This can be seen by means of comparison with the structural-features account of seeing empty space.We can describe what it is like for sight to have its field-like character in more than one way: for instance, we can say that a region of space is experienced or that it seems as if there are places where things go in and out of view or that there are spatial enabling conditions on sight or that sight involves a sense of visual possibilities.It does not matter if these descriptions are not wholly aligned because the phenomenology is not that of the obtaining of a state with propositional content.Thus, there is no unique description (i.e., employing the correct proposition) for us to alight upon and it can feel difficult-in fact, it is difficult-to describe how things seem in the relevant respect.The same is true for the way in which the absence of a person as a condition on possibilities shows up in the structure of experience.What, I suggest, subjects might be trying to describe is not something with a unique description, since it is not a state with propositional content (nor indeed an instance of awareness of a particular object).In particular, though it can be accurately described as an experience of the absence of the person who has died, it is equally an experience of many other things in the world, since the absence is one that shows up in the structure of experience of those other things.
In this section, I have offered an account of the profound absence experiences of grief, which answers the questions we would want such an account to answer.I have argued that we can understand the profound absence experiences of grief as experiences of the absence of a person as a condition on various possibilities, manifest in the structure taken on by a stretch of the stream of experience over time, due to checking.It is plausible that such experiences occur during grief, when-since the loss has yet to be fully acknowledged-the subject still has habits of thought, action and experience that presuppose the participation or presence of the deceased.Hence, we have a way of taking literally the testimonies of those who seemingly report experiences of emptiness and self-diminishment in grief.It is a further question which I will not address here whether, for any such testimony, it should be taken to report this kind of experience.What it is like to grieve varies enormously across time and subjects, and when subjects describe what grieving is like for them at some time, similar language may be used to describe dissimilar experiences.Some testimonies that are couched in the language of profound absence experience may not be intended to be taken literally, and others may pick out absence experiences that are not captured even by the structural account. 16Despite these qualifications, the preceding shows that attention to grief-a context in which absence experience might be expected to occur-draws our attention to an overlooked kind of absence experience, which cannot be characterised as either perceptual or cognitive.
Whilst my aim here has primarily been to consider the implications of grief for philosophical debates about absence experience, I end with some remarks on how the account given here might contribute to the philosophical understanding of grief.

| PROFOUND ABSENCE EXPERIENCE AS PART OF GRIEF
It is a common philosophical view of emotions that they are made up of various mental items such as beliefs, bodily feelings and behaviours.Grief, in particular, seems prone to be understood in this way: when someone is grieving, they may undergo all manner of bodily, cognitive and perceptual experiences and also emotions such as sadness and loneliness.(Ratcliffe, 2017) It is not my aim here to address questions about which if any of these types of components are essential to emotion in general, nor even to grief in particular.But due to the very complexity of the typical grieving subject's experience, it is natural to ask, for any of the experiences they undergo, whether it is really part of grief or merely an effect of it.
One's verdict on this matter depends, of course, on what one takes grief to be.Roberts and Krueger (Roberts & Krueger, 2021) include grief in the family of absence emotions including loneliness, homesickness, envy and nostalgia that have the two-part composition: i. pro-attitude towards x.
ii. awareness that x is absent.
If they are right, then given that the structural account is one on which the profound absence experiences of grief really are absence experiences, then these experiences could, sometimes, be the second component constitutive of grief.Roberts and Krueger's account, that is, explains why any absence experience might be a constituent of grief, and since experiences of the world as empty and part of oneself as missing really are absence experiences on the structural account, they are candidate constituents.More specifically, if in the case of grief, the 'x' in (ii) must be the person who has died, then given that the structural account has it that the profound absence experiences of grief are in fact experiences of the absence of the person (as making other things possible) then, still, these experiences can be constituents of grief rather than effects of it.
However, even if we accept this two-component view as broadly correct, there is of course much else to be said about what grief is, even staying at a fairly high level of abstraction.In particular, it is widely accepted that grief is a process of some kind, (Goldie, 2012) and there is reason to think that the intentional object of grief is not straightforwardly or just the loss of the person who has died.There are various accounts of the grief process, which, like accounts of absence experience, are not always obviously in competition.Let us mention just two, both of which can be understood as explaining what happens when a loss sinks in. 17First, according to Fuchs, the process of grief is one of resolving its central conflict or ambiguity, that is, between the presence and the absence of the deceased.(Fuchs, 2018) Second, Ratcliffe emphasises that it is a mistake to think of grief as an emotional response to a loss that one already recognises.(Ratcliffe, 2017) (Ratcliffe et al., 2021) Rather, the grieving process is one of recognising or accommodating that loss.Furthermore, on Ratcliffe's view, the primary object of grief is not the loss of a person, but a loss of "life possibilities": possibilities that mattered to one's life and in various ways implicated the continued presence of the deceased and the continuation one's relationship with them as it was.
On both these views of the grief process, experiences of absence of the deceased can be considered crucial constituents of that process.It is easy to see how experiences of absence-especially ones with the ambiguous, "fuzzy" nature of those with which we have been concerned here-could be constituents of a process of resolving the felt conflict between presence and absence described by Fuchs.Likewise, as we have seen, the profound absence experiences of grief occur as a result of the fact that-as the loss has yet to sink in-various aspects of the subject's mental life are "checked" by the world.So, these absence experiences display the incompleteness of the grief process as understood by Ratcliffe: the fact that the loss has not yet been fully acknowledged or recognised.Furthermore, they may well play an important role in enabling the unfolding of this process and thus the acknowledgement of loss: as Fuchs says, "grief needs resistance and weight of reality", (Fuchs, 2018, p. 57) which is what we receive when we are "checked."To be checked in this way, and so to feel that the world is empty, and even that one's self is diminished, is to be resisted or received by the world in a way that might make it possible to know-or know in a new way-what one has lost.Finally, as the structural account has it that the profound absence experiences of grief are experiences of the deceased as a condition on possibilities, these are well placed to be understood as the experiences in which we are most open to what we have lost when bereaved, if, as on Ratcliffe's view, grief's primary object is a loss of possibilities.

| CONCLUSION
With just the extant accounts of absence experience before us, we would have to conclude that when bereaved subjects report that the world seems empty to them or that a part of them seems to be missing, they are not to be taken literally.However, the structural account allows us to take these reports literally, as reports of genuine absence experiences, whilst respecting their fuzzy, difficult to express character.It also allows us to see that given some reasonable assumptions about grief, such experiences can be constituents of grief, and constituents that, when they occur, play a central role in its unfolding.Whilst the structural account of profound absence experience can thus play a role in understanding grief, my primary aim has been to show that attention to grief sheds light on the debate over absence experience.Considering the absence experiences that may be had by a grieving subject, suggests that we may need different accounts in order to respect differences between such experiences.Thus, even those accounts that are typically presented as in competition may not be.And, whilst the debate over absence experience has typically pitted perceptual and cognitive accounts against one another, we can also identify a kind of absence experience that straddles this divide.

ACKNOWLEDGEMENTS
I am grateful to Matthew Ratcliffe, Becky Millar, Emily Hughes and Ellie Byrne for comments and advice, and to the AHRC (grant ref.AH/T000066/1) for supporting this work.Thanks also to the virtual audience at an "Experiences" seminar organised by Davide Bordini, and to reviewers for this and other journals for numerous suggestions that have improved the paper.

ORCID
Louise Richardson https://orcid.org/0000-0001-9484-7015ENDNOTES 1 As Laura Gow notes, to say that absences can be perceptually experienced rather than perceived, leaves room for neutrality on the question of the reality of absences and negative ontology more generally.(Gow, 2021, p. 3) See (Tallant, 2017) for recent resistance to negative entities.I do not take a stance on that issue here.