1. Could Omissions Be Identical with Events We Already Take to Exist?

Of the philosophers who think omissions are events, they typically proceed by arguing that omissions are identical with events that we already take to exist. This is a good strategy insofar as it reduces omissions to normal, physical events, and it follows the more generally accepted metaphysical strategy of reducing items in a problematic category to items in an unproblematic category. However, I show below that a challenge for this kind of view is accounting for just how varied the situations are in which we omit.

An early version of this kind of view can be found in in Brand (Reference Brand1971), where he identifies omissions with the actions we perform in order to omit. Brand gives the example, ‘I can refrain from raising my hand by putting it in my pocket, by sitting on it, or by keeping it at my side’ (49–50). This clearly will not do, however, because we frequently take ourselves to be omitting (and to be responsible for those omissions) even when we do not perform certain actions as a means of omitting (Clarke [Reference Clarke2014: 14] makes this point). Instead of meeting my friend for lunch, I may go to the movies, but it need not be that my going to the movies is the means by which I omit to meet my friend.

We might instead adopt the more popular view that our omissions are identical with the actions we perform as we are omitting. Vermazen (Reference Davidson1985) and Varzi (Reference Varzi, Castellani and Quitterer2007) both advocate for this view. Rather than thinking of omission as negative actions, we might instead think that we have omitted when our actions can be given a negative description. We might, for example, alternatively describe a certain action as ‘sitting still’ or as ‘not moving’. The idea, then, is that there is nothing extra and spooky about my not moving; rather, the act called ‘not moving’ is just another way to describe my action of ‘sitting still’. In the case of my omission to meet my friend for lunch, we may think that I perform one action we call ‘going to the movies’ that can also be negatively described as ‘not meeting my friend’. This view gets us the positive result that our omissions will no longer seem to be paradoxical, since we are no longer saying that our not acting is an action. Instead, our omissions are just regular actions that admit of a negative description.

This can also be taken as a natural extension of the Davidsonian view of actions, first given by Davidson (Reference Davidson1971/2011). (This is why Vermazen [Reference Vermazen, Vermazen and Hintikka1985] proposed it and Davidson [Reference Davidson, Vermazen and Hintikka1985] himself accepted it as a nice extension, later in the same volume.) Though we speak as if we, with one motion, are able to perform sometimes many actions, we might think that these are just different ways of describing one and the same body movement. On this view, each of our actions is identical with a body movement caused in the right way by our mental states. Given this kind of view, we can easily think that omissions just are certain movements that we perform that can be negatively described in terms of what we are not doing at the time.

Though this view does have omissions as events for which we can be responsible, it runs into a number of problems (some of which are raised by Clarke [Reference Clarke2014: 24–27]). The claim is that the event that is my omission to meet my friend for lunch just is my body movements as I go to the movies. However, we can straightaway see a number of apparent differences between my omission and my movements, and we can use Leibniz's Law to infer their distinctness from these differences.

Although I happened to go to the movies while I was omitting to meet my friend for lunch, I could have done any number of different things (and moved in any number of different ways). In these cases, however, it would seem that I was nevertheless still performing the same omission. Similarly, we can imagine cases where one moves in just the same way and yet does not omit. Perhaps the exact same movements would land me either at the movies or at lunch with my friend. Then even if in the actual world I go to the movies and omit to my meet friend, I could have moved the same way and not omitted. So, there are apparent modal differences between my omission and my movements as I omit—my omission and movements come apart in different possible worlds.

Our omissions also appear to have different causes and effects from the movements with which they are supposed to be identical. I might have omitted to meet my friend for the reason that I did not want to see my friend, while I might have gone to the movies separately for the reason that it looked like it was going to be a good movie. It would be wrong to say that the reason I decided to omit caused me to go to the movies, since my desire to avoid my friend is unrelated to my desire to see the movie; and it would be wrong to say that my reason for going to the movies caused me to omit to meet my friend, since my desire to see the movie may not have even entered my mind until after I had decided to omit to meet my friend. Concerning their effects, my omission may cause my friend to become upset at me, taking it as an expression of my lack of care for the friendship, while my going to the movies may cause me to reflect on the themes of the movie.

Finally, we might think our omissions and movements can come apart in the properties they instantiate. Though my omission to meet my friend may cost me her friendship, it cost me no money. So my omission has the property of being free. Going to the movies, however, may have the property of costing nine dollars. Even if I spend the very same amount I would have spent at lunch on the movies, it seems wrong to say that it cost me nine dollars to omit. My omission saved me money that I instead spent at the movies.

Now, there is a lot to say about these kinds of arguments. They could be given more in depth and persuasively, and there are ways for a Davidsonian to respond to each of them. (See Payton [Reference Payton2018] for a recent defense of a Davidsonian view of omissions that addresses these modal and causal arguments.) This should not be surprising. A large literature in the metaphysics of ordinary objects has been generated around these kinds of arguments in the statute/lump case. As in that case, a Davidsonian could answer at least the modal objections by taking on controversial views of transworld identity, perhaps by accepting a counterpart theory for events. (See Kaiserman [Reference Kaiserman2017] for a discussion of issues relevant to and advantages of a counterpart theory for events.) This will provide the resources to say that if I were to have taken a nap while omitted to meet my friend rather than going to movies, then it really would have been a different omission.

Even if we were to accept the Davidsonian view, however, we would still need to explain our contradictory intuitions concerning the location of omissions, and we would need to say why there are not too many omissions. I find the objections to the Davidsonian view persuasive, so, in section 2, I outline an alternative view that is able to avoid the above objections before considering the other issues with omissions as events. The broader point to bring out is that the objections to the Davidsonian view do not speak specifically against omissions as events, and a satisfactory view of omissions as events can survive rejecting it.

2. Omissions as Sui Generis, Fine-Grained Events

It is reasonable to expect there to be a view of omissions as events even if the Davidsonian view is incorrect. Although there are many objections to the Davidsonian account of omissions, the ones given have more to do with Davidson's more general view of action than with the supposedly problematic nature of omissions. Davidson identifies all actions with mere movements of the body, even those involving complex social practices, such as hailing a cab or voting ‘yea’ on a proposition or moving a pawn in chess. Just as in the case of omissions, it can seem that not all of our actions should be identified with mere movements of the body. Although I may hail a cab by raising my arm, my cab-hailing may seem distinct from my arm-raising. And the arguments we would use against this view of action in general will be just the same Leibniz's Law arguments that I showed could be given to the Davidsonian view of omissions.

A rejection of the Davidsonian view of action does not lead us to reject the existence of all actions that cannot easily be identified with body movements. Instead, such a rejection motivates us to search for a more fine-grained account of events that allows us to distinguish those actions we take to exist as events distinct from body movements. Similarly, that the Davidsonian view cannot convincingly be extended to omissions is a problem for the Davidsonian view, not for the existence of omissions.

In order to see how it could be appropriate to think of omissions as events, I suggest taking on a particular account of events and seeing how omissions could count as events on that particular account. For example, consider how we would think about omissions on the fine-grained account of events given in Jaegwon Kim's ‘Events as Property Exemplifications’ (Reference Kim, Brand and Walton1976). There, Kim claims that events can be understood as the exemplification of properties by subjects at a particular time. On his account, events can be referred to as object/property possession/time triples. For example, the sentence ‘The light went on at dusk’ picks out the event of the light's turning on where the object is the light bulb, the property exemplified is the turning on of the light, and the time is dusk.

Kim's account goes well with a view of properties as universals; however, a fine-grained account of events need not accept this particular view of properties. Bennett (Reference Bennett1988) offers an alternative to Kim's view on which events are a matter of the instantiation of properties as tropes. I remain agnostic about this debate here, since I do not think a proponent of omissions as events must accept (or cannot accept) one of the views. For the purposes of staying in the Kimian framework, I continue to speak of the exemplification of properties.

Now, consider how the account might apply to omissions. Take the case of my omitting to pick up my friend from the airport yesterday. This is an event of which I am the object; I exemplify the property of omitting to pick up my friend from the airport; and this occurred on the particular day that is now yesterday. I discuss in section 3 how to think about this property of omitting, but for now it is helpful just to see how omissions would be construed on this account of events. They are to be understood in terms of objects’ exemplifying certain properties. Just as an agent may exemplify the property of raising her arm, the agent may exemplify the property of omitting to raise her arm if she decides not to raise it. Prima facie, it will be no more difficult to have omissions as events than it is to have more run-of-the-mill actions as events.

Further, we can see how this view avoids all of the problems given for the Davidsonian view. Each of those problems stemmed from the claim that omissions really are identical with some movement of the body or some action the agent is performing while she is omitting, but omissions on a Kimian view of events will not be identical with an agent's body movements. So omissions will certainly have different modal properties or have different causes and effects. But this does not make omissions into very mysterious things as events. Like body movements or other actions, they will involve the exemplification of properties by agents at times. As I discuss below, it may still be that omissions on this view heavily depend on what the agent is doing or how the agent is moving as she omits. So, this view may ultimately be quite similar to Davidson's view. It merely involves accepting a view of events that is fine-grained enough to circumvent the objections to the Davidsonian view.

One problem with this approach is that the Kimian view of events is controversial in a way that that might be thought to spell trouble for omissions. It is often argued that the Kimian view is too permissive in what it counts as events—Bennett (Reference Bennett1988) offers a thorough critique of Kim's view along these lines. For Kim, every property that is exemplified at a given time by a subject picks out a distinct event, but this can lead to our accepting far more events than we might have thought plausible. For example, we might say that I wave to you or that I wave to you energetically or that I wave to you enthusiastically. Regardless of how I describe my wave, it seems like a single event, but Kim will count at least three events because of these three distinct descriptions that pick out three distinct properties. As a different kind of example, we might say that right now I exemplify the property of being identical with myself, or of being one person, but it would be very odd to say that there is an event of my being identical with myself or of being a single person that is occurring right now. So Kim allows for a staggering plentitude of events. This is worrisome if we want to show that omissions are events, because now we might think that one of the ways that Kim's view is too permissive is that it reifies omissions.

Kim's view of events may be too permissive. However, it is not in virtue of how fine-grained it is that it allows for omissions. I have suggested adopting Kim's view of events to avoid the difficulties of Davidson's view, but Davidson himself allowed for omissions while accepting a much more coarse-grained view of events (Reference Davidson1985/2011). According to his preferred view, first given by Quine (Reference Quine1960), events are individuated by the spatio-temporal regions, and an event just is everything that happens within a particular region. Accepting this view would make us more likely to say that omissions just are body movements purely because they occur at the same place at the same time.

As with a counterpart theory of events, I think this Quinean view of events is implausible. I mention it only to illustrate that it is not because Kim's view is so fine-grained that it allows for omissions. The broader point is that omissions are not the kinds of things to be ruled out or in depending on how finely we individuate events; rather, this question only determines whether it is appropriate to think of omissions as sui generis events or as identical with body movements. We should no more expect our account of events to rule out omissions than we should expect it to rule out energetic waving.

There are plausible restrictions to Kim's account that we might make without being driven to a view as coarse-grained as Davidson's, but our task here is to legitimize the idea that omissions are best understood as events, not to deliver the correct account of events. So, let us take for granted the Kimian view. Instead, we can recognize that the better challenge to omissions as events is more a matter of what omissions on this view of events would involve.

3. Omissions and Negative Properties

The view of omissions as fine-grained events avoids the objections to the Davidsonian view, and it also tells us exactly what they are (they are exemplifications of properties by subjects at times). However, those who think that omissions cannot be events may instead object to the kinds of properties that omissions would require. We might think that if omissions were events, then they would have to involve the exemplification of certain negative properties, and we might have reasons for thinking that negative properties do not exist. (I leave to the side the further possibility that omissions involve ordinary, positive properties being related to objects via a relation of ‘non-instantiation’. See Clarke [Reference Clarke2014: 40–44] for a discussion of and challenges to different options for how to think about omissions and property instantiation.)

If I omit to meet you for lunch, then the omission will seem to be a matter of my exemplifying the property of not-meeting. Or, if I refrain from eating a cookie, then that omission will be a matter of my exemplifying the property of not-eating. However, while we would accept positive properties such as being the eating of a cookie, it may sound as though there is no property that is a not-eating, for instance. To answer this concern, below in this section, I show why omissive properties in fact are not negative. (It may even be that there are no negative properties, though I remain agnostic on this question. Even if it were shown that omissive properties had to be negative though, they still would surely be non-fundamental properties. See Zangwill [Reference Zangwill2011] for a defense of the claim that negative properties could exist as long as they are non-fundamental.) Following this, I engage with the reasons for why we might think that they are negative, and I discuss what omissive properties are if not negative.

First, we should recognize that there is a distinction to be made between omissions and instances of mere inaction or non-doings/failings. It is hard to support the claim that my not eating a cookie or my failing to eat a cookie would not involve the exemplification of negative properties if they were events (an event of being a not-eating, in this case). But my refraining or abstaining from eating the cookie is not merely my not eating the cookie. Consider the difference between refraining on the one hand and merely failing to do something on the other. It is true to say that George Washington did not come to the meeting last Friday, and it is even true that Washington failed to come to the meeting (even though we would not blame Washington). But Washington certainly did not omit to come or refrain from coming to the meeting. The dead cannot refrain, and in general we think one must be able to do what one omits or refrains from doing in order to be omitting.

(This is part of what can be so appealing about an account on which omissions are possibilia—a matter of what the agent could have done but did not actually do [à la Bernstein Reference Bernstein2014a], as this would explain why there seem to be ability-constraints on omissions. One must be able to do what one is omitting to do, but one obviously does not need to be able to do everything that one merely does not do. What is less appealing about an account of omissions as possibilia, however, is that it will be difficult to see how they can count as causes and effects.)

It may not yet be clear exactly what the difference between omitting and not doing is, but there is one, and we might hope to exploit it to claim that while non-doings would involve negative properties (if they were events), omissions do not. However, perhaps this is not how they differ. We might worry that they differ with respect to whether an agent is involved in the right way, or whether it is an expression of agency, not with respect to their negativity.

To this concern, we should recognize that non-doings are essentially negative—they are about things not done—whereas omissions need not be. Omissions can be very effortful, positive occurrences. Perhaps my refraining from eating the cookies involve a very conscious effort of looking at the ceiling. As another case, perhaps a voter abstains from voting on a measure not by not pushing either a ‘yea’ or ‘nay’ lever, but by pushing a third lever marked ‘abstain’. What makes her action an abstaining from the vote is not a non-doing of hers but a doing of hers, although there is still something that she does not do. I do not think all omissions must be like this and involve omitting by doing some particular action (contra Brand), but that most omissions could be performed by doing something positive suffices to show that they are not essentially negative in the same way that non-doings are.

Instead, I appeal to exactly what the Davidsonian does: there are no ‘negative’ events or properties; rather, omissions are just events that we frequently describe negatively. My refraining from eating a cookie involves the exemplification of the property of refraining. This is not the property of being a not-eating, although my exemplifying the property of refraining can be described as my not eating in this case. Further, it is appropriate for me to appeal to the Davidsonian response, because the view of omissions as sui generis events does not introduce anything essentially negative into the world above the Davidsonian account.

We should remember again just how close my alternative account is to the Davidsonian view. Although this view has many problems, it is not taken to be one of them that it involves anything problematically negative. My view only involves accepting a more fine-grained view of events, so it does not seem to involve introducing anything negative. We simply individuate events based on property exemplification rather than spatio-temporal region, but the same properties would be exemplified regardless. Insofar as the Davidsonian maintains omissive and negative event descriptions and is happy to say that certain movements are omissions, the Davidsonian seems to be committed to all of the same properties that I am.

It is true that the Davidsonian view does not hinge on omissive properties as mine does. So, a Davidsonian could argue that there are alternative truthmakers for the negative descriptions of body movements, rather than accepting omissive properties as those truthmakers. However, a plausible Davidsonian line would be to say that ‘omission’ and ‘movement’ are distinct types (but both equally types), and that they are instantiated in the same token. My view of events merely disagrees that these types are instantiated by the same token, so my view does not involve a commitment to some extra property.

There is still a question, however, of what these properties are. At least Davidson could appeal to a reductive story. Omissions are body movements. I cannot appeal to this, so it is fair to wonder about the nature of omissive properties. If we cannot give some appropriate account of them, then they may still seem negative.

Consider again my abstaining from voting and contrast it with the act of voting. It might be thought to be mysterious just what the property of being an abstaining is. However, I submit that it is no more mysterious than the property of being a voting. For both properties, there are further questions about what they are, what they are like, how we know about them, and how they relate to other things. There is no unique mystery left over for the property of being an abstaining. Just as in the case of my voting, my abstaining will be related in some way to what I do as I abstain (or how I move).

We can also see that the property of being an omission will be extrinsic. Whether an agent performs an intentional omission will depend on certain properties of the agent as well as relevant features of her environment. We cannot intentionally abstain from a vote without having the intention to abstain, nor can we abstain without there being certain regulations and rules in place regarding the voting procedure. This is appropriate, because the properties associated with our non-omissive actions are extrinsic in just the same way. I cannot instantiate the property of voting as an intentional action without having certain antecedent or concurrent mental states, nor can I without voting regulations. So, that omissive properties have these features is what we would expect if they are to be assimilated with other standard action properties. It is appropriate to question the nature of omissive properties, but doing so does not suggest that they are problematically negative.

4. The Location of Omissions

On both the Davidsonian view and my alternative view, omissions have locations. For Davidson, my omission is located just where my body is moving as I omit, because my omission just is my body movement. Matters may seem slightly more complicated on my alternative view, but it delivers the same result. My omission is a matter of my exemplifying the property of omitting at a time. Given the assumption that events are located where the object that exemplifies them is located, omissions are again located with the agents that exemplify them. Events need locations, so it is a point in favor of the view of omissions as events that it shows where they are located; however, there are at least two puzzles about where omissions should be located and why.

One puzzle concerns whether our omissions are located at a part of our body or our whole body. If I am standing in front of a nice car and I refrain from reaching out and touching it with my arm at my side, is my omission by my side with my arm or is it at my whole body? On my view, this will come down to whether we take the object that exemplifies the property of omitting to be me or my arm. And although I may refrain with my arm, it seems that I am the one that refrains, not my arm. So, on my view, omissions will be located with the whole body of the omitting agent, not merely with the part that would be active if the agent were not omitting.

This may seem like an odd result. After all, it is hard to imagine that my omission to touch the car is partially located at the region with my right foot. Nevertheless, there are two things to consider to help us accept this implication. First, while my omission is exactly located with my whole body, the view does not say that part of the omission is exactly located with any particular part of my body. Second, this difficulty is no more a problem for omissions than it is for typical actions. Suppose I do reach out and touch the car. Then we would again be left with the question: Is my touching the car located with my arm or my whole body? And, if the latter, does that mean that my touching the car is partially located with my right foot? It may be that I touch the car with my arm, but it would be odd to locate my touching the car entirely with where my arm touches it, given that this is an action I intentionally perform. I am willing to claim that omissions are exactly located with the omitting agent's whole body, but even if I am wrong, the fact that this is a problem faced for both omissions and actions shows that this location puzzle alone is insufficient to rule out omissions as events. There is a second location puzzle, however, that we might think is more worrisome.

The puzzle is to explain why our omissions are located with us given that we often have strong intuitions that our omissions can be located far from us. Prima facie, it is not clear whether we should think our omissions are always located where we are or whether our omissions are at the place we are omitting to be. For example, I can refrain from meeting my friend for lunch and instead go to the beach, but then it is not clear whether I omit at the beach to be at lunch or whether my omission is at the restaurant, causing my friend's disappointment, though I am far away. Wherever we say my omission is, we are forced to say something problematic. If I can decide to omit and then omit far from where I am located, then how can I control my omission, or how can it depend in any way on what I am doing far from where I am omitting? On the other hand, if I can omit just where I am located, then it's not clear how those omissions can be immediately causing something far from where they are located. So, we are faced with a dilemma.

Given my metaphysical view of omissions, I am committed to grabbing the horn of the dilemma that claims that omissions are always located with their agent. The omission is where the agent is as the agent is omitting, even though the omission is distinct from the agent's body movements. The challenge, then, is to say how our omissions can be causally relevant to events that are far from where they occur and why we are drawn to thinking that they can occur far from us. To answer this, I think we must first recognize that an omission by an agent to be at a certain place results in an absence of the agent from that place.Footnote ¹ It is familiar territory in the philosophy of action to distinguish between an action and the result of that action—for example, we often distinguish the act of raising one's arm from its result, the arm's rising. McCann (Reference McCann1974) spells out the distinction between actions and results, where results of action are understood to be those entities necessary for the act to have occurred, though not sufficient. If we take omissions to be events and a subspecies of our actions (and so, for there to be acts of omission), then we should expect our omissions to have results in just this sense, and I think we should expect their occurrence to result in certain absences.

This of course does not tell us exactly what absences are. According to McCann, the results of actions are themselves events. However, I do not think we must say that absences are events, even if they are the result of omissions. For consistency, I hereafter follow Thomson (Reference Thomson2003) in saying that absences are states of affairs. So, if I omit to pick you up from there airport, then there is a state of affairs of my being absent from the airport. Just what the difference is between events and states of affairs is contentious, and I do not want to be committed here to any particular view of states of affairs. Instead, what is relevant is just that omissions are distinct from absences, and they may not be colocated.

So, to return to my example, my omission stays with me at the beach, while the state of affairs of my absence from lunch is located where I am not. The absence is entailed by my omission, since it is a necessary condition on my so omitting that I am absent from the lunch. (We need not say here exactly where the state of affairs of my absence is located. This will depend on the most plausible view of the location of states of affairs more generally.) As another example, if John omits to water Mary's flowers, then John omits wherever he is, though there is an absence of water in the soil of the plant. Because absences such as these are not identical with our omissions or any of our actions, they may be located far from us (or not located at all) without generating a location problem.

This answer requires the use of an uncontroversial distinction in the philosophy of action, but it also requires the more controversial assumption that absences exist along with omissions. Absences and omissions have many of the same problems, so perhaps if we are satisfied that omissions could exist as events, it is not such a leap to claim that absences may exist as well. Regardless of whether we think it takes more to show that absences would exist along with omissions or whether the fact that we would have to include absences into our ontology is further evidence that omissions do not exist, it is at least interesting to see how absences can be used to help solve this problem for the location of omission.

5. Causation by Omission

Omissions might be thought to be problematic not only for their existence and location, but for the amount of causation that their existence seems to entail. I offered an example of this in the introduction. I may omit to water Jane's flowers, and her flowers die as a result. However, it is also true that for each person, that person also did not water Jane's flowers, and it is true that if they had, the flowers would not have died. If we reify omissions as events, then we may seem to be committed to accepting all of these failures to water as events and as causes of the death of the flowers. Moreover, whereas it seems that I alone am responsible for not watering Jane's flowers, now it will be unclear what separates me as responsible from everyone else that failed to water.

We can immediately start to see our way to a solution by remembering the distinction drawn in section 3 between omissions and instances of mere non-doings. Many people as a matter of fact do not water Jane's flowers, but I am alone in omitting to water the flowers. If we take it to be a requirement of omissions that they be a certain kind of manifestation of our agency (or at least an expression of our attitudes), and we do often use the term this way, then we can see how I can omit to water while the queen does not.

(I leave it open here whether all omissions are actions. Even if we thought that intentional omissions were actions, we may think that unintentional omissions need not be. The standard view is that unintentional actions are intentional under some description, but we can imagine cases where an agent unintentionally omits to do anything without intentionally acting at the time of that omission. We often take ourselves to be responsible for unintentional omissions of this kind, and they often do seem to be manifestations of our agency in so far as they express what we care about, are focused on, or our attitudes. My omitting to pick up my friend from the airport may express a lack of regard for my friend. We take ourselves to be responsible for omissions like this because of what they express about us, not because they are actions. What matters for my purposes here is just that there will still be a difference between unintentionally omitting to do something and merely not doing it.)

This suggestion fits well with the claim from Clarke (Reference Clarke2014: 29–33) that we can advert to some measure of context when considering how to apply the term omission. Though Clarke himself will say that most omissions are absences and do not exist, I could use much of the same story for determining when events of omissions actually occur. In fact, that one must be in the right causal context in order to omit fits very well with the suggestion given below in section 6 about how omissions fit into a causal theory of action.

In the case above, I agreed to water the flowers, and I may have intentionally ensured the draught. My omission is clearly an expression of my agency and so something for which I am responsible. Even so, it is not that the queen of England did omit to water as well but can be excused for so omitting. It is inappropriate to attribute any sort of responsibility in this case to the queen, because the death of the flowers was in no way a reflection of her will or a manifestation of her agency. The queen's omission did not cause the death of the flowers, because the queen did not omit.

Still, the queen did not water the flowers, and we might wonder whether or not the absence of her watering is nevertheless still a cause of the death. What I have said leaves untouched the issue of what we should say about absence causation more generally, but it is with the problem of absence causation that the literature has largely been concerned (Schaffer Reference Schaffer2000; Beebee Reference Beebee, Collins, Hall and Paul2004; McGrath Reference McGrath2005; Dowe Reference Dowe2010; Sartorio Reference Sartorio and Hazlett2010; Bernstein Reference Bernstein2014b). We do accept many causal statements involving absences that are not intentional omissions, and doing so appears to lead to entirely too much absence causation. So we might worry that my view of omissions cannot solve this problem.

Although the challenge of what to say about absence causation is significant, it is not a challenge for my view of omissions. In fact, it is a virtue of the account that it does not require having a settled view about absence causation. Even if we reify absences as well as omissions (as I discussed above in section 4), my view does not take omissions to be a species or type of absence. It is even agnostic concerning the kinds of things that absences are. Given this, we can allow that omissions cause without having to understand this as a special case of absence causation. Regardless of how we think we ought to handle absence causation—and authors in the literature have come up with quite a few ways—it will not influence how we understand what omissions are and how they cause.

Further, my account of omissions does not even require accepting an account of causation that might motivate concerns about absence causation (such as a counterfactual account). Whereas omissions are often given as a case meant to constrain views of causation, if omissions are events, then we can largely be agnostic about the nature of causation. For example, because omissions involve the exemplification of properties, omissions could even be incorporated into the singularist account of causation given in Armstrong (Reference Armstrong and Sankey1999), on which causation is a matter of the instantiation of laws that links properties. Armstrong himself argues that omissions and preventions should not be included among the causal relata on his account (177). However, if I have successfully argued that omissions do involve the exemplification of properties, then it is not clear how to exclude them on this and other productive accounts of causation.

6. Omissions and the Causal Theory of Action

What I have said up to this point has been focused simply on showing how omissions could be events, but this does not show that they will also be actions (or even merely some manifestation of our agency). Even if we can show that our omissions are colocated with our body movements and how they are closely related to those movements, this falls short of demonstrating that omissions/refrainings/abstainings are instances of agency. Doing this would require accepting a particular view of what it takes for something to be an action and showing how omissions satisfy this. In this final section, I sketch one such popular view of action and gesture towards both how omissions can fit into it as well as problems that remain.

Consider the causal theory of action, first given by Davidson (Reference Davidson1963). This influential view holds broadly that all actions are events with the right sort of causal history. According to Davidson's original version of this view, actions are body movements that have been caused by certain mental states (beliefs and desires) in the right sort of way. Of course, every aspect of Davidson's version of the view is controversial. We may think, for example, that actions can be events closely related to body movements without being identical with them (as I suggest at the beginning of section 2). And it is famously difficult to say exactly what ‘the right sort of way’ is for mental states to cause actions. Still, many philosophers of action maintain that some version of the causal theory of action must be right. It is very plausible that actions are actions in virtue of being caused in some way by mental states.

If we accepted a view on which omissions were not events, as most current theorists do, then it would be quite difficult both to accept the causal theory of action and to maintain the intuition that omissions are manifestations of agency of some kind. Of course, there are options. We could claim that omissions are manifestations of our agency but not actions (and so do not need to be captured directly by a theory of action). Alternatively, we could claim that omissions are not events but can still be caused, given a different view of the causal relata.

A more recent route taken by proponents of the causal theory of action has been to suggest how our intention to omit could play some sort of causal role even if there technically is no omission that exists to be caused. Clarke (Reference Clarke2014: ch.3) maintains that although omissions are absences and do not exist, there are facts about our absences. He argues that these facts are entailed by what we do when we omit, and what we do is caused in the right way by our intentions. Shepherd (Reference Shepherd2014) argues that our intentional omissions are typically a matter of our intention's causing a disposition not to perform the act we are omitting. And Buckareff (Reference Buckareff2017) argues that our intentional omissions are a matter of our intention's being a part of the causal process that explains the truth of our not performing the act we are omitting.

Many of the answers given on behalf of the causal theory of action are creative, ontologically parsimonious, and deserve close inspection. Still, if omissions are events, then the answer is alluringly simple: omissions, like other actions, are events that are caused in the right way by the right kinds of mental states. Omissions may be distinctive in that they involve an agent's not doing a certain thing, but they are no different from other actions in so far as they satisfy the same causal criterion.

Of course, a lot has to go right in order for this picture to work. We have to be convinced that omissions are events, and we have to spell out and defend a particular version of the causal theory of action. It may also still be that there are particular challenges to fitting omissions into the causal theory of action. For example, Sartorio (Reference Sartorio2009) claims that there is a causal exclusion problem unique to omissions on the causal theory. Nevertheless, by showing how we can accept omissions on a broadly Kimian view of events, and by showing where we can find them, I hope to have gone part of the way towards fitting omissions into an account of action.