1 It would also be answered affirmatively, obviously, if events could fail to occur at the time at which it in fact occurs (and still occur).

2 If time came to an end at noon last Tuesday, then, though there would have been an interval of time which constituted last Tuesday (it Just would have been a shorter than average Tuesday), there would not have been the interval which in fact consituted last Tuesday, an interval which stretched from a midnight to a midnight.

3 I say, here, ‘in general,’ for if it should turn out that such properties as that of occurring at a certain time are essential properties of events, then there will be one period of time during which an event occurs, namely the time at which it occurs, the occurring during which is essential to that event.

4 I do not wish to make it seem as if this notion, once defined in this way, is unproblematic. For example, what is the minimal duration of an event with scattered temporal parts, like, for example, the World Series? But such problems will not be relevant to present purposes; and so I ,do not propose to try saying anything about them here.

5 Perhaps there is a connection here between these ideas and the idea that no event is logically compelled to occur by what happens at times other than its time of occurrence.

6 Treating the event-designating terms as rigid designators amounts to treating them as always large scoped; so this ‘further’ possibility need not be considered separately.

7 Carter, W.R. in ‘On Transworld Event Identity,’ Philosophical Review, 88 (1979) 443 ff,CrossRefGoogle Scholar employs claims like those in (5) as evidence in favor of the inessentiality thesis. He does not clearly trade on the scope ambiguity inasmuch as he clearly intends the large scope reading; but I believe that what convinces him of the obviousness of his examples is the confusion of the obviously true small scope ver· sions of them with their controversial large scope ones. lnwagen, Peter van in 'Ability and Responsibility,’ Philosophical Review, 87 (1978) 201-24Google Scholar (see, esp., footnote 13), also presents an example, like those in (5), clearly intending to have its event-designating term interpreted as have large scope, as an example of a clear truth which implies the inessentiality thesis. But there is there no argument offered for the truth of the example so interpreted, and so nothing to suggest that a scope fallacy had been committed. Indeed, in correspondence, van lnwagen suggested to me that he intended to offer no argument, but rather simply to exhibit his belief in the inessentiality thesis. In that some correspondence, he, in fact, sketched a direct argument for the inessentiality thesis, an argument which, with his permission, is the subject of the next section of this paper.

8 This is the argument which van lnwagen sketched out to me. There is more, he assured me, that he would say about it.

9 It is worth noting, I believe, that this principle, (6), is not a principle asserting either that events have the causes they in fact have in every possible world which those events occur or that having the causes it in fact has constitutes an individual essence of events. The former of these latter two claims, the principle of the essentiality of an event's effects is the converse of (6), and the latter is the conjunction of (6) and its converse. The converse of (6) was argued against both by me in ‘Some Remarks Concerning the Essentiality of Causes and Effects,’ read at the Pacific Division meetings of the American Philosophical Association, San Francisco, 27 March 1980, and by Carter, op. cit. Carter's and my counterexample to (6)'s converse are virtually the same, though Carter's involves as a premise the inessentiality of an event's time of occurrence while mine does not. Van lnwagen rejects these counterexamples, believing (6)'s converse to be true (see his paper, p. 208), he informs me. But, of course, (6) is a wholly separate principle, though it is not difficult to confuse it with a principle asserting the essentiality of an event's causes.

10 There are, in fact, two ways in which such divergence is possible and compatible with (6). (a) There might be uncaused events which occur in the actual world after the time of the divergence which do not occur in the possible world, or vice versa; and (b) the temporal distance between events after the time of the divergence might be different in the two worlds. But, the kind of divergence which I am claiming to be clearly possible, and incompatible with (6), has nothing to do with either (a) or (b).

11 Since the time at which an event occurs is the shortest period of time during which it occurs, it will follow from this result that no event could have occurred more quickly or more slowly than it in fact occurred (could not have occurred more quickly or more slowly in any possible world than it did in any other possible world in which it occurred). For if an event did, in some possible world, occur more quickly or more slowly than it in fact did, then, in that world, it would have occurred at a time other than the time at which it in fact occurred. Thus, if the argument for the essentiality thesis which I am about to present succeeds, then, though I could have written this paper more quickly than I in fact did, the writing which would then have occurred would not have been the writing which in fact occurred. Small comfort.

12 See my paper, ‘Events,’ Canadian Journal of Philosophy, 9 (1979) 425-60, for a development of this idea.

13 That the causal properties of events are inessential is argued in the papers by Carter and me mentioned in footnote 9.

14 It should be noted that no argument parallel in structure to the present one can be constructed for the sake of discussing the issue of the essentiality of the minimal spatial location of events. For since the subjects of events are physical objects and no physical object can be wholly in two disjoint locations, we cannot have a pair of events which are ‘twins’ which differ only with respect to their place of occurrence. So, such an argument cannot get off the ground.

15 The reason for this is that if an event could have so occurred, it would have been a change in an object other than the object it was in fact a change in. But the subjects of events are essential to them; I argue this in ‘The Essentiality of the Subjects of Change,’ American Philosophical Association, Western Division Meetings, Detroit, April, 1980, and in ‘Events and their Subjects,’ Pacific Philosophical Quarterly, 62 (1981) 138-47. This point figures importantly in Section VI, below.

16 This principle was suggested to me by Michael McKinsey; he suggested that it was relevant to the issue, but he did not necessarily endorse it.

17 See, for example, Plantinga's The Nature of Necessity (Oxford: Clarendon Press 1974), Chapter VI, and Kripke's papers, ‘Identity and Necessity,’ in Munitz, M. ed., Identity and Individuation (New York: New York University Press 1971, 147f,Google Scholar and ‘Naming and Necessity,’ in Davidson, D. and Harman, G. eds., Semantics of Natural Language (Dordrecht; D. Reidel 1972), 266f.CrossRefGoogle Scholar It should also be noted that Kripke, in ‘Naming and Necessity,’ p. 271, mentions a principle concerning the relation between nations and persons, their behavior, and their histories and a principle concerning material objects and their constituent molecules which parallel (7), (8), and (9). And he too remarks that the truth of such principles does not imply that there can be a ‘reduction’ of the entities of the former sort (in each case) to the entities of the latter. In The Nature of Necessity (p. 99f), Plantinga makes the same point about a principle which amounts to (9).

18 The restrictions, qualifications, hedgings, and other details are discussed in my paper, ‘Events,’ op. cit. In that paper, I argue that there are some properties which are such that any event which is a having and then lacking of them by an object at a time is an event which could not, in any possible world in which it occurs, fail to be a having and then lacking of them. This point figures importantly below.

19 No further similarity between events and sets is suggested by this; one should not, that is, conclude from this, for example, that events are set theoretic entities or anything of that sort.

20 It is here that I wish to express my deep appreciation to my friend and colleague, Michael McKinsey, whose many probing questions, helpful suggestions, and encouragement were invaluable to me in the writing of this paper.