Sullivan on the Principle that Everything Has a Cause
m. j. garcía-encinas

(This is just a draft: notes and bibliography can be found in the published paper)

In two papers arguing that the beginning of the universe has a cause, T. D. Sullivan defends the principle that everything has a cause. Quentin Smith and Chad Allen attack his defence of this maxim. My aim here is, on the one hand, to show that both responses, Smith’s and Allen’s, fail to do justice to Sullivan’s argument, and that Sullivan gets right at least one important thing on the matter: that we have no good reason to disbelieve the principle. On the other hand, I want to argue that it is equally the case that we have no good reason to disbelieve its falsehood, and that Sullivan’s argumentation does not show otherwise. This will leave us agnostic with respect to the principle of causation, a position some may dislike since it means that many important arguments that rely upon the principle would be without foundation.

1. The Principle of Causation

Before considering the main lines of Sullivan’s argument, it would be good to say something about his statement of the principle of causation. Sullivan wants to show that it is reasonable to believe that:

(S) Every contingent thing necessarily has an (efficient) cause of its coming to be.

Yet the principle of causation is, more generally, that:

(PC) Everything has an (efficient) cause.

Assuming that ‘everything’ is to be understood in this context to range over contingent things, and that every contingent (existing) thing comes to be, Sullivan is then arguing that:

(PC’) Everything necessarily has an (efficient) cause.

As (PC’) is a stronger version of (PC), if Sullivan’s argument for (PC’) is successful (PC) will thereby be demonstrated. From now on, and for the sake of the argument, when I speak of the principle of causation I will refer to (PC’) or some version of it, implicitly or explicitly including the clarification that ‘everything’ stands for ‘every contingent thing that comes to be’.

2. First Part of Sullivan’s Argument: The Reductio

Sullivan argues that the principle of causation should be accepted as true since we have no good reason not to believe that it is true, and we have good reasons not to believe that it is false. His argument may then be divided into two parts. The first part starts from the following two premises:

(i) The effect necessarily has a cause (its cause) of its coming to be.

The first premise is then the thesis that causes are, in a strong metaphysical sense, necessary conditions for their effects. There is a real necessity of the effect towards the cause: without its cause, the effect is impossible. The second premise is the assumption that:

(ii) At least one thing (substance, property, event, action, ...) has a cause.

From the suppositions that (i) the effect necessitates its cause, and that (ii) at least one thing comes to be causally, Sullivan correctly argues by means of a reductio ad absurdum that it is false that (1) everything is such that it can come to be without a cause, and that it is true that (5) there is at least one thing such that its coming to be is impossible without a cause.

It should be noted that (1) is not the negation of the principle of causation — and the negation of the principle of causation does not imply (1). Equally, (5) is not the principle of causation — and (5) does not imply the principle of causation. From the fact that a given thing cannot come to be without a cause, it does not follow that everything necessarily has a cause (of its coming to be). So Sullivan’s reductio does not prove the principle of causation. The point is that while arguing for the falsity of (1), and the truth of (5), Sullivan’s aim is not to prove the principle of causation, but to show that there are no good philosophical reasons to disbelieve it. And he does block the main a priori route to the falsehood of the principle by proving that the claim that everything could come to be without a cause is false.

Sullivan complains that Smith has read him as defending, by means of the reductio, the principle of causation — and, consequently, the impossibility that the universe came to be without a cause. As we have just seen, Smith’s charge would be off the mark. However it may be, I would like to make a different comment on Smith’s position. Smith accepts the plausibility of a version of the principle of causation that would allow for the uncaused beginning of the universe:

(P) One thing that comes to be can come to be without a cause, but each other thing that comes to be necessarily has a cause of its coming to be,
where ‘comes to be’ is defined in the following way:

For any x, x comes to be if and only if there is some time t at which x exists and no time earlier than t at which x exists.

Sullivan has replied, appropriately I think, to the two arguments Smith offers for (P). In addition, though, it should be realized that Sullivan’s argument for the principle of causation runs directly against (P) too. Sullivan’s argument is independent of, and does not rest on, the supposition that things exist, or begin to exist in time. So Smith’s definition of ‘comes to be’ cannot be endorsed by Sullivan. For Sullivan does not use the formula ‘the coming to be of the universe’ to refer to the beginning of existence in time of any thing — the temporally first thing or the universe as a whole. Rather, he wants to stress the point that ‘everything’ in the principle quantifies over whatever exists, over whatever it makes sense to say that it ceases, continues, or begins to exist. And then, insofar as it makes sense to say that the universe exists, Sullivan’s argument applies to the universe as a whole, to the first existing thing in time, and to every other occurring stuff within the universe. If Sullivan’s argument is sound, there are no exclusions, at least of the kind Smith requires, for the principle of causation. If Sullivan is right, (P) does not hold. But to see this, we have to consider the second part of his argument.

3. Second Part of Sullivan’s Argument: Contingency

If I am not invalidly inferring ‘Nothing can’ [come to be causelessly] from ‘One thing cannot’ [come to be causelessly], how do I get from the one point to the other? By arguing that if we believe that at least one contingent entity is such that necessarily its coming to be has a cause, then we have no good reason not to believe this is true of all contingent entities that come to be. For all contingent entities agree with respect to the relevant property — being a contingent entity.

In other words, if it can be proven that (5), i.e. that there is at least one occurrence such that its coming to be is impossible without a cause, then the principle of causation may be settled as true. That (5) is true is something that Sullivan has already proved on a priori grounds. But why should it be acknowledged, given (5), that the coming to be of everything is impossible without a cause? From the idea, Sullivan says, that everything is contingent. But, again, how does the contingency of everything support the principle of causation?

Chad Allen says that Sullivan’s line of thinking rests on the proposition: (C) ‘We have good reason to think that all contingent entities come to be in the same manner’. Given (C) and (5), the principle of causation would follow. But, reasonably enough, Allen argues that (C) itself does not seem very reasonable: it is not very judicious to hold that everything has the same type of cause. (Furthermore, Allen contends that, as Sullivan believes that the cause of the universe is a non-physical cause, by adding (C) as a premise, the argument would contradict Sullivan’s whole enterprise, since (C) implies that the coming to be of the universe has a contingent, physical, thing as cause.)

However, Sullivan does not argue, nor does there appear to be any reason why he should accept, that every contingent thing comes to be in the same manner. He does not say anything at all about the way contingent things come to be except, of course, for the assertion that their coming to be is necessarily caused. What Sullivan does argue is that as every thing (that comes to be) is contingent, then if one thing (that comes to be) is necessarily caused, then every thing (that comes to be) is necessarily caused. That is, he wants to reveal some intimate relation between the contingency itself of a thing and its being caused:

"Any need for things to be caused does not seem to depend on a thing’s nature but on the essential structure of a thing qua thing; if any thing that comes to be essentially has a cause, then each thing that comes to be essentially has a cause."

If there is a thing such that its coming to be is impossible without a cause, then every thing necessarily has a cause. This follows because the need for things to be caused is tied to their being things, to their existing as things. The caused existence of things is independent of their natures, of what they are or may be. The causal dependence of every thing is due to its existing as a thing, to its contingent existence.

These ideas closely resemble the old medieval distinction between essence and existence that Thomas Aquinas employed to advocate that everything but the first cause, God, is created:

"While the relationship to a cause does not enter into the definition of a being that is caused, nevertheless it follows from what is bound up in a being by participation, for from the fact that a thing is such it follows that it is caused by another. Such a being cannot exist without being caused, no more than a human being can without a sense of the comic. Yet since to be caused is not essential to the meaning of being as such we can meet with a being that is uncaused."

Aquinas is making here two fundamental pronouncements. First, he affirms that having a cause does not enter the definition or essence of something that is caused: the consideration of the nature or concept of things, the consideration of what things are, yields no relation to any cause. Aquinas, it seems, is anticipating the Humean argument against our having a priori knowledge of a necessary connection between cause and effect, and also against having a priori knowledge of the principle of causation, from the consideration of whatever is caused. Suppose that the movement of a billiard ball causes the movement of another. St. Thomas would say that there is nothing in the movement of one of the balls, nothing in the definition or nature of this movement, that conveys a causal relation with the movement of the other (or with any other thing). We do not find in the concept or essence of what is caused that it has a cause.

The second point Aquinas is making is that because every thing is a being by participation then every thing is caused. Things exist by participation. In considering a thing, not as something with a definition or essence, but as an existing something, it becomes clear that every thing owes its existence to another existent. For existence is not “something” that things have by themselves: the existence of any thing is separable from its essence. As far as every thing is such that its existence does not belong to its nature, its existence is given by another existent.

In what could then be identified as a Thomistic approach, Sullivan argues that the supporting base for the principle of causation is the contingent existence of every thing. Given that the effect metaphysically necessitates its cause, given that everything is contingent, and given that a contingent thing is necessarily caused, then everything is necessarily caused. This is, in short, the main body of Sullivan’s argument. And it is this line of reasoning I will attack in the next section. From the contingent existence of everything, and the necessary causation of a contingent existent, there does not follow any universally quantified causal conclusion.

4. Contingency and causality are separable

From the fact that something is contingent and necessarily caused, it does not follow that there is any relation between its being contingent and its being caused. Contingency and causation are separable. But if they are separable, then even if Sullivan has successfully shown that there is no reason not to believe that it is true that every thing is caused, he has still left open that there is no reason not to believe that it is false.

Following a Thomistic approach, Sullivan argues that the possible nonexistence of every thing that exists implies that every thing necessarily has a cause of existence. Being contingent — or being such that existence is not part of one’s essence, in a more Thomistic terminology — is being derived and externally caused:

"If therefore the existence of a thing is to be other than its nature, that existence must either derive from the nature or have an external cause. Now it cannot derive merely from the nature, for nothing with derived existence suffices to bring itself into being. It follows then that, if a thing’s existence differs from its nature, that existence must be externally caused."

"[I]t cannot be that the existence of a thing is caused by the form or quiddity of that thing (...) because then something would be its own cause, and would bring itself into existence, which is impossible. It is therefore necessary that every such thing, the existence of which is other than its nature, have its existence from some other thing."

Because things (are such that they) could have failed to exist, their coming into being must have a cause outside the things themselves. Because the existence of things is other than their nature (and, consequently, they cannot be the cause of their own existence), their existence must be due to some external cause. I think that these quotations from Aquinas reveal ideas similar to those that Sullivan has in mind when he argues in favour of the principle of causation from the contingency of everything. But this line of reasoning is far from being uncontroversial.

The thesis that there is metaphysical distinction between essence — what things are — and existence — that by which things are — is implicit in the previous reasoning. However, two lines of reasoning undermine this thesis. First, one might argue that the distinction between essence and existence implies a logically fallacious predication of existence. And second, even if it does not imply the predication of existence, the thesis is nonetheless clearly intended to state a real metaphysical distinction. But it may be questioned whether, besides the fact that things are what they are, there is also the fact that things are. Are things, on the one hand, a complex of exemplified universals in some kind of material stuff and, on the other hand though actually inseparable from the first, the act of existing of this complex? The standard view denies this real distinction. Existence, it says, is simply the instantiation of some universal property. To exist is to be something. We cannot separate a thing’s being from its being that thing.

I think that neither of these two arguments reaches its point, but to examine them would lead us far away from the issue of this paper. However, it is not necessary to press on the separability thesis between essence and existence, because its acceptance does not support the principle of causation. That existence differs from essence does not prove that everything is caused, unless it is previously accepted that existence is caused. The arguments in the foregoing quotes do not prove, but presuppose that existence should be caused.

Because things are such that they could have failed to exist, for them to exist (rather than not), they must have a cause outside themselves. This claim presupposes the principle of causation. For why should the existence of things be caused? Not because they could have failed to exist, since they might exist by chance. Maybe because something that does not exist cannot give existence to itself and so, it must receive its existence from outside. But, again, why should existence be given, received or derived? There is nothing in the idea that something exists (or in the idea that something could have failed to exist, or in the idea that the essence of something does not entail its existence) that implies that its existence is given (by oneself, or by something external). The existence of things might be spontaneous. Sullivan should treat being contingent and being caused as separable concepts if he is not to beg the question. Yet Sullivan writes:

"It would be entirely arbitrary to say that a contingent entity needs a cause for its emergence provided that it is blue, but not if it is red. The relevant property is not its colour or its size, but its contingency.

(...) [I]t is arbitrary to insist that contingent entity e1 needs a cause but contingent entity e2 has no such need, that blue things, say, can just pop into existence, but not red things."

Sullivan reasons as follows. If we attempt to divide the set of all contingent entities into the ones that are (necessarily) caused and the ones that are not, the partition would seem entirely arbitrary. Red things, say, would be caused, but not blue things. And yet there is no reason these properties should correlate with causation. So if one contingent thing is (necessarily) caused, all contingent things are (necessarily) caused.

This reasoning is defective. To see why, consider, for example, the set of all geometrical figures, and suppose that every non-equilateral figure happens to be blue and every equilateral figure red. It is not arbitrary to divide the figures into equilateral and non-equilateral because red figures would be equilateral and blue figures would be not. That they are blue or red is beside the point. Colour is irrelevant, and so is any other property unless there is shown any relation between it and being equilateral. The case of causation is similar. It is inadequate to maintain that red things are (necessarily) caused but not blue things as if implying some relation between colour and causation. It is inadequate precisely because a thing’s being red or blue is completely irrelevant to its being caused. So, after all, it might be that red things are caused while blue things just pop into existence. And the same is true for any other property, including contingency. The only relevant property is their being (necessarily) caused or not. If it is not shown that there is any essential connection between being (necessarily) caused and being contingent, it is as arbitrary to make the division (between contingent caused things and contingent uncaused things) as to deny it (maintaining that all contingent things are caused). Granting the contingency of everything, there are as many reasons to believe the truth of the principle as to believe its falsehood.

I cannot end without considering some marginal comments Sullivan makes on behalf of the principle. He writes that (1) given its natural appeal and the absence of a good philosophical argument against it, it would seem irrational to reject it; (2) the principle is obvious in a customary sense; and (3) it occupies a high positive position in the epistemological hierarchy. I am not saying that there are better reasons by which one might try to justify his beliefs, but these are clearly not good philosophical reasons to embrace the principle of causation. Natural appeal has been proved too many times to be the wrong approach to any well founded thesis and, in any case, it should never be enough. On the other hand, it is not clear what Sullivan means by ‘obvious in a customary sense’. He mentions the Aristotelian argument for the principle of non-contradiction. But while the principle of non-contradiction cannot be denied without presupposing the same principle, this is not the case with the principle of causation. And as for (3), it still has to be convincingly argued that science, while searching for laws, explanations, and reasons, uses the principle of causation.


Sullivan has shown that there are no good (a priori) reasons to disbelieve the principle of causation. Accepting that there is a least one caused thing and that causation involves some metaphysically necessary connection in the sense that the effect necessitates its cause — neither of which presuppositions Hume would have granted — it naturally follows that it is not true that everything can exist without a cause. However, Sullivan has not shown that there are good philosophical reasons to believe the principle causation. To establish this, some closer link should be established between being an occurrence and being caused. Hume taught us that what an occurrence is is separable from its being caused. To add now that every occurrence exists contingently does not suffice to close the Humean gap. The principle of causation remains a wishful conviction.