Infinite Regress vs. First Cause: Understanding the Debate

The regress problem is a classic issue facing cosmological reasoning. In short, the objection aims to block the inference to a first (read: primary, fundamental) cause of the contingent order, which many take to be God, by positing an infinite chain of contingent things. “This contingent thing is caused by that contingent thing, is caused by that contingent thing, etc., etc., ad infinitum.”

There are at least two sorts of regress objections:

• The first is that an infinite regress of contingent things exists as a matter of brute fact. That is just the way things are, so stop asking questions about it and enjoy your Crab Rangoon. Call this The Brute Fact Regress.

• The second is that an infinite regress exists and this itself is adequately explanatory; in other words, nothing further is called to account for why any contingent thing exists apart from the fact that it is “turtles all the way down.” Call this The Explanatory Regress.

The Explanatory Regress is considerably more interesting and challenging, since the Brute Fact Regress does not essentially different than the general brute fact objection and can be handled in similar fashion (see my book for that).

Approaches for addressing the Explanatory Regress include:

• Argue the impossibility of such a regress.

• Argue the irrelevance of such a regress.

Further, arguing the impossibility of such a regress itself divides into two approaches:

• Causal Finitism: Asserts that an infinite sequence of causes is impossible (in other words, that any effect cannot be preceded by an infinite number of causes).

• Essential vs. Accidental Causal Series: Distinguishes between causal series that must have a primary member and those that might not. This approach is more restricted than the first.

The latter approach requires understanding Aquinas’s distinction between essentially and accidentally ordered causal series. In short, Aquinas claims that causal series exhibiting “deep dependence” relations – specifically, when the very existence of something is synchronically dependent upon some prior condition or set of conditions that are themselves synchronically dependent for their existence upon some prior condition or set of conditions, etc. — cannot regress infinitely. Why so? Simply because the entity in question does not have the property of existence in virtue of what it is, and so receives existence for as long as it exists from another. In a causal series like this, we must trace back to a fundamental cause that does have existence in virtue of what it is – what Aquinas says must be something whose essence just is its existence (= God) – otherwise we definitely do not have an adequate explanation of how “existence” entered into the causal series in the first place and thus produced the ultimate effect (in our case, the existence of whatever contingent thing we’re considering). It would have just sprung in from nothing, which Aquinas takes to be absurd. So, in summary, an infinite regression of things whose existence is essentially derivative does not answer the question of where their existence derived from. Fairly intuitive, I think.

As noted, Aquinas’s argument that some causal series are necessarily terminating leaves open the possibility that other casual series are non-terminating. Again, for Aquinas, causal series that are accidentally ordered — for example, where a father begets a son, that son begets his own son, etc., — need not trace back to some primary member, because the causal property in question (the power of begetting) actually is had in virtue of the nature of the thing under consideration. Humans, for example, have the power to beget in virtue of what they are, as rational animals. That power, in other words, is not being immediately “borrowed” from some prior condition or set of conditions in its use. (In fact, that is a fairly good way to distinguish between essentially and accidentally ordered casual series: that is, if in causing Z, Y must borrow the power from X to do so, then the causal series X → Y → Z is essentially ordered.  If, on the other hand, in causing Z, Y does not need to borrow the power from X to do so, then the causal X → Y → Z is accidentally ordered.)

I believe Aquinas is right that causal series exhibiting deep dependence relations are either necessarily terminating or non-explanatory, and I argue this case more rigorously in my recent article Is Grounding Essentially Ordered Causation? (December issue of The Review of Metaphysics).

I will not say much about the stronger thesis of causal finitism, for I have not settled my mind on the matter. Pruss and Koons argue in its favor. My friend Enric, on the other hand, has an article (forthcoming in Faith and Philosophy) arguing that classical theists should reject causal finitism. I plan to host Enric for a discussion about this on a future podcast, so more on causal finitism then.

Either way, that is the first approach: Argue that at least a certain kind of causal series is impossible, and that that is enough to argue for God in conjunction with a certain causal or explanatory principle.

Here is the second approach: Even if there were an infinite regress or collection of contingent things, our principle of explanation demands we escape the category of contingency and move to the category of necessity to find an adequate explanation for why there is anything of the type contingent in the first place. (This approach claims an infinite regress is not incompatible with — nor does it rule out the need for — a fundamental cause). Think of this way. If our principle of explanation demands a reason for why there is anything of the type contingent, then pointing to any one contingent thing, or even a regress of continent things, already assumes the thing we are supposed to explain – namely, contingency! Assuming the thing to be explained in your explanation is hardly an adequate explanation, I should think.

OK. Breakfast time.

There is, of course, more that can be said both for and against the regress objection (shamelessly, I discuss the issue at greater length in my book), but this post, I hope, should at least arouse some thinking on the matter.

Related Articles

https://www.catholic.com/magazine/online-edition/so-you-want-to-explain-why-you-believe

https://www.catholic.com/magazine/online-edition/why-to-believe-in-god-simplified