A reader asks:
Are all infinite regresses (regressions?) vicious? Why the pejorative
label? Of the many things I don't understand, this must be near the
top of my list, and it's an ignorance that dates back to my undergrad
Intro to Philosophy days. When I first read the Thomistic cosmological
proofs, I found myself wondering why Aquinas had such trouble
countenancing the possibility that, as the lady says, "it's turtles
all the way down."
Without a first, there can't be a second... so what? It doesn't follow
that there must be a first element to a series. What makes a
temporally infinite series (of moments, causes/effects, etc.)
impossible?
No, not all infinite regresses are vicious. Some are, if not 'virtuous,' at least innocuous or benign. The term 'benign' is standardly used. The truth regress is an example of a benign infinite regress. Let p be any true proposition. And let 'T' stand for the operator 'It is true that ( ).' Clearly, p entails T(p). For example, *Snow is white* entails *It is true that snow is white.* The operation is iterable. So T(p) entails T(T(p)). And so on, ad infinitum or ad indefinitum if you prefer. The resulting infinite series is unproblematic. Whether you call this a progression or a regression, it doesn't cause any conceptual trouble. Nor does it matter whether you think that infinity is potential only, or hold to actual infinities. Either way, the truth regress is a nice clear example of an infinite regress that is benign.
So some infinite regresses are benign.
Setting aside the lady and her turtles, suppose, contrary to current cosmology, that the universe has an infinite past, and that each phase of the universe is caused by an earlier phase. Suppose further that there is nothing problematic in the notion of an actual (as opposed to potential) infinity, and that there is a good answer to the question of how, given the actual infinity of the past, we ever arrived at the present moment. Granting all that, the infinite regress of causes is benign.
But note that one cannot explain why the universe exists by saying that it always existed. For even if there is no time at which it did not exist, there remains the question why it exists at all. The universe is contingent: it might not have existed. So even if it exists at every time with earlier phases causing later phases, that does not explain why it exists at all.
To say that the universe always existed is to say that it has no temporal beginning, no temporally first cause. But this gives no answer to the question why this temporally beginningless universe exists in the first place.
Here is where the theist invokes God. God is the ontologically, not temporally, first cause. Now if Mill asks, "But what causes God?" the answer is that God is a necessary being. If God were a contingent being, then a vicious infinite regress would arise. For one cannot get an ultimate explanation of U if one invokes a contingent G. And if there were an infinite regress of Gs, the whole series would be without ultimate explanation. Thts is true whether the regress is potentially infinite or actually infinite.
If we compare the truth regress with the regress just mentioned, we can perhaps see what makes the latter vicious. The viciousness consists in the failure to satisfy the need for an explanation. P if and only it is true that p. No one will take either side of this biconditional as explaining the other. But explanation comes in when you ask why the universe U exists. If you say that U exists because G caused it to exist, then you can reasonably ask: what caused G? The classical answer is that G is causa sui, i.e., a necessary being. The buck stops here. If, on the other hand, you say that G is contingent, then it cannot be causa sui, in which case the regress is up and running. Because the explanatory demand cannot be satisfied by embarking upon the regress, the regress is said to be vicious.
To answer the reader's question, there is perhaps nothing vicious about a temporally infinite regress of empirical causes. But that gives us no explanation of why a temporally infinite universe exists in the first place.
Recent Comments