Nope. All the objects in my chain have a cause, but the chain as a whole does not, necessarily. This is the crux of the problem. I declare here solemnly that the chain itself is a brute fact that does not require explanations. Whether some objects have a causal chain does not assume the PSR. The PSR says that all things require an explanation, and its negation does not entail that no objects have an explanation. You are confusing necessary with sufficient conditions. So, if I do not assume the PSR, I am free to make models that explain parts of a Universe, but not the whole Universe, or chain.
My example simply shows that you have no possible logical rebuttal that does not posit the PSR in its premises. How do I know? Well, your rebuttal was "the chain cannot account for its existence". Which is valid only under the assumption that "everything must be accounted for (either by contingency or nesessity)". Ergo by assuming the PSR in the premises.
But you are not alone. Leibnitz promoted the principle to self evident truth exactly in order to defeat infinite regress. For, infinite regress, without the PSR, is perfectly possible.
And we do not know today whether the PSR is valid or not. Therefore, we do not know today whether my chain, or the Universe, can be a brute fact (without any account for its existence whatsoever) or not.
In other words, you (and Leibnitz) failed to kill my argument on logical grounds only, without positing a (controversial) metaphysical premise.
So, as long as you do not show me how my chain cannot be a brute fact of existence (without assuming PSR), I will consider my claim of infinite regress to be possible.
Do you have an explanation for your will? For instance, what caused your will to believe in God? And what caused that cause? And what caused that cause that caused you to believe in God? Etc. Is that ultimately necessary, or contingent?
Did it begin to exist without a cause, or is yet another uncaused cause?
Ciao
- viole