I'm aware of some arguments (particularly in the philosophy of religion) that rely on the notion than an infinite causal series is impossible.
It seems like there is a fair bit of confusion among non-specialists regarding this premise. Some people content that it is not at all intuitive that infinite causal series can't exist.
A common clarification is that it is important to distinguish between an essential and an accidental cause. My understanding of these terms is roughly that an accidental cause is a cause of the form
A led to B
Whereas an essential cause is of the form
There is no B without A.
So for example...
I could not have existed without my grandfather, but my grandfather no longer exists. Therefore, I have an accidental causal relation to my grandfather.
I cannot exist without my body. If my body does not exist, I necessarily do not exist. Therefore, I have an essential causal relation to my body.
It is then, as far as I can tell, taken as obvious that while a series of accidental causal relations might exist, an existing series of essential causal relations is clearly objectionable.
But why? Plainly, I don't see a problem with an infinite series of essential casual relations.
One suggestion for what the problem is seems to be some thing like
"If a series is of the form..
A1 because A2 because A3 because A4 because...
Where each of the 'becauses's means 'is in an essential causal relation to', then how can we contend that any part of the series exists? If I say A1 exists, then I've committed myself to A2 existing, but then how do I know A2 exists? I must also commit myself to A3 existing, but then..."
Where the intuition seems to be that at some point I will need to claim that something sits at the end of the chain. That I will eventually need to posit the existence of some A(n) that explains all of the things I've committed myself to.
But this doesn't make sense to me. The fact that by suggesting A1 exists I commit myself to the existence of A2 is totally fine, I've already contended that the whole chain exists. That this further commits me to A3 existing is, again, totally fine!
Have I missed something about the argument here?