IMO Garrigou-Lagrange was right to distinguish between the internal, being the principle of identity applied to a particular essence taken of itself,  and the external PSR, just being efficient causation. With this in mind, it sort of becomes obvious the theistic implication. 

UGADawg wrote:

If PSR is false, the causal principles behind hierarchical causal series are suspect, e.g. potentials could possibly be actualized without anything doing the actualizing. So you could, in principle, just pick out any entity composed of act / potency to terminate the causal series.

I don't see how "possibly be actualized without anything doing the actualizing" coheres with "any entity composed of act / potency". An entity that is actual with respect to the species of change but perhaps potential in some other respect would be "doing the actualizing," wouldn't it? 

Or do you mean that we have a dichotomy: either a first cause that is purely actual, in all respects, or no causality?  That doesn't square with what you say about picking out any entity partly actual partly potential to terminate the causal series.
 

Last edited by ficino (11/09/2017 7:50 am)

What to do with the PSR is a big question. A while ago, a poster named Tyler was propounding the argument made by Keith Parsons in his debate with Feser. Parsons maintained that we have no assurance that our cognitive faculties aren't deceiving us. So we have no assurance that what we think is the sufficient reason in any particular case is the sufficient reason. So everyone is in the same boat, whatever we think about the PSR. I don't recall anyone actually refuting this.

I think if you want to go further down the path you're pointing to, UGADawg, you may want to drop the language of potentiality and actuality. If the PSR is false, then I would think a hierarchical causal series falls with it, since we couldn't establish the "end" toward which the whole series is ordained/oriented, could we? If the PSR is false, I don't see where something purely actual actualizing a potential is even going to be a requirement of any explanation of change. We'll be left with something like Pragmatism, maybe. And that's fruitful in its own way.

 

Last edited by ficino (11/10/2017 8:52 pm)

I am probably misunderstanding De Esse et Essentia, but I cannot help thinking that talk of things, some of which make acts of existence and some of which do not, is incoherent. 

RomanJoe, when you say that its act of existence is the reason why a being can be distinguished from nothingness or possible existence, I think you're speaking imprecisely. Do you mean, "why a being can be distinguished from a being that does not exist, or from a being that exists in some possible worlds but not in the actual world"? 

It seems to me that we wind up with positions like "Egyptian Socrates and Athenian Socrates differ in that Athenian Socrates was granted an act of existence, but Egyptian Socrates was not granted an act of existence." This seems very unfruitful to me. It really shows up in Aquinas' discussion of immaterial substances, where the substance serves as the analogue of matter, and the act of existence does the work of form. A substance exists by definition. It's just duplication to say that a substance goes on to make an act of existence. There are no substances that don't exist.

Are there some things in being that DON"T make an act of existence? How is it not trivially true to say that a being's reason for existing is its existence?

I'd need to brush up on RGL again but could one still hold to ~PSR by admitting that every being needs an act of existence to explain its distinction from nothing, but that said act of existence could itself be a brute fact?