I find that the correct way to treat this problem is to print out all posts that you, Kurieuo and others have written on Aquinas besides all the references and lay them on a big table and try to find out what's all about. But currently I can't do that so I just try to answer your last post and wait for the book.
I was hoping we would continue the discussion on PSR first but I see I need to make some contribution here.
Nils wrote:You have indeed tried to explain the general idea about what was wrong with #6 in the OP but it requires much more understanding of the argument as you see it to be able to write an amended statement.
First I will re-quote the second way
The Second Way wrote:Argument from Efficient Causes
1. We perceive a series of efficient causes of things in the world.
2. Nothing exists prior to itself.
3. Therefore nothing [in the world of things we perceive] is the efficient cause of itself.
4. If a previous efficient cause does not exist, neither does the thing that results (the effect).
5. Therefore if the first thing in a series does not exist, nothing in the series exists.
6. If the series of efficient causes extends ad infinitum into the past, for then there would be no things existing now.
7. That is plainly false (i.e., there are things existing now that came about through efficient causes).
8. Therefore efficient causes do not extend ad infinitum into the past.
9. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God.
I note that you cited my OP but Kuieuo didn't like #6. Any comment?
In order to understand what type of causation Aquinas is referring to, we need to first list the types of causation which I've referred to numerous times.
- Accidentally ordered causal series: This type of series is temporal, i.e. my grandparents having my parents, my parents having me, and so on. My existence today does not depend on the existence of my grandparents, seeing that they are all dead and I'm still typing. This type of causal series is temporal, and can in theory extend backwards in time to infinity. This is NOT the causal series Aquinas is using in his argument.
- Essentially ordered causal series: This type of causal series is simultaneous, not temporal. The example most often used is when I use a stick to push a rock. The rock is pushed by the stick, the stick is moved by my muscles contracting, my muscles contract because of certain neurons firing in my brain, and the neurons firing in my brain fire due to an act of the will. This entire series of causation is interdependent. Take the first one out and the whole chain collapses. This IS the efficient causation Aquinas is referring to. Also note what this series says, it says that a first cause is absolutely necessary, therefore, infinite regress is impossible. A first cause MUST exist, otherwise nothing (of the whole chain) exists.
Essentially ordered causal series make sense to me if you regard them as levels of explanation.
An example: When a chess-playing computer orders castling it evaluates the chess rules - it follows some algorithms - it executes a program line - it runs through some machine code - it handles some computer elements like registers and memories - it uses electrical and-gates and or-gates - transistors and diodes are switched ... down to atoms, quarks etc and finally energy and the physical laws. All these levels are different level explanations of what currently is happening so as I understand this is an example of an essentially ordered causal series, but what is the beginning or the end I don't know. In some way the physical laws are the start because without any physical laws there are no computers for instance. On the other hand without any rules of chess there will not be any draw.
Is this example relevant?
Now you might say, so what. Even if that's the case, how does that even prove God? Well, in 2 ways.
1. Even if you assume an infinite time with an infinite number of accidentally ordered causal chains, looking at each and every one of these infinite events we see that they are composed of smaller events that are essentially ordered, as with any motion/change. In other words, infinite temporal events are composed of essentially order events, each one of which requiring a first.
I understand the thought that there are an infinite number of accidentally ordered causal chains, that they are composed of smaller events that are essentially ordered, each one of which requiring a first. But where does God enter?
2. Existence itself is an essentially ordered causal chain for why do things keep existing at all? Why do things not simply vanish or get annihilated? After all, there is nothing in the inherent nature of contingent things that says they must stay in existence. Therefore, there must be a first cause that is itself uncaused, keeping all contingent things in existence in the here and now.
Now obviously 2 needs to be unpacked a great deal more than 1 for we must once again delve into actuality and potentially and other philosophical concepts such as form and matter, essence and existence, and so forth.
But in a nutshell, that's Aquinas' second way, which is much more nuanced than the first. IMO, the first brings out the argument much more forcefully (and the PSR even more so).
It is far from clear to me how Aquinas second way relates to what you have written in this post. He doesn't mention accidentally or essentially causal ordered series but "efficient causes following in order". He also writes " would be prior to itself" which may indicate a temporal ordering.
Your thoughts, Nils.
Much more could be said but I wait for your comments so far.