This was written by me, and represents the most complete, concise and clear answer I could come up with. Note that it is only about 650 words. This would be about 2.5 to 3 pages if written out, given average student handwriting.

3. Edwards ends his essay on the cosmological argument by saying that the theist is stuck with one unexplained brute fact. What does he mean by this, and why does he think it is true? Edwards’ discussion is based on causal versions of the cosmological argument, but Taylor presents a version based on the principle of sufficient reason (PSR). What is Taylor’s version of the argument, and how does it differ from the causal version (what are its similarities and differences)? Is Taylor in fact stuck with any ‘brute facts’?

The version of the cosmological argument that Edwards criticizes, like most versions, including Aquinas's, is based on causation. A basic statement of the argument is:

1. Everything must have a cause.
2. Nothing can be its own cause.
3. Either the series of causes is infinite, or it is not.
4. If it is, then there is no first cause, but in such a case the entire infinite series itself would need a separate cause, namely God.
5. If it is not, then the series initiates with a first, uncaused cause, namely God.

Against this, an atheist might claim that rather than God being the uncaused cause, perhaps the physical universe itself is the uncaused cause. Either way, we have one uncaused cause. Edwards denies both of these positions, ultimately because he thinks that each of them is stuck with a brute fact – something that exists but is not caused by anything else.

The problem comes form premises 1 and 2, which state that everything must have a cause, and nothing can be a cause of itself. Premise 2 is difficult to deny, since causation takes time, and so for something to cause itself to exist it would need to be able to exert causal influence before it exists, which is certainly impossible. Since Premise 2 is solid, the theist must exempt God from Premise 1, and the atheist must exempt the physical universe from Premise 1. Edwards thus claims that both the atheist who thinks the universe is uncaused, and the theist who thinks that God is uncaused, are embracing brute facts -- the existence of something without a cause.

Edwards' own position consistently applies Premises 1 and 2 to absolutely everything. He claims that all individual things are caused by something before it, and this forms a series that goes back infinitely far in time. There is no uncaused God, nor is there an uncaused 'physical universe'. The physical universe is nothing but the individual things that make it up, and so long as each of these individual things has a cause, then everything has a cause. It is a mistake, Edwards claims, to go on and ask for a cause of the whole physical universe if every individual thing in the universe has an explanation. Edwards thus believes that only his own position is free of brute facts.

Taylor's version of the cosmological argument is based not on causation, but on explanation. One version of this would be:

1. Every fact has an explanation (PSR).
2. A given fact is either contingent, in which case its explanation appeals to one or more other, external facts; or is necessary, in which case its explanation appeals only to itself.
3. The existence of the physical universe, and things in it, are contingent -- they might not have existed. Hence they must be explained by something else.
4. The series of explanations cannot go back to infinity, and so must end at some first fact.
5. This first fact, because there is no prior fact that explains it, must be necessary, that is, self-explained.

PSR is playing a role in Taylor’s argument that is analogous to the role played by Premise 1 in the causal version of the argument. The difference, though, is that Taylor's argument does not exempt anything at all from PSR, whereas in the causal version, something must be exempted from Premise 1. On Taylor's view, everything is explained. Some are explained by things other than themselves, and the rest are self-explained, but nothing is unexplained. Hence Taylor's view has no brute facts. Taylor’s argument is not based at all on causation, and so need not say anything about whether everything is caused or not. It is open to Taylor to say that the existence of God is not caused. But even if that is true, Taylor would say that there is an explanation for God’s existence. Causes are one way to explain things, but not the only way.