RoboMastodon said:
Considering how predictable humans behave, I doubt our behavior is very far from determinate and if it is indeterminate, it is because of quantum events leaking into the macroscopic world.
If we examine this theory more carefully, we'll see it doesn't hold itself well.
You say that whenever a human behaves in an unpredictable way, it is because of some random quantic variable.
There are individuals who act in more unpredictable ways than others; some people are complete excentrics, whose every action is, by normal standards, unexpected.
If we are to accept your theory, then quantic events, which are random (and not suitable to be influenced by someone's "personality") somehow work different in these people.
I must ask you again: do animals have "free will"? Plants? Fungi? Protists? Bacteria? Zygotes? Like I stated before, you seem to be making up a new kind of "special indeterminism" just for free will to exist. I must ask you to substantiate the assertion that our brains aren't simply following the laws of physics.
Of course the brain, and the whole body, follow the laws of physics. But these are not what determine a man's actions.
Any choice you make will have, as its physical result, certain brain reactions which follow the laws of physics.
Edit - Aquinas' argument doesn't make much sense: "We have to make a decision and in order to make a decision we have to decide to make a decision" is what it reads to me... I don't see why this would progress ad infinitum. If you are sitting in a room studying and there is some construction noise outside that you are not aware of because you are concentrated. Suddenly, a large object or something is dropped and you immediately become aware of it. This is due to an action potential being fired off in one a set of your neurons. You see, neurons behave by an "all-or-nothing law" they either fire or they don't, and they require a certain amount of stimulation before doing so. In other words, the "choice" to react to the sound is merely the result of neurons firing off--there is an "initial deliberation" and it is physical, it doesn't need to regress ad infinitum.
That is not what a deliberation means; he uses the definition set down by Aristotle. To deliberate is to think about possible courses of action, on what to do.
A man will make a decision; his decision is based on what he thinks (his values, his ideas, how he perceives the current situation, etc); however, he can, with his will, influence these variables (which will determine his action); still, when he makes the decision to influence his intellect this decision (a volition of the will) is also determined by his intellect; and he can alter this influence; but this decision to will depend on his intellect, and so on. This cannot proceed to infinity; ultimately, there is an external principle, God, driving man towards doing what is good, but leaving the decision open to the individual.
When you hear a sound, there is no choice; your body is affected by the sound and translates it into the experience you have. You can't choose not to hear it, as you can't choose not to think, and as you can't choose to do something in which you don't see any good in.