Consider God’s first action. By definition, no act of God preceded that first act. So no causes preceded that action. Rather, God self-determined that action, by performing it. Thus, contrary to Calvinism, self-determining power exists.
Now the Calvinist might object – how is this to be explained? Does it even make sense? But wait. The scripture says in the beginning God created the heavens and the earth. Atheists might doubt the existence of a first cause, but it is contrary to the faith to doubt that God created the world in the beginning.
Perhaps the Calvinist might backpedal and say, yes God has self-determining power, but man does not. That’s worth discussing, but that statement grants that self-determination can and does exist. Self-determination is logical and all arguments that claim self-determination is illogical are false.
With that in mind, let’s look at Turretinfan’s 4 questions about LFW (link).
1) Is it the LFW position that the sum (or product) of all preceding causes(including the state of man's heart) does not determine the choice, but that
given that same exact set of preceding causes (both external and internal) man
could have chosen otherwise? This question is important, because otherwise the
argument is just so much straw-man-defeating, in which we shouldn't be investing
Yes. Again – look at God’s creation. If causal forces preceded and necessitated His creative act, then creation wasn’t in the beginning, was it?
2) Can we meaningfully speak of reasons for choices, reasons that explain the choices?
Yes. Let’s look at the choosing process as Paul describes it in Philippians 1.
21For to me to live is Christ, and to die is gain. 22If I am to live in the flesh, that means fruitful labor for me. Yet which I shall choose I cannot tell.
23 I am hard pressed between the two. My desire is to depart and be with Christ,
for that is far better. 24But to remain in the flesh is more necessary on your
Paul 1) considered both alternatives, 2) projected the consequences of the alternatives, 3) saw the good aspects of both alternatives and 4) was pressed by both alternatives. Paul identified good reasons to choose either alternative, and both alternatives were influencing him to choose them. So after the choice, we can identify one as the indeterminate cause or more commonly: “the reason”. Our self-determining ability required the indeterminate cause and acted in favor of it. Looking for the reason we choose something is looking for the indeterminate cause our self-determining ability required and acted upon.
3) If we can, how can we do so consistently with the concept of libertarian free will?
By admitting that something doesn’t have to determine a choice to be a reason for the choice.
4) So why not just define Free Will as Calvinists typically do, as man choosing in accordance with his desires?
We do not object to the idea that we choose according to our desire – when that notion is properly understood. What we object to is the idea of determinism.
Let’s look briefly at the relation between desire and choice. The Greek term thelo is used for both desire and choice in the New Testament. They seem scarcely distinct, but it’s easiest to see the difference between them when you want something but don’t choose it. Jonathan Edwards saw them both as “willingness”, but desire is “indirect willingness” and has a remote goal and choice is just “willingness” and has a proximate goal. Desire is indirect in that a drunk doesn’t want to avoid drinking, he wants to avoid the bad consequences of drinking. Desire is remote, in that the drunk’s desire is with respect to a future time. “Some day I will stop drinking.”
Understood in this way, saying we choose according to our desire, is really just saying we choose what we choose. The expression really isn’t helpful, as it doesn’t add anything to our understanding. But it’s true, so we don’t object to the expression, even if it’s impractical to use it. What we object to is determinism.