Libertarian free will (as opposed to compatibilism) is defined as the ability to choose A or non-A.
Is libertarian free will (LFW) true?
It is necessarily true since otherwise one couldn't evaluate the truth value of the question "Is LFW true?" because you could only conclude what you were determined to do which gives no foundation for truth
There is one exception which would be if one were epistemologically infallible. This would then give a solid foundation for truth under determinism.
Yet this is obviously false since it is possible for me to argue, and believe to be true, that 2+2=3 which demonstrates that I must have varying degrees of determined fallibility (assuming determinism). And since fallible determinism gives no foundation for truth we must again reject determinism.
Therefore LFW is true.
What does this imply? (Or how can we metaphysically justify the existence of LFW)
We cannot be purely material beings since we would be determined by our neurological pathways or other laws of nature.
If we were then you are either stuck with cast iron laws of nature which results in cast ironly determined "choices", or accept quantum randomness which implies a complete scatter gun type "choice".
And as above this gives no foundation for truth and therefore must be rejected.
This implies then a substance dualism (trichotomy or more) of man since can provide a foundation for real choices as it can be neither random nor subject cast iron laws. At present I can't elaborate on what this non-material substance is apart from the fact it provides the necessary metaphysical foundation for LFW.
Finally it implies that the will is basic and as such causes itself.
