Free Will either exists or it does not exist. The same is true of Determinism. The two cannot, however, co-exist.
Compatibilism is an illogical, but understandable, construct that is embraced by either (i) people who lack Free Will and are compelled to embrace Compatibilism despite its illogical underpinnings, or (ii) people who have Free Will and mistakenly believe that Determinism rules the universe.
Determinism posits that all activity in the universe is both (i) the effect of [all] antecedent activity, and (ii) the only activity that can occur given the antecedent activity. That is what is meant by saying that everything is “determined” (or “pre-determined”) — it is the inexorable consequence of activity that preceded it. In a wholly deterministic universe, everything that has ever occurred, is occurring, and will occur since the universe came into existence (however that might have occurred) can only occur exactly as it has occurred, is occurring, or will occur, and cannot possibly occur in any different manner. This mandated activity necessarily includes all human action, including all human cognition.
As I understand the notion of Free Will, it posits that a human being, when presented with more than one course of action, has the freedom or agency to choose between or among the alternatives, and that the state of affairs that exists in the universe immediately prior to the putative exercise of that freedom of choice does not eliminate all but one option and compel the selection of only one of the available options.
Based on the foregoing:
- If Determinism is true (i.e., the universe is truly and entirely deterministic), then humans lack Free Will because the truth of Determinism means that (a) humans lack the ability to think in a manner that is not 100% caused by prior activity that is outside of their control, as human cognition is simply a form of activity that is governed by Determinism, and (b) there are no such thing as true “options” or “alternatives” because there is one, and only one, activity that can ever occur at any given instant; and
- If Free-Will exists in its pure form, then Determinism is not true because the existence of Free Will in its pure form depends upon (a) the existence of true “options” or “alternatives,” and (b) humans being capable of thinking (and acting) in a manner that is not 100% caused by prior activity that is outside their control.
As I understand Determinism and Free Will, they are irreconcilably incompatible unless (i) Determinism is defined to exclude human cognition from the inexorable path of causation forged through the universe long before human beings came into existence, and/or (ii) Free Will is defined to be include the illusion of human cognition that is a part of the path of Determinism.
As William James aptly observed:
“The issue . . . is a perfectly sharp one, which no eulogistic terminology can smear over or wipe out. The truth
must lie with one side or the other, and its lying with one side makes the other false.”
I could write many pages describing the varied attempts of by Compatibilists to harmonize the irreconcilable concepts of Determinism and Free Will, but it is unnecessary for me to do so, as there is an excellent discussion of this subject on-line at
Compatibilism (Stanford Encyclopedia of Philosophy). It should suffice to say that none of the various arguments for Compatibilism courageously presented on the Stanford website is satisfying, and all suffer from the same flaw identified above — namely, a stubborn refusal to come to grips with the true and complete nature of Determinism and Free Will. Or, as William James less generously observed, all efforts to harmonize Determinism and Free Will are a “quagmire of evasion.”
Notwithstanding the foregoing, if people do, in fact, lack Free Will, then the true and only reason that anyone believes in Compatibilism is because that is what such people are compelled to believe by forces outside of their non-existent control. By the same token, if Free Will does exist, then the people who freely choose to believe in Compatibilism do so based on the mistaken belief that Determinism is true, combined with an emotion-driven irrational effort to harmonize their mistaken belief in Determinism with their psychological desire to believe (correctly) in their own Free Will.