Compatibilism is an example of the old "bait and switch" sales tactic applied to moral philosophy. The bait is that you can have your moral cake (responsibility stemming from free-will) and Humean-Kantian causality (time sequence by rule) too. The switch is that the kind of "free will" that is compatible with time sequence by rule does not support human responsibility.

To be responsible for an act, one must be the origin of that act. If the act is predetermined before we were born, as determinism claims, clearly it does not originate in us or anything we did. So, compatibilism is fraud.

The Compatibilist Notion of Free Will

Further, the idea that "free will" means we can do or choose what we desire (or something similar), reflects a surprising lack of reflection and analysis. If there is free will, it comes into play when we are faced with choices. We have to make choices when we desire two or more mutually incompatible outcomes. Option 1 advances the fulfillment of one set of desires, and option 2, that of another set of desires. So, whatever choice we make will tend to advance some motivational factors at the cost of others. No choice is what we desire simplicitur.

We can't evade this logic by bring in some utility function (money, libido, action potential, etc.) to determine what we most desire. This is because motivational factors incommensurate. We cannot reduce them to a single utility function or measure of value. No amount of cash can equate to being unable to breathe. No amount of free breathing will pay for food and shelter.

Since the 19th century many philosophers have sought to clothe their theories in such mathematical garb, but we simply can't describe the indenumerable and unmeasurable numerically, for any proposed number has no determinate relation to what they seek to describe. So, we can't say that we choose whatever has the highest utility. All we can say is that what we choose, we value most. This value, however, is not mathematical, but conative. Our experience of choosing is not mathematical, but rational. So, no calculation can show a choice to be "most valued," "most desired," before we choose it.

The So-Called Problem

If free will is incompatible with strict determinism, and determinism is a consequence of causality, then surely we cannot be the cause of our acts. Hence, whether of not determinism is true, we cannot be the cause of, and so responsible for, our acts. Thus, there is no free will in a sense that would make us responsible.

This argument is fallacious, resting on an equivocal use of "cause." Clearly, if we are the cause of, and so responsible for, our free acts, we cannot be using "cause" in the Humean-Kantian sense of time-sequence by rule. What other sense is there?

The problem is that most modern philosophers are too lazy to study the history to philosophy. It shows that for over 1800 years, philosophers distinguished two kinds of efficient causality: accidental (Humean-Kantian time sequence by rule) and essential (the actualization of potency).

We all know that if you plant tomato seeds, you are the cause of the tomato plants that subsequently sprout and that there is a rule linking the first event (planting of a certain type of seed) to the second event (the subsequent sprouting of the corresponding plant). This is an example of accidental causality. If you've read Hume, you also know that there is no necessity linking the first event to the second. Since we have two separate events, there is always the possibility that an event may intervene between them to disrupt the expected sequence.

Because accidental causality has no intrinsic necessity, it is a strange basis for arguing that whatever we choose, we choose of necessity, i.e. that we have no free will that would be the basis for moral responsibility.

Those who have done their homework/due diligence know that in his Metaphysics Aristotle distinguished a second kind of causality, which is the kind that makes us responsible for our considered acts. This is essential causality. Aristotle's paradigm case is a builder building a house. Of course, the cause is the builder building, and the effect is the house being built. Aristotle notes that the builder building the house is identically the house being build by the builder. (These are identical because they are merely different ways of describing the same event.)

Since there is only one event, and not two as in time sequence by rule, no event can intervene to disrupt this kind of causality. Since the cause and effect are inseparable (we can't separate building and being built), cause and effect are linked by an intrinsic necessity. While the prior physical state of (a pile of building materials) does not necessitate the form of the finished house, something being built necessitates an act of building.

If we think about Aristotle's example, we see that it is simply an instance of a potential (of the materials to become a house) being actualized by an agent (the builder). So, any actualization of a potency by an agent is an instance of essential causality.

We can now see that free choices are not uncaused choices. They are the actualization of one of several possible courses of action by the moral agent. So, causality and free will are compatible, just not the kind of causality modern philosophers think of.