A. Hume argues that the debate about freedom of action and determinism is just so much hot air---it is a verbal dispute that will reveal itself as such when the notions of necessity (i.e., determinism) and liberty (i.e., freedom) are defined.
1. We come to have this idea by paying attention to the relation between cause and effect.
a. Causation consists simply in "the uniformity observable in the operations of nature, where similar objects are constantly conjoined together and the mind is determined by custom to infer the one from the appearance of the other."
b. The idea of necessity consists simply in this constant conjunction and inference of the imagination.
2. There is no other idea of necessity forthcoming from perception---no "unbreakable bond" between cause and effect. Our idea of necessity is a product of imagination.
3. This doctrine applies to causation in the external world and to human behavior, as is apparent from our actions.
a. We might think that certain things happen randomly, but we think this only because we are ignorant of all of the relevant factors. Randomness is merely apparent.
b. In our reasoning and planning, we assume necessity.
1. Not incompatible with necessity but with constraint.
2. "A power of acting or not acting according to the determinations of the will".
B. Compatibilism is necessary for morality---we need both liberty and necessity.
1. Without necessity, there would be no regularity in human behavior and without that, no room for moral laws.
2. Furthermore, there must be some regular connection between one's actions and one's motives if those actions