1. Free will and the hypothesis of mechanism
In the previous chapter we looked at two arguments meant to show that no choice or action anyone ever makes is a choice or action made freely. Both arguments depend crucially on the idea that the behaviour of people, even their thoughtfully willed behaviour, is no less the mechanical result of prior events than is the behaviour of anything else in the world. Both arguments, that is, explicitly suppose that anyone=s choice or action is just as much the mechanical effect of things that happened earlier as is the behaviour of turtles or robots or weather systems. We can refer to this idea, the idea that the world is a mechanical system in which each state of the system is entirely a causal product of earlier states of the system, as the hypothesis of mechanism. It=s an hypothesis, at least it is for us, for we have yet to consider any argument that it is true. The hypothesis of mechanism is that any event at all, even the event of making a deliberate choice or performing an intentional action, is entirely the causal product of prior events.
A philosopher who holds that no choice or action anyone ever makes is a choice or action made freely, and who accepts one or the other of the two arguments we examined to that conclusion, is called a hard determinist. The hard determinist thinks that everything in the world, including people in their activities of choosing and acting, simply responds to things that happen to it in the way that it does out of its nature. If a rubber mallet strikes a pillow, the pillow will be compressed around the point of impact; if a rubber mallet strikes an anvil, the anvil will not be compressed. Regularities of these sorts mark animal and human behaviour as well. And, for the hard determinist, it is because human behaviour is mechanical behaviour that human behaviour is not free behaviour.
Let us sum up what we have called the