Following are quotes and paraphrases from Chapters 5-6 of A Metaphysics for Freedom by Helen Steward.
It is essential to distinguish between the following:
P1: The question whether determinism is true can only be answered by physics.
P2: Whether determinism is true or false may some day be settled by physics.
P2 does not rule out a philosophical argument bearing on the issue. But some people say deciding if determinism is true or not is not a philosophical question.
In Steward view we make sense of agency daily when we use the concepts of agent, action, and psychology – the psychology of belief, desire, intention, etc., and even seeing, wanting, and trying to get.
She gives two arguments for libertarian free will as ultimately unintelligible. Chapters 6 and 7 address the first one. Chapter 8 addresses the second one. The first is that its denial of determinism merely introduces an unhelpful randomness to causality. She calls it the Challenge from Chance. If it is right to think that a genuine choice has to be something with intelligible roots in such things as an agent’s reasons and desires, libertarian free will not only saddles us with the Challenge from Chance. It looks incoherent, if it insists it was possible, at the moment of decision, that the agent could have made the opposite choice, even when the agent has no reason or desire for the opposite. Even if it were possible to make a choice unrelated to one’s desires, beliefs, or deliberations – perhaps from deep psychological causes – it’s hard to accept that such a cause provides a solid foundation for a coherent libertarian free will (p. 132). It suggests that outcomes are then at least partly a matter of luck. It is partly a matter of luck not merely in that the outcome is not completely determined by antecedent factors, it is a matter of luck to the decision maker. It is not freedom-enhancing. It is an obstacle to control and the operation of agency (p. 141). I skip Steward’s extensive examples to support this.
The concept of action she defends draws on terminology introduced by John Searle. He argues for three ‘gaps’ an explanation of action must take into account.
1. A gap between ones beliefs and desires and any actual decision made.
2. A gap between the decision and the action.
3. For actions extended in time, a gap between the initiation of the action and its completion. A constant voluntary effort is required.
Regarding 2, we often decide to do things and then fail to do them without changing our minds, but due to laziness, inertia, lack of resolve, cowardice, etc. Chapter 7 will deal with responses to the Challenges from Chance such a challenger could make to her claims.