There’s only a problem with the notion of free will if you choose to analyze it in terms of certain primitives that you then take as given, as incapable of further analysis themselves, or as just ‘obvious’. So if you insist that things happen ‘according to the laws of physics’, but neglect to ask how the laws of physics make things happen, then you can say that since everything happens according to the laws of physics, and those laws aren’t up to us, what happens isn’t up to us, and we aren’t free.
Likewise, if you insist that things ‘cause’ other things to happen, but omit any question on how it is that such causality works, you can find causes for everything that occurs, which aren’t up to us, stretching back to the big bang or infinite past, and hence, what happens isn’t up to us.
Or, you want to say that things occur ‘randomly’. Again, if you refuse to question how things might happen randomly, if you think no theory is possible or needed for the world grabbing into a universal probability distribution to select one of the possible things and sprinkle it with fairy dust to make it actual, then a random occurrence isn’t up to us, and leaves no room for free will.
These are all perfectly consistent stories. However, they all feature an essential black box, some ‘buck stops here’ primitive notion that isn’t further analyzed. Now, this isn’t in itself grounds to discard them: it may well be that explanation only goes so far, and at a certain point, we must accept some brute facts. But it’s essential to these narratives that you don’t try to pry open the box; otherwise, they just fall apart.
But if these stories are consistent, then so is the following. Everything in the world happens through an act of free choice; that is, everything happens through the intention of an entity that could have intended otherwise. This is a black box: we don’t ask how such free choice works, we just accept it does—bringing it onto the level of natural laws, or causality, or randomness. (This is if course just the notion of occasionalism.)
This world would not necessarily appear any less lawful than ours: like a weaver choosing where to put what colour strand to produce an intended pattern, events in this universe could be arranged such as to be amenable to a description in terms of certain laws of nature—only that those laws would, then, be of a descriptive rather than prescriptive sort: they would exist because the events are arranged a certain way, rather than events being arranged that way by dint of the laws’ decree. (In the philosophy of science, this position is generally known as ‘Humeanism’.)
Of course, we don’t need to go all-out occasionalist to get a story with a meaningful notion of free will. According to our best current understanding, the laws of nature are such as to not produce a unique future from a given present state: there’s wriggle room. Like the rules of chess don’t uniquely determine the game to be played, the laws leave options. Typically, it’s asserted that these options are selected randomly; but there’s nothing that says they can’t be filled by choices. It’s just exchanging one black box for the other.
The only apparent problem for free will is then that some, overly impressed with a simple naturalistic narrative, fail to see the black box nature of the explanations they prefer to adhere to (e.g. natural laws + random selection), and insist that everything must be elucidated in those terms. This is an elementar misconception, but unfortunately often takes on the guise of a fundamental and unquestionable axiom, which tends to make these discussions somewhat circular.
