Suppose there is a man, John, who holds a terrible fear of spiders.Whenever presented with a spider, John’s outward behavior always adopts a stance of fear. Based on this would we conclude that John lacks freedom in his arachnid interactions? No, ordinarily we would contend that John may be free to react differently, perhaps to display calculated indifference or hatred instead, but is constrained by himself, i.e. his fear of spiders, to react accordingly. Thus all of John’s interactions with spiders are subsumed under a law-like statement:
s1 - If presented with a spider, John will react with fear
Assuming that we know John will never overcome his extreme arachnophobia, this law-like statement will allow us to predict John’s behavior in arachnid interactions with complete accuracy. That we can successfully predict John’s behavior in arachnid-involving situations does not seem to deter us from asserting John’s freedom in those situations. You might claim that John’s arachnophobia is somehow distinct from John, thus it is a force “external” from him in some sense that imposes in a deterministic fashion upon his will. But this could similarly be done for just about any mental phenomena, even preferences that are normally taken to be expressions of free-will. This attempt at distinguishing only works so long as you leave what precisely is John or John’s will undefined. So far as you provide a definite reference for what constitutes John or John’s will, such attempts will either fail or not account for all phenomena that are taken as expressions of John or his will. Now, suppose there is an omniscient entity that knows everything about John. This entity could extrapolate the following law-like statement about any of John’s behaviors:
s2 - If under conditions C, John will X
No matter how unique or nuanced a situation, the entity need only expand the variables and counterfactuals accounted for in C to make a corresponding law-like statement that enjoys complete accuracy. This entity’s omniscience implies it would be able to use these law-like statements to predict all of John’s actions before he actually does them, making the entity’s claims about John actual predictions instead of retrospective historical facts. The complete predictability of John’s actions via law-like statements in no way suggests John is not capable of freedom in those situations. This in turn suggests that complete or universal predictability through law-like statements does not disprove free-will. Instead, complete predictability is quite besides the point of free-will, so to speak.