Suppose a mad scientist while you were sleeping gained access to your brain, implanted special microchips, and now has the ability and opportunity to exhaustively control (causally determine) all of your thoughts and beliefs all the time. Although you are unaware, the mad scientist now has control over exactly what you think of and about and — more importantly — exactly how you think of and about it. All of your thoughts about your beliefs and all of your beliefs about your thoughts are under the control of the mad scientist. Moreover, all of “your” evaluations and judgments are not ultimately up to you, but rather, the mad scientist ultimately determines how you judge and evaluate every proposition.
Now suppose you are sitting in a science classroom and are given a pop quiz. Your professor gives you a quiz with ten true/false questions to answer. Unbeknownst to you, the mad scientist is observing all that is taking place and allows your cognitive faculties to get to work. However, although you cannot tell the difference (he causally determines that to be the case), the nefarious neurosurgeon causally determines certain evaluative judgment options (EJOs) to be blocked off or locked away from your access.
Consider some alternative EJOs: good, bad, better, the best, worse, the worst, true, false, probably true, or probably false.
Next, suppose that the mad scientist has causally determined it to be the case that you cannot access the judgments of “bad,” “worse,” “the worst,” “false” or “probably false” while taking the quiz. So, although it seems as if you are entertaining these alternative EJOs, you simply have no opportunity to actually access them. Thus, you always judge each question of the pop quiz in a positive light . . . even when the truth value to half of the questions is actually false!
Now suppose that as you finish the quiz and begin to look it over one last time, the mad scientist presses a button and now causally determines you to affirm the fact that all of your thoughts are causally determined by the mad scientist. Now you affirm the fact that the mad scientist causally determined certain alternative EJOs to be blocked off or locked away from your access.
With this in mind, important questions arise: how could you (the causally determined passive cog at the mercy of the whims of the nefarious neurosurgeon), be able to rationally affirm (apart from mere assumption) that you have judged each question correctly before submitting your quiz to be graded? How would you know which ones were correct (if any) and which ones were, in fact, false? Indeed, as you try to figure this out it hits you — the mad scientist causally determines you to realize the truth — that your current task of evaluating your former judgments is also causally determined by the nefarious neurosurgeon.
As William Lane Craig says, “A sense of vertigo sets in!”
Indeed, if you are causally determined to happily affirm a false belief, then it is impossible for you (in this scenario) to infer a better or true belief. Replace the mad scientist with “physics and chemistry,” “God,” or anything else and one has the exact same rationality problems but for different reasons. Since humanity does possess the opportunity and ability to rationally infer and affirm knowledge claims (to argue otherwise is to affirm it), many know that we possess the libertarian freedom to think and take certain steps while deciding what we ought to affirm and believe. If you disagree, perhaps it is merely because a mad scientist, a deity of deception, or the laws and events of nature have causally determined you to disagree (when in fact, Tim Stratton is objectively correct). There would be no way for you to know.
A sense of vertigo is warranted!
Bottom line: If something or someone else causally determines alternative EJOs to be blocked off and locked away from your access, then how do you know if you should have evaluated or judged otherwise? One can offer question-begging assumptions, but it is impossible to offer rational affirmations. This is one reason that rational thinkers ought to reject the exhaustive causal determinism of humanity.
Stay reasonable (Isaiah 1:18) and live free (Galatians 5:13),
Dr. Tim Stratton