The “Consequence Argument” is a powerful argument for the conclusion that, if determinism is true, then we have no control over what we do or will do. The argument is straightforward and simple (as given in the Stanford Encyclopedia of Philosophy):
Premise 1: No one has power over the facts of the past and the laws of nature.
Premise 2: No one has power over the fact that the facts of the past and the laws of nature entail every fact of the future (i.e., determinism is true).
Conclusion: Therefore, no one has power over the facts of the future.
Premise 1 seems awfully secure. Authors of history books might change people’s beliefs about the past, but try as they might, they won’t actually change the past. Similarly, scientists may write about the laws of nature however they please, but nothing they write will change those laws. No one can control the facts of the past, or the laws of nature.
Premise 2 looks pretty good too. For at least great big patches of nature, events happen because of the way things are or have been, and because of the continuous governance of the laws of nature. True, there are subatomic phenomena that seem to be indeterministic (Einstein was wrong, and God or nature does seem to roll teensy-weensy dice). But for whatever reason, it also seems that as these subatomic bits are assembled into larger parts of nature, the dice rolling seems to no longer have any effect, and at that point we enter upon a deterministic universe. Certainly by the time we get to big globs of neurons within the skulls of homo sapiens, wired up to eyeballs and limbs, we are in a domain where the fact is that the facts of the past and the laws of nature entail every fact of the future.
And the conclusion follows: we have no power to affect the future. So that’s it. We’re done.