Ability to do otherwise

The incompatibilist view of the ability to do otherwise suggests that if we rewound time without altering anything, a different outcome should be possible. But if I chose A because I wanted A, why wouldn’t I choose A under the exact same conditions? If you tell me, "Imagine rewinding time a million times, and each time you still order the chocolate cake instead of the vanilla one," my response would simply be, "Well, of course—why would I pick something else if everything is identical?"

What compatibilists mean by the ability to do otherwise is this: Had I wanted otherwise, I could have done otherwise.

Suppose determinism is true, and I decide to take the bus instead of walking. Was I able to walk? In this scenario, determinism means that the past, along with the laws of nature entailed that I would take the bus.

But part of the past is that I wanted to take the bus, and I didn’t choose to walk. If I had chosen to walk, then something in the past—perhaps my preferences, my thoughts at that moment, or some small external factor—would have been slightly different. And this is entirely consistent with determinism.

At this point, the incompatibilist might object, saying, "But you couldn’t have wanted otherwise!" The compatibilist’s response would be: Why not? If the past—including my thoughts, desires, and reasons—had been slightly different, then I would have chosen differently. And determinism does not require that the past is fixed in some absolute, unchangeable way.

A person can act in ways that, had they done so, the past or the laws of nature leading up to that moment would have been different. After all, the laws of nature are contingent.

Therefore, compatibilists maintain that even if an agent was determined to act as they did, they still retained the ability to act differently. The mere fact that they did not exercise that ability does not mean they lacked it.

Our decisions are part of the chain unfolding in the world. It’s not as though events happen despite our choices—rather, they happen because of them. The future unfolds as a result of our deliberations, intentions, and actions, not in a way that bypasses or negates our agency.