Free will or determinism?

Are your choices genuinely yours, the product of a fixed chain of causes, or both at once?

Libertarian free will

We really are free. At the moment of choice, more than one future is genuinely possible, and we settle which one happens. The universe is not fully determined, at least where minds are concerned.

Best argument: Our experience of deliberating is as direct as any evidence we have. When you weigh two options, you are not watching a result being calculated; you are making it. If we abandon this, we abandon the basis of responsibility, and there is no scientific finding that actually proves the future is fixed. Modern physics itself contains indeterminism at the quantum level, so the door is not closed.
Strongest objection: Randomness is not freedom. If your choice was not determined by your reasons, character and history, then something else settled it, and an uncaused event inside your head is chance, not control. This is the so-called luck objection: the more a choice escapes causation, the less it seems to be yours.
The reply: Agent-causal libertarians answer that the agent, as a whole persisting being, causes the decision, not a prior event. The choice is neither random nor fixed by earlier states; it is made by you. Critics reply that this names the mystery rather than solving it.
Defended by: Immanuel Kant, Thomas Reid, Robert Kane, Timothy O'Connor

Hard determinism

Every event, including every choice, follows from prior causes. Since you could never have done otherwise, free will in the sense that matters is an illusion.

Best argument: Science has explained ever more of the world through causes and laws, and the brain is part of the world. No neuron fires without a physical reason. Your desires come from your genes and history, which you did not choose. To be ultimately responsible for a choice you would have to have chosen the self that made it, which is impossible. So ultimate responsibility is impossible too.
Strongest objection: The view seems to undermine itself and our practices. If nobody deserves blame, it is hard to justify punishment, gratitude, or even the claim that hard determinists should be believed. And it may overreach: quantum physics suggests the universe is not strictly deterministic after all.
The reply: Many modern defenders call themselves hard incompatibilists. They grant that indeterminism may be real but argue that randomness would not give us control either. Without free will, they say, we can still restrain dangerous people for protection, as we quarantine the sick, while dropping the idea that anyone deserves to suffer.
Defended by: Baruch Spinoza, Baron d'Holbach, Derk Pereboom, Sam Harris

III

Compatibilism

Free will and determinism can both be true. Being free means acting from your own reasons without coercion, not escaping causation altogether.

Best argument: Think about what we actually check when we hold someone responsible: did they act knowingly, on purpose, without a gun to their head, from their own values? None of that requires an uncaused event in the brain. A choice caused by your reasons is not less yours; it is exactly what makes it yours. This is the freedom worth wanting.
Strongest objection: Critics call this a verbal trick. If the past and the laws of nature fixed your act, you could not have done otherwise in any deep sense, and redefining freedom does not change that. Peter van Inwagen's consequence argument puts it formally: if you have no control over the past or the laws, and they entail your action, you have no control over your action.
The reply: Compatibilists answer that 'could have done otherwise' has a sensible meaning they can keep: you would have acted differently if your reasons had been different. And Frankfurt cases suggest that being able to do otherwise may not be what responsibility needs in the first place.
Defended by: David Hume, Thomas Hobbes, Daniel Dennett, Harry Frankfurt

Illusionism

We are not free in the deep sense, but the belief that we are is useful and perhaps should be kept in place.

Best argument: The libertarian kind of freedom does not exist, yet a world in which everyone believed that would lose something valuable: a sense of dignity, effort and accountability. Saul Smilansky argues that illusion here plays a positive role, and that we should be cautious about dismantling it.
Strongest objection: Deliberately maintaining a belief you think is false sits uneasily with honesty, and it treats people as subjects to be managed rather than adults who can handle the truth.
The reply: Illusionists answer that the alternative risks real harm, and that the illusion is not imposed but natural: we are built to experience ourselves as free.
Defended by: Saul Smilansky

Where you stand

Do we have free will?

Choose one to see how people answer.

For the full background, variations and open questions, read the entry: Is free will an illusion?.