Semicompatibilism

Core Idea

Semicompatibilism, developed by John Martin Fischer, holds that moral responsibility is compatible with determinism even if the ability to do otherwise (free will in the traditional sense) is not. Fischer accepts that Frankfurt-style cases show the Principle of Alternate Possibilities is false — an agent can be morally responsible even when she could not have done otherwise. What responsibility requires instead is that the action issue from a mechanism that is the agent's own and that is moderately reasons-responsive: it would respond to at least some rational considerations across a suitable range of scenarios. This view is 'semi' because it remains neutral on whether determinism is compatible with free will understood as the power to do otherwise — it only claims compatibility with moral responsibility. Semicompatibilism thus sidesteps the Consequence Argument by changing the target from freedom to responsibility.

How It's Best Learned

Read Fischer and Ravizza's Responsibility and Control chapter 3 on mechanism ownership and moderate reasons-responsiveness. Then evaluate whether moderate reasons-responsiveness is too weak — could a kleptomaniac's mechanism be moderately reasons-responsive while still being intuitively unfree?

Common Misconceptions

• Semicompatibilism does not claim that we have free will; it claims that moral responsibility does not require free will in the alternate-possibilities sense.
• Reasons-responsiveness is not the same as rationality — an agent can be reasons-responsive (the mechanism would react to some reasons) without being fully rational.

Explainer

You already know compatibilism — the view that free will and determinism can coexist — and you know hard determinism's challenge: if every action is the inevitable result of prior causes, how can anyone be truly free or genuinely responsible? Standard compatibilism responds by redefining freedom in terms of acting without coercion, responding to reasons, or acting from one's own desires. Most versions also hold that freedom requires the ability to do otherwise: you are free only if, under the same circumstances, you could have chosen differently. John Martin Fischer's semicompatibilism abandons this requirement entirely and reconstructs moral responsibility on independent grounds.

The trigger for this move is Frankfurt-style cases. Harry Frankfurt described scenarios in which an agent deliberates and decides independently, but an observer with perfect knowledge would have intervened to ensure she made that choice had she been about to choose otherwise. The agent acts entirely on her own — no intervention occurs — but the intervention would have prevented any alternative. The Principle of Alternate Possibilities (PAP) — "you are morally responsible only if you could have done otherwise" — implies she is not responsible. Frankfurt argues this is wrong: she deliberated freely, her decision was genuinely her own, and the counterfactual intervener never touched her. Therefore PAP is false.

If PAP is false, what *does* moral responsibility require? Fischer's answer is reasons-responsiveness. An agent is responsible when her action issues from a mechanism that is her own — not externally implanted or manipulated — and that mechanism must be moderately reasons-responsive: it would respond to at least some rational considerations across a suitably varied range of scenarios. You do not need to have been able to do otherwise in the actual situation; you need to be the kind of reasoner whose mechanism would have responded *if the reasons had been sufficient*. A compulsive hand-washer might wash her hands in a scenario where no compelling reason not to arises, yet if her mechanism would not have stopped even given decisive reasons, it fails the responsiveness condition and she is not responsible in the relevant sense.

The view is called "semi" because Fischer remains neutral on whether determinism is compatible with the traditional freedom to do otherwise. He accepts that the Consequence Argument — the formal argument from determinism to the conclusion that no one could ever have done otherwise — may be sound. He simply insists that this is the wrong target. Moral responsibility does not require alternate possibilities; it requires that the agent's own reasons-responsive mechanism produced the action. Semicompatibilism thus sidesteps the intractable debate about whether determinism forecloses alternatives and redirects philosophical attention toward the actual psychological and structural conditions under which we hold each other rightly responsible.