Frankfurt Cases

The scenario

A neuroscientist, Black, wants you to vote for candidate A. He has implanted a device in your brain that monitors your decision-making. If you begin to form an intention to vote for B, the device activates and makes you choose A instead. If you form an intention to vote for A on your own, the device does nothing.

You deliberate, decide you prefer A, and vote for A. The device never activates.

You could not have voted for B. If you had tried, Black's device would have stopped you. But you didn't try. You chose A for your own reasons, through your own reasoning, without any interference. Are you responsible for your vote?

Frankfurt says yes. And if you are, then the Principle of Alternative Possibilities is false: moral responsibility doesn't require the ability to do otherwise.

What this is supposed to refute

The Principle of Alternative Possibilities was almost universally accepted before Frankfurt's paper. It seemed obvious: you can only be blamed for what you could have avoided doing. If you had no choice, you're off the hook.

Frankfurt's case is designed to separate two things that seem inseparable: the absence of alternatives and the absence of responsibility. In the scenario, you lack alternatives (Black's device ensures that). But you also face no interference. Your choice is genuinely your own. The lack of alternatives was never activated. It was waiting, unused, while you freely made the same choice it would have compelled.

If the counterfactual intervention never kicks in, why should its mere existence reduce your responsibility?

The flicker of freedom

The most influential objection is the "flicker of freedom" response. Philosophers like Carl Ginet and David Widerker argue that even in Frankfurt's scenario, there must be some point, however brief, where you could have done otherwise. The device needs some signal to read before it intervenes. If you had begun to form an intention to vote for B, that initial flicker of intention was something that happened freely. And that flicker, small as it is, is all the alternative possibility needed to preserve the principle.

Frankfurt and his defenders have worked to close this gap by constructing variants where the device reads earlier signals, or where it activates on something entirely outside your control. The philosophical literature on these cases is large, precise, and unresolved.

What makes Frankfurt cases philosophically durable isn't that they definitively settle anything. It's that they force you to say exactly what you think alternative possibilities are for, and whether the kind that matter for responsibility require anything more than that your choice was genuinely your own.