Consequence Argument Scenario

The argument

Van Inwagen's reasoning is compressed but precise. Start with two premises almost everyone accepts.

First: you have no control over the laws of nature. You didn't choose them. You can't change them.

Second: you have no control over events that occurred before you were born. You didn't choose the configuration of the universe in 1850, or 1950, or the moment of your birth.

Now add determinism: every event is the inevitable consequence of prior events, operating under fixed laws. If that's true, your actions today are consequences of the laws of nature plus the state of the world before you were born. Since you have no control over either of those, you have no control over their consequences. Including your actions.

Van Inwagen called this the Consequence Argument. If it goes through, compatibilism is false: it's not enough to say you acted from your own desires if those desires were themselves determined by factors entirely outside your control.

The compatibilist response

Compatibilists have several answers. The most common is to challenge what "could have done otherwise" means. When we say someone "could have" done something, we usually mean something conditional: they would have done it if they had chosen differently. That kind of conditional ability is compatible with determinism. The determined agent still acts differently in worlds where their determined desires are different.

Frankfurt's cases support this by suggesting that moral responsibility doesn't require alternative possibilities at all: what matters is whether your action was genuinely your own, not whether the causal history of the universe left an exit open.

Van Inwagen found these responses unconvincing. He thought compatibilists were changing the subject, offering a softer notion of freedom that sounds like what we want but isn't what we actually care about when we ask whether someone deserves blame.

Why van Inwagen remained unsatisfied

Van Inwagen was not a convinced hard determinist. He acknowledged that the Consequence Argument doesn't prove determinism is true, only that if it is, free will is gone. And he took seriously the indeterminist alternatives.

But he also found those unsatisfying. If indeterminism is true and your choices involve genuine randomness, it's not obvious that the randomness helps. A decision partially produced by quantum chance isn't clearly more free than one produced by deterministic causation. It might just be partly arbitrary.

Van Inwagen ended up thinking free will might be incoherent, or at least that we don't have a good theory of what it would take to have it. The Consequence Argument is useful not because it definitively closes the question but because it forces anyone who believes in free will to be precise about what exactly they're defending.