Defining Free Will

Skomatth

Following the the logical positivist convention of defining a term in use I am seeking a definition of free will as it occurs in the proposition "[agent]A has free will". This will involve formulating an equivalent proposition which uses no synonyms of "free will".

I believe it can be done in this way: "At any time t, even if all facts are known about A's physical and psychological state, no reliable hypothesis could ever be able to predict A's physical or psychological state at time t+d."

Is this a satisfactory definition?

selfAdjoint

How does this distinguish "freely willed" from random? In general how can you define an inner condition like will in terms of external behavior?

Skomatth

Good point. Do you think free will is an unanalysable concept or could this be defined differently?

Tournesol

You need to add a rider to the effect that the agent's action is nonetheless
rationally comprehensible ie aimed at achieving some purpose.