Free will according to K. Popper

"We are 'free' (or whatever you want to call it), not because we are subject to chance rather than to strict natural laws, but because the progressive rationalization of the world--the attempt to catch the world in the net of knowledge--has limits, at any moment, in the growth of knowledge itself which, of course, is also a process that belongs to the world.

Rational action without foreknowledge--of a scientific, a hypothetical, kind at least---is impossible; and it is this very same foreknowledge which turns out to be so limited as to leave room for action--that is, for 'free' action."

K. Popper, in The Open Universe, section 23.

See my review of his book.