A quick note on Bergson: He believes in free will, funnily enough I don't. What I agree with him on is that existence is a moving thing that cannot be reduced to simplistic parts. He uses an example of making a choice between two paths, to demonstrate that the decision cannot be isolated and cut up metaphysically. What I take from this in my own view is that there is a mixture of elements that make up consciousness and the world that cannot be divided up/reduced to simple points, like I believe the kalam argument does as a predicate.
To explain, I'll use an example of me throwing a stone into a lake. Part of the cause of that event is me. Part of the cause of it however is the nature of the world that leads me to do so out of curiosity or interest. There are other factors that "trim away" (so to speak) at outcomes. If I believed that throwing the stone would cause harm, I'd be much less likely to do so. I'd be compelled by my conscience, I guess. This is an example of me making a choice without having free will. The idea of choice implies a lack of fatalism, and the steering of something indeterminate into solidity. I also have an influence on my environment. I cannot however change who I am as a creature however, and that has nothing to do with chemicals or reductionism. It has to do with reality as a whole, as far as I can see.