A response to a comment by Ian Brown within the question he asked “How does our contemporary understanding of evolutionary biology/psychology, neurophysiology, and embodied cognition impact on our understanding of a priori knowledge?”
Have liked most of your thinking to this point, and there seems to be divergence here.
It seems clear to me that evolution is as you suggest responsible for the a posteriori generation of all seemingly a priori knowledge through the process of sorting by survival in contexts of essentially random variations.
On that much we seem to agree fairly closely.
If one looks at the deeply recursive sets of processes that seem to have produced the very complex set of complex adaptive cooperative systems that are us, and does so from a systems perspective, then we can see new sets of systems being sorted by the specifics of their contexts.
Every level of system requires some sort of set of boundary conditions for it to exist. If there are no boundaries, everything is free to mix, and complexity cannot emerge. Complexity demands some level of boundary to exist.
Looking at this notion of required boundary at the most abstract level one can get to (whatever it happens to be), one will see necessary constraints on freedom (at that and every lower level).
If freedom is to persist in reality, then it must restrict its options to those that are actually survivable.
At higher levels, these appear as constructs like values and ethics and morality. They seem to be the necessary phenotypic expressions of the boundary conditions required for the level of complexity embodied in the particular class of complexity.
And the deeper one pushes that construct, the more abstract the levels of boundary become. For many even the existence of boundary may be beyond the levels of perception and abstraction available; which alters nothing about the necessity of boundaries for survival – and it is a layer of complexity that some will find impenetrable.
The mind bendy recursive bit of this is accepting that there may be infinite sets of constraints about which we are entirely ignorant that are required for the existence of higher levels of complexity about which we have no current knowledge.
Modern physics deals with the very small by equations that express only as probability functions.
At every level it seems that form can be maintained if randomness is both present and sufficiently constrained.
That fact of evolution (the requirement for randomness to deliver variation, and constraints to allow the emergence of complexity) does seem to deliver a very real form of free will, a will that is not entirely formed by the facts of its past, but also incorporates aspects of the random exploration of the possible.
It is not entirely predestined, and it does require influence from the past, and constraints in the present (if it is to survive).
It is not entirely free, and it does incorporate aspects that cannot be predicted from a knowledge of its past.
This does seem to be the sort of free will we have available.
It does seem to be good enough to survive – if we use it wisely to the best of our limited abilities.