Science is a process, not a static view. It is a method of trying to find out the truth. But there are gaps in scientific knowledge for sure. But just because there's no map for a location yet, that doesn't mean it cannot be mapped.

In order for individuals to have true free will, we would need to be able to make choices free from external factors. That's literally what freedom means. But we know that we are all linked to things outside of us. Every choice we make involves factors and influences external to us. No choice is ever made in a causal vaccuum.