Why Do We Choose One Thing More Than Another?

Deterministic account says what's going on in the universe is simp atoms obeying physical laws. Emergent complexity, that is to stuff more complex than an atom, but still very much real, like a statue or a person really is important for our account. So let's now consider free will. i want to apply this very argument to free will. Why is it that we choose one thing rather than another? One account is this? The electron or potassium iron, or whatever, goes left rather than right down some ion channel in a neuron, and the neuron fires. And so therefore we end up choosing one thing instead of another. That argument can always be made no matter what