… except that the brain itself is a machine, a network of cells that computes its choices….

If you start by asserting that this metaphor is simply the fact of the matter, your subsequent argument rests on quicksand. If you are right about the centrality of “the complex circulation of molecular information,” you should address why virtually none of our actual computing machines work by circulating “molecular information.”

If men were solely driven by their pleasures and pains, women would have centuries ago taken total control of men’s minds. Really addressing the question of free will doesn’t consist in showing the neural correlates of the “pleasure principle,” but rather in showing how conscious human beings are so often (even if not all or most of the time) capable of transcending it.

Answering that question would produce a plausible model of free will. Denying the question of transcendence – claiming that all behavior is merely the end result of calculation against projected sum results of an equation of pleasure and pain – misses the question of free will entirely.

It’s also simply incoherent. It assumes that all pleasures can be neatly mapped onto an intensity scale. Yet any aesthete knows that subtle pleasures can be preferable to strong pleasures, and that the flavors and complexities of pleasures can hardly be reduced to a scale at all – or even multiple scales. To the extent different pleasures – say of fine food or fine scenery – can be scaled, it’s not to the same scales across pleasure kinds either. Nor are pains differentiated simply in linear intensity.