The whole of the Western rationalist tradition is doomed because it rests on the faith that 'through science humankind can know truth - and so be free'. But, Gray argues, 'if Darwin's theory of natural selection is true this is impossible'. Drawinian processes are driven, not by the need to ascertain the truth, but to survive and reproduce. Accordingly, 'the human mind serves evolutionary success, not truth.' Indeed, 'in the struggle for life, a taste for truth is a luxury', even a 'disability'. Science, Gray suggests, reveals that 'humans cannot be other than irrational'.
But science itself is a product of our poor, befuddled, irrational, Stone Age minds. If we cannot trust such minds to discover truths about the world, how can we accept the verities of science - including the theory of evolution? The logic of Gray's argument undermines our confidence in its own veracity. For if we are just another animal, then we cannot place any trust in the claim that we are just another animal. Far from science revealing humans to be beings without consciousness and agency, we are only able to do science because of our ability to transcend our evolutionary heritage, to act as subjects, rather than as objects.