 The argument for the desirability of happiness is, like the rest of Mill’s philosophy, naturalistic in orientation. As was observed above  (section 2.1),  Mill’s naturalism leads him to the claim that we cannot have any knowledge by intuition. His claim that the “sole evidence” it is possible to produce for normative claims about desirability are empirical observations about what people “do actually desire” must be seen in the context of this basic commitment—our knowledge of the desirable cannot be anchored by direct a priori insight into the nature of the good, and as such can only come by way of critical examination of what human beings do actually take as good.