Perception is what is given in experience. What people do desire is what is given in experience. In both natural and moral philosophy claims must be justified by appeals to experience. Mill appeals to empirical evidence to support his claim that human pleasures include not only pysical pleasures but also the pleasures of the intellect, feelings, imagination and the moral sentiments. Human beings have faculties which enable them to experience these higher pleasures.
Mental pleasures are intrinsically superior to physical pleasures, as well as circumstantially.
The evidence Mill appeals to in support of his claim that there are different kinds of pleasures and that some are superior to others is the experience of mankind. Those who are acquainted with both sorts of pleasures do prefer the higher pleasures. This is MIll's basis for claiming that the Golden Rule is an example of the ethics of utility. The rule that one ought to tell truth has so much utility that it ought not to be overridden for one specific case . Mill recognizes external motives for obeying the principle - avoiding punishment and achieving the esteem of others.