Darwin conceived the theory of sexual selection in order to explain beauty in animal Kingdom. He hypothesised that most of the male ornaments had been developed to correspond to a female ‘sense of beauty’. His successors developed a theory of mate choice in which the aesthetic sense was left out. The male sexual ornaments were considered as salient cues that evolved because they are indicators of males’ fitness, which stimulate the female to mate. As a consequence “good genes” would spread to future generations. Such a perspective left no place for the males’ appearance and displays as a source of pleasure for females. More recently, authors have considered that male traits might evolve because they make discrimination, stimulus recognition, memorability and learning easier. The winner is the most attractive not necessarily the ‘strongest’ male. Moreover, male traits might be favoured because they happen to fit an already existing bias in the female sensory system. Such a sensory exploitation determines the direction of a “runaway process”. Today, the “aesthetic sense” is back, the neurosciences study the chemistry and circuitry that support pleasure in the brains of humans and animals; social psychology and animal cognition focus on emotions, categorisation and prototype used for mate choice. Animals and humans in order to make a decision, have to evaluate both the sensation and the goal directed action. For this a salient hedonic value has to be built by the mind. Here are the processes involved in the ‘aesthetic judgement’.