Esthetic pleasure derives pleasure in contemplating something. This pleasure could be sensory, like the enjoyment one derives from looking at a painting or listening to music. Or it could be intellectual, like the pleasure of reading the latest Eckart Tolle. In both cases, pleasure in contemplation must be distinguished from wanting an object for other uses.

Immanuel Kant in the 18th century was among the first to understand this. He used the example of a palace. You might long to live in it, or you might hate it for its extravagance and want to destroy it. But both of these responses are distinct from the pleasure or displeasure derived from merely looking at it. Only the latter pleasure counts as aesthetic.

Discussing sexual selection, Charles Darwin wrote: ‘When we behold a male bird elaborately displaying his graceful plumes or splendid colours before the female … it is impossible to doubt that she admires the beauty of her male partner.’

Assuming that he really means beauty, and not sexual attractiveness, this is a mistake. It confuses sexual desire with aesthetic admiration. According to Darwin’s own theory, when a female looks at a male that way, she is not getting pleasure from looking at him for the sake of looking at him; rather, she is driven to mate with him. Darwin wrongly equates the lustful gaze with simple looking. Kant’s point was that aesthetic appreciation is disinterested. It is pleasure just in looking.