Nicholas Humphrey, “The Illusion of Beauty” in his book of essays, Consciousness Regained: Chapters in the Development of Mind. UK: Oxford University Press, 1984, p. 126—
Here then we have the beginnings of an answer to what relations lie at the heart of beauty. “All beauty may by a metaphor be called rhyme.” What is rhyme like? Well, let us have an example: cat rhymes with mat; cat does not rhyme with table; cat does not rhyme with cat. Taking rhyme as the paradigm of beauty, let us turn at once to the fundamental question: Why do we like the relation that rhyme epitomizes? What is the biological advantage of seeking out rhyming elements in the environment? The answer I propose is this: Considered as a biological phenomenon, esthetic preferences stem from a predisposition among animals and men to seek out experiences through which they may learn to classify the objects in the world around them. Beautiful “structures” in nature or in art are those which facilitate the task of classification by presenting evidence of the “taxonomic” relations between things in a way which is informative and easy to grasp.