Man is no new-begot child of the ape, bred of a struggle for existence upon brutish lines—nor should the belief that such is his origin, oft dinned into his ears by scientists, influence his conduct. Were he to regard himself as an extremely ancient type, distinguished chiefly by the qualities of his mind, and to look upon the existing Primates as the failures of his line, as his misguided and brutish collaterals, rather than as his ancestors, I think it would be something gained for the ethical outlook of Homo—and also it would be consistent with present knowledge.

Primates stand at a turning point in the course of evolution. Primates are to the biologist what viruses are to the biochemist. They can be analysed and partly understood according to the rules of a simpler discipline, but they also present another level of complexity: viruses are living chemicals, and primates are animals who love and hate and think.