Man is said to be a reasoning animal. I do not know why he has not been defined as an affective or feeling animal. Perhaps that which differentiates him from other animals is feeling rather than reason. More often I have seen a cat reason than laugh or weep. Perhaps it weeps or laughs inwardly — but then perhaps, also inwardly, the crab resolves equations of the second degree.

The Tragic Sense of Life (1913) - I : The Man of Flesh and Bone