In the history of these animals we shall not follow the pedantic method of schools, which lays down arbitrary maxims as real, and falsities as truth; such documents are eagerly imbibed by children, but are judiciously rejected by men, if not founded on solid principles. We shall, therefore, to avoid such imaginary methodical distributions, which have been of no other use than to heap a multiplicity, and even distinct species, of animals into one indiscriminate mass. What I call an _Ape_ is an animal with a flat visage, and without a tail, whose teeth, fingers, nails, and hands, resemble those of the human species, and who also walks upright on its two feet. This definition, drawn from the nature of the animal, and its resemblance to man, will exclude every animal that has a tail, or a long snout, crooked or pointed claws, or whose nature obliges them to walk more willingly on four feet than on two. After this fixed and precise rule, let us examine to what animals the name of Ape can properly be applied. The ancients knew only one; the _pithecos_ of the Greeks, and the _simia_ of the Latins, is the real ape, and on which Aristotle, Pliny, and Galen, have instituted all their physical comparisons, and founded all their relations of the ape to mankind. But this ape of the ancients, which so greatly resembles man in its external form, and still more in its internal organization, nevertheless differs from him in an essential point, namely, magnitude. The size of the human species is generally above five feet, while that of the _pithecos_ is seldom more than a fourth of that height. Therefore, if this animal had a still greater resemblance to the human species, the ancients would have had reason to regard it only as an _homunculus_, a dwarf, or a pigmy, capable only of attacking small animals, while man knew how to subdue the elephant, and even to conquer the lion.