Aristotle's Zoology

Aristotle was a keen observer of the development of chicks by looking inside eggs at different stages of incubation. He believes that when we are dividing up animals and understanding their functions, we are learning about eternal necessary features of the world. A chick embryo is relentlessly pursuing its final cause, which is to be born as a chick, which can grow into a mature chicken. The preservation of species is of tremendous importance for aristotelian scientist who is interested in necessary and eternal truths.