Books VIII-X: How various species of animals are nourished, how they migrate, where they nest. Diseases. Differences of animals by region. Character of animals. Which animals are enemies to each other. Observations regarding human development.

Aristotle, son of the physician Nicomachus, was born in Stagira in 384 BC. There is little information about his early years. At the age of seventeen, he went to Athens to attend the Platonic Academy. He remained there for twenty years, from 367 to 348 BC, when Plato died. Then Aristotle left for Assos in Troas and after a three-year stay there, he went to Lesbos and then to Macedonia, where he took on the education of the royal child Alexander.

When his student ascended to the throne, Aristotle settled in Athens and established his school, the Lyceum. After Alexander's death (323 BC), the philosopher's stay in Athens became difficult. He was forced to flee to Chalcis, his mother's homeland, where he died in 322.

A universal mind, Aristotle created an extensive and valuable philosophical and scientific work. Epistemology, logic, theology, physics, biology, psychology, ethics, political philosophy, aesthetics are the main fields of knowledge that he explored and studied. The Alexandrian Hermippus estimated Aristotle's works at 400. Lists that include 143 titles of his works have survived to this day. Diogenes Laertius estimated the number of lines in Aristotle's writings to be 440,000. The influence of his work on the shaping of world thought was, for centuries, and remains, strong.