Aristotle 
The History of Animals 

The History of Animals is one of the major texts on biology by the ancient Greek philosopher Aristotle, written in the fourth century BC. Seen as a pioneering work of zoology, Aristotle frames his text by explaining that he is investigating the what (the existing facts about animals) prior to establishing the why (the causes of these characteristics). The book is thus an attempt to apply philosophy to part of the natural world.