His intellectual knowledge ranged from every known field of science and arts of that era. His writing includes work in physics, chemistry, biology, zoology, botany, psychology, political theory, logic, metaphysics, history, literary theory, and rhetoric. One of his greatest achievements was formulating a finished system also known as Aristotelian syllogistic. His other significant contribution was towards the development of zoology. It is true that Aristotle’s Zoology is now obsolete but his work and contribution was unchallenged till the 19th century. His contribution towards almost all subjects on earth and its influence makes him one of the most famous and top personalities of all time.