Aristotle was the first to classify areas of human knowledge into distinct disciplines and to create a formal system of logical reasoning. His discoveries and works laid the foundation for philosophy, science, and other fields of study that exist today.
Aristotle was born in 384 BCE in Greece. Aristotle was a Greek philosopher and scientist and is now regarded as one of the greatest intellectual figures of Western history. Aristotle moved to Athens after the death of his father in and joined the Academy of Plato, where he stayed for 20 years as Plato's student and colleague. While Aristotle was at the Academy, King Philip waged war on many Greek city-states, though the relations in the Academy seemed to remain cordial. Aristotle started to distance himself from the works and philosophies of his teacher, Plato.
Aristotle’s dialogue, Eudemus, is believed to have been written during his time at the Academy and it reflects Plato's view that a soul is trapped inside the body and is capable of a happier life upon release from the body. Aristotle believed that the dead were happier and more blessed than the living. Another work, the Protrepticus, was reconstructed by scholars from quotations in other works from antiquity. Aristotle believed that everyone should do philosophy and that the best form was contemplating the universe and the nature of it. It is also possible that two more of his works - Topics and Sophistical Refutations - were created during this time. It can be concluded from these works that Aristotle invented the discipline of logic.
Aristotle often wrote about issues with his teacher's works, particularly Plato's theory of Forms. He left Athens when Plato died and went to Assus on the northwestern coast of Anatolia. Aristotle became great friends with the ruler Hermias and married his ward Pythias. Aristotle helped Hermias negotiate an alliance with Macedonia, for which the Persian king killed Hermias in 341 BCE. Aristotle's only surviving poem, Ode to Virtue, was a memorial to Hermias.
Aristotle conducted research in Assus in zoology and marine biology, and continued while he lived in Lesbos. His work was summarized in a book that is known as The History of Animals, to which Aristotle added two short works, On the Parts of Animals and On the Generation of Animals. Some of his observations were not known to have been made again until the invention of the microscope in the 17th century. His work involved the classification of more than 500 animals into genus and species. Where Aristotle lacked evidence, he would readily admit his ignorance and trust observation rather than theory.
Philip II called Aristotle to the capital at Pella to tutor his son - who would come to be known as Alexander the Great. The Rhetoric to Alexander was included in the Aristotelian corpus, though it is now commonly considered a forgery. By the age of 50, Aristotle had established his own school in a gymnasium known as the Lyceum. He built a library and gathered a group of intelligent research students who would study as they walked about, as Aristotle liked to do. Unlike the Academy, Aristotle's Lyceum was not a private club, rather, it was open to the public and free of charge. It is likely that most of Aristotle's works come from this time in his life, though his main works on physics, metaphysics, psychology, ethics, and politics were regularly updated or rewritten. His works were systematic, and he divided the sciences into three categories: productive, (those that have a product such as engineering and architecture), practical, (specifically, ethics and politics), and theoretical, (math, physics, and theology).
Aristotle fled to Chalcis when Alexander died, fearing the same fate as Socrates. He died a year later. Aristotle's will dealt with the provision of his academy and works to his friends and dependents, namely Theophrastus, to whom he left the Lyceum and his own writings. Aristotle's surviving works amount to around one million words, though it is believed that this accounts for only one-fifth of his total output. Aristotle's philosophies and works changed all areas of knowledge, and he was the first to classify areas of knowledge into distinct disciplines - some of which we still use today. He is known as the "father of logic", as he was the first that we know of to develop a formal system of reasoning. His logic - if the premise is true, the conclusion must be true - dominated this area for a couple thousand years.
“We are what we repeatedly do. Excellence, then, is not an act, but a habit.”
“Happiness is the meaning and the purpose of life, the whole aim and end of human existence.”
“It is the mark of an educated mind to be able to entertain a thought without accepting it.”