Aristotle*Considered the father of life sciences. *He was the tutor of Alexander the Great. *Undertook the classification of animals and plants at a large scale. *His main discovery in embryology was that the mother's contribution is as important as the father's. *Believed that the Earth was static and at the center of the universe. He also believed, erroneously, that motion was due to the tendency of all objects to reach there natural state. *He discovered that free fall is an accelerated form of motion, but also believed that heavier objects fall faster than lighter ones. *He considered chemical elements, which cannot be decomposed, to be the constituents of all bodies

•Born: 384 B.C. •Birthplace: Stagira, Macedonia (now Greece) •Died: 322 B.C. •Best Known As: The author of Ethics Aristotle is one of the "big three" in ancient Greek philosophy, along with Plato and Socrates. (Socrates taught Plato, who in turn instructed Aristotle.) Aristotle spent nearly 20 years at Plato's Academy, first as a student and then as a teacher. After Plato's death he traveled widely and educated a famous pupil, Alexander the Great, the Macedonian who nearly conquered the world. Later Aristotle began his own school in Athens, known as the Lyceum. Aristotle is known for his carefully detailed observations about nature and the physical world, which laid the groundwork for the modern study of biology. Among his works are the texts Physics, Metaphysics, Rhetoric and Ethics. He was succeeded at the Lyceum by his student Theophrastus.

Early Life*Born at Stagira in northern Greece, Aristotle was the most notable product of the educational program devised by Plato; he spent twenty years of his life studying at the Academy. *When Plato died, Aristotle returned to his native Macedonia, where he is supposed to have participated in the education of Philip's son, Alexander (the Great). *He came back to Athens with Alexander's approval in 335 and established his own school at the Lyceum, spending most of the rest of his life engaged there in research, teaching, and writing.

*His students acquired the name "peripatetics" from the master's habit of strolling about as he taught. *Although the surviving works of Aristotle probably represent only a fragment of the whole, they include his investigations of an amazing range of subjects, from logic, philosophy, and ethics to physics, biology, psychology, politics, and rhetoric. *Aristotle appears to have thought through his views as he wrote, returning to significant issues at different stages of his own development.

*The aim of Aristotle's logical essays was to develop a universal method of reasoning by means of which it would be possible to learn everything there is to know about reality. *Thus, the Categories proposes a scheme for the description of particular things in terms of their properties, states, and activities. *On Interpretation, Prior Analytics, and Posterior Analytics examine the nature of logical reading, outlining the system of syllogistic reasoning from true propositions that later came to be known as categorical logic.

*Though not strictly one of the logical works, the “Physics” contributes to the universal method by distinguishing among the four causes which may be used to explain everything, with special concern for why things are the way they are and the apparent role of chance in the operation of the world. *In other essays, Aristotle applied this method, with its characteristic emphasis on teleological explanation, to astronomical and biological explorations of the natural world.

*In “Metaphysics”, Aristotle tried to justify the entire enterprise by grounding it all in an abstract study of being. *Although Aristotle rejected the Platonic theory of forms, he defended his own vision of ultimate reality, including the eternal existence of substance. *On “The Soul” uses the notion of a hylomorphic (identifies matter with the first cause of the universe) composite to provide a detailed account of the functions exhibited by living things—vegetable, animal, and human—and explains the use of sensation and reason to achieve genuine knowledge.

Demonstrative Science*In the “Prior Analytics and Posterior Analytics”, Aristotle offered a detailed account of the demonstrative reasoning required to substantiate theoretical knowledge. *Using mathematics as a model, Aristotle presumed that all such knowledge must be derived from what is already known. *Thus, the process of reasoning by syllogism employs a formal definition of validity that permits the deduction of new truths from established principles. *The goal is to provide an account of why things happen the way they do, based solely upon what we already know.

*In order to achieve genuine necessity, this demonstrative science must be focused on the essences rather than the accidents of things, on what is "true of any case as such," rather than on what happens to be "true of each case in fact." *It's not enough to know that it rained today; we must be able to figure out the general meteorological conditions under which rain is inevitable. *When we reason from necessary universal and affirmative propositions about the essential features of things while assuming as little as possible, the resulting body of knowledge will truly deserve the name of science.

The Four Causes Applying the principles developed in his logical treatises, Aristotle offered a general account of the operation of individual substances in the natural world. He drew a significant distinction between things of two sorts: those that move only when moved by something else and those that are capable of moving themselves. In separate treatises, Aristotle not only proposed a proper description of things of each sort but also attempted to explain why they function as they do.

The Four Causes:Aristotle proposed that we employ four very different kinds of explanatory principle to the question of why a thing is, the four causes: 1. The material cause is the basic stuff out of which the thing is made. The material cause of a house, for example, would include the wood, metal, glass, and other building materials used in its construction. All of these things belong in an explanation of the house because it could not exist unless they were present in its composition.

2. The formal cause is the pattern or essence in conformity with which these materials are assembled. Thus, the formal cause of our exemplary house would be the sort of thing that is represented on a blueprint of its design. This, too, is part of the explanation of the house, since its materials would be only a pile of rubble (or a different house) if they were not put together in this way.

3. The efficient cause is the agent or force immediately responsible for bringing this matter and that form together in the production of the thing. Thus, the efficient cause of the house would include the carpenters, masons, plumbers, and other workers who used these materials to build the house in accordance with the blueprint for its construction. Clearly the house would not be what it is without their contribution.

4. Lastly, the final cause is the end or purpose for which a thing exists, so the final cause of our house would be to provide shelter for human beings. This is part of the explanation of the house's existence because it would never have been built unless someone needed it as a place to live.

*Aristotle was one of the greatest thinkers of ancient western civilization. *He was a biologist, a zoologist, a political scientist, a master of logic and rhetoric, an ethicist and a theoretician in physics and metaphysics. *Aristotle synthesized knowledge in many fields, developing a coherent system of understanding. *His mind was expansive and his writings prodigious. His work was considered authoritative not only in ancient times but through the medieval era as well.

*However even today, his thought has continued to exert a strong influence, although admittedly our knowledge and understanding, particularly in the scientific realm, have advanced beyond his. *Nevertheless, it remains a remarkable achievement to have had such a prominent presence over the course of 2500 years.

*Aristotle was meticulous in his scientific work. For example, he was one of the first to collect plant specimens, classify them according to observed characteristics and categorize them. *His approach was so careful and methodical that it became the standard for future scientific work. Perhaps more importantly, Aristotle developed a philosophy of science. He gave us the categories in which to think He attempted to find ground between the position of Plato (who believed that the real world exists in the realm of the Forms; this present world is but a shadowy copy of it) and the atomists (who believed that real world was senseless matter). *Aristotle wanted us to discover the meaning of the good life in this world - that it was real, that it was understandable by our senses and that it was worth knowing.

Aristotle’s Quotes:

All human actions have one or more of these seven causes: chance, nature, compulsions, habit, reason, passion, desire.

All men by nature desire knowledge.

All virtue is summed up in dealing justly.

Anybody can become angry - that is easy, but to be angry with the right person and to the right degree and at the right time and for the right purpose, and in the right way - that is not within everybody's power and is not easy.