From: Michael H. Hart, The 100: A Ranking of the Most Influential Persons in History, Hart Publishing Company, New York City (1978), pages 105-109:
Aristotle was the greatest philosopher and scientist of the ancient world. He originated the study of formal logic, enriched almost every branch of philosophy, and made numerous contributions to science.
Many of Aristotle's ideas are outmoded today. But far more important than any of his individual theories is the rational approach underlying his work. Implicit in Aristotle's writings is the attitude that every aspect of human life and society may be an appropriate object of thought and analysis; the notion that the universe is not controlled by blind chance, by magic, or by the whims of capricious deities, but that its behavior is subject to rational laws; the belief that it is worthwhile for human beings to conduct a systematic inquiry into every aspect of the natural world; and the conviction that we should utilize both empirical observations and logical reasoning in forming our conclusions. This set of attitudes--which is contrary to traditionalism, superstition, and mysticism--has profoundly influenced Western civilization.
Aristotle was born in 384 B.C., in the town of Stagira, in Macedonia... At seventeen, Aristotle went to Athens to study in the Academy of Plato. He remained there for twenty years, until shortly after Plato died. From his father, Aristotle may have gained an interest in biology and in "practical science"; under Plato he cultivated an interest in philosophical speculation.
[page 106] ...When Alexander died, in 323 B.C., the anti-Macedonian factions gained control in Athens, and Aristotle was indicted for "impiety." Aristotle, recalling the fate of Socrates seventy-six year earlier, fled the city, saying that he would not give Athens a second chance to sin against philosophy. He died in exile a few months later, in 322 B.C., at the age of sixty-two...
[page 108] Aristotle... was an original philosopher, and made major contributions to every area of speculative philosophy. He wrote on ethics and on metaphysics, on psychology and on economics, on theology and on politics, on rhetoric and on aesthetics...
Perhaps most important of all was his work on the theory of logic, and Aristotle is generally considered the founder of this important branch of philosophy. It was indeed the logical nature of his mind that enabled Aristotle to make contributions to so many fields... Never mystical and never an extremist, Aristotle is consistently the voice of practical common sense. He made mistakes, of course, but what is surprising is how few times in his vast encyclopedia of thought Aristotle made foolish errors.
Aristotle's influence upon all later Western thought has been immense. During ancient and medieval times, his works were translated into Latin, Syriac, Arabic, Italian, French, Hebrew, German, and English. The later Greek writers studied and admired his works, and so did Byzantine philosophers. His work was a major influence on Islamic philosophy, and for centuries his writings dominated European thought. Averroes, perhaps the most famous of all Arab philosophers, attempted to create a synthesis of Islamic theology and Aristotelian rationalism. Maimonides, the most influential of medieval Jewish thinkers, achieved a similar synthesis for Judaism. But the most celebrated such work was the great Summa Theologica of the Christian scholar, St. Thomas Aquinas. Far too many medieval scholars were deeply influenced by Aristotle to list them all.
Admiration for Aristotle became so great in late medieval times it approached idolatry, and his writings became a kind of intellectual straight jacket, inhibiting further inquiry, rather than a lamp to light the way. Aristotle, who liked to observe and think for himself, would doubtless have disapproved of the blind adulation that later generations gave to his writings.
[page 109] Some of Aristotle's ideas seem extremely reactionary by today's standards. For example, he supported slavery as being in accord with natural law, and he believed in the natural inferiority of women. (Both of these ideas, of course, reflected the prevailing views of his time.) However, many of Aristotle's views were strikingly modern, e.g., "Poverty is the parent of revolution and crime," and "All who have meditated on the art of governing mankind are convinced that the fate of empires depends on the education of youth." (There was, of course, no public education at the time that Aristotle lived.)