Aristotle topped another of this lister’s lists, heading the category of philosophy, so his rank on this one is not entirely surprising. But consider that Aristotle is the first to have written systems by which to understand and criticize everything from pure logic to ethics, politics, literature, even science.

He theorized that there are four “causes”, or qualities, of any thing in existence: the material cause, which is what the subject is made of; the formal cause, or the arrangement of the subject’s material; the effective cause, the creator of the thing; and the final cause, which is the purpose for
which a subject exists.

In 343 Aristotle was invited back to Macedonia by the King to tutor the young Alexander. The differing ambitions of the two friends (teacher and student), made for an intense scholarly relationship.

Aristotle is also the first person in Western history to argue that there is a hierarchy to all life in the Universe; that because Nature never did anything unnecessary as he observed, then in the same way, this animal is in charge of that animal, and likewise with plants and animals together. His so-called “ladder of life” has eleven rungs, at the top of which are humans. The Medieval Christian theorists ran with this idea, extrapolating it to the hierarchy of God with Man, including angels. Thus, the angelic hierarchy of Catholicism, usually thought as a purely Catholic notion, stems from Aristotle, who lived and died before Jesus was born. Aristotle was, in fact, at the very heart of the classical education system used through the Medieval western world.

King Philip of Macedonia invited Aristotle to the capitol around 343 BC to tutor his thirteen-ear-old don, Alexander. Tutoring Alexander in the Academy in Assos, Aristotle still remained the president of the Academy. In 359 BC, Alexander's father, King Philip decided to set off to subdue the Greek city-states, and left Alexander in charge, thus stopping Aristotle's tutoring of Alexander.

Although Aristotle does not appear to have made any new discoveries in mathematics, he is important in the development of mathematics. As Heath explains in

"The importance of a proper understanding of the mathematics in Aristotle lies principally in the fact that most of his illustrations of scientific method are taken from mathematics."

Clearly Aristotle had a thorough grasp of elementary mathematics and believed mathematics to have great importance as one of three theoretical sciences. However, it is fair to say that he did not agree with Plato, who elevated mathematics to such a prominent place of study that there was little room for the range of sciences studied by Aristotle. The other two theoretical sciences, Aristotle claimed, were (using modern terminology) philosophy and theoretical physics.

In 335 BC, Aristotle returned to Athens. Speusippus had died, but Aristotle was again not given the presidency of the Academy in Athens, instead, it was given to one of his colleagues Xenocrates. So, Aristotle founded his own school this time, it was named the Lyceum, named after Apollo Lyceus. In 323 BC, twelve years after founding the Lyceum, Alexander the Great died. In Greece resentment against the Macedonia hegemony seethed and riots broke out. Aristotle was accused of impiety, and his life become in serious jeopardy. 

So he left Athens, and went to his late mother's estate at Chalcis on the island of Euboea. He died there in the next year, 322 BC.