William of Ockham (1825-1347) is best known in the popular mind for the so-called "Ockham's razor," a common sense idea that we shouldn't just suppose that there are many kinds of beings in the world necessary for explaining our theories. He is, however, also known (for related reasons) as a "nominalist," that is, as someone who thinks that universal notions like "dog" and "tree" do not subsist in reality but only arise in the mind, which compares individual things that are maximally similar—hence, calling those individual things by a given universal name.

He also wrote the highly influential Summa logicae, which outlined a form of logic that was congenial to this outlook (as well as other aspects of his theory of mind and metaphysics). If you ever doubt that there was sophisticated philosophy in the middle ages, crack open Ockham's works, and you will see that he (along with many others) were quite agile minds indeed!

Sophocles was a playwright from Greece. He wrote three plays about Oedipus. Oedipus Rex, also known as Oedipus the King, was the most famous of those plays. Oedipus Rex is probably the most famous Greek tragedies ever written, especially since Sigmund Freud used it as the basis for some of his seminal works of psychology.

Hamlet was a turning point in the writing career of William Shakespeare. Taking an old tale about a Prince of Denmark whose father has mysteriously died and whose uncle has usurped the throne, Shakespeare focused intensely on Hamlet's character and inner drama. The play features many ruminations on philosophy and psychology, which were used in most of Shakespeare's later tragedies.

Aristotle was a Greek scientist and philosopher. Sophocles is most famous for his three Theban plays. Aeschylus wrote The Oresteia trilogy. Aristophanes wrote comedies and Euripedes wrote dramas in Athens.

In the Bible, the books of Exodus through Deuteronomy tell of the departure of the Hebrew people from Egypt. The classic moment in this sojourn is their time at Mount Sinai. This is where the so-called Ten Commandments were said to be presented by God to Moses. Whatever might be the historical accuracy of this overall tale, this is an important fact to know, as the experience of the Hebrew people in the desert was pivotal for their self-identity. This would remain a continuing motif throughout their scriptures as well as in the Christian scriptures as well, which would present Jesus as a kind of second Moses.

During the second half of the 13th century, there were several standard philosophical styles. One was the style of literal commentary, which was used for interpreting the texts of Aristotle and other accepted authorities. In addition, within theological circles, there was the development of the so-called "summae"—lengthier summaries of doctrine, sometimes quite systematic in nature.

These large texts, however, were made up of questions that were written in a style quite peculiar to the Middle Ages, namely that of "disputed questions." These texts would set forth a question, take options "pro" and "con" and then make a conclusion based upon both sides of the question. Sometimes, in shorter works like this, the author would only consider the options that were contrary to his own, helping the reader to understand some possible objections to the text.

This style of disputation was used in many of the treatises that began to be written late in the 13th century and into the 14th. It remained a style that was used especially in Catholic thought for some time. It was, however, most vigorously used as a writing style during this period of the Middle Ages.

(It should be added that there were also short treatises written during this time. They are not, however, the most unique style of writing during the time period.)

The Pre-Socratics are so named merely because of their place in history. They came before Socrates. Socrates is like a "dividing line" for Greek philosophical history! In any case, the Pre-Socratics like Thales and Anaxagoras were interested in the basic elements from which all things were made and how those elements became what we know of in our experience. Other thinkers like Heraclitus and Parmenides were interested in more esoteric questions about being and non-being. In some ways, these thinkers were interested in "metaphysics"—especially Parmenides and Heraclitus. More broadly, the group was interested in cosmology or the way the world is to be understood philosophically. Hence, the best overall category for them is that of "natural philosophy", understanding that all of these terms were coined after the time of the pre-Socratics. With Socrates, philosophy took on a very human-centered and ethical set of concerns.

A rhyme scheme identified by letter describes each rhyme with the same letter. Thus, since the poem's first and third lines rhyme, the first stanza should be marked as ABAB. Because the second stanza has a new rhyming word, the second stanza should be marked CDCD.

The followers of Aristotle were called the "peripatetics", and often his general "school" of philosophy is called "peripatetic" or "peripateticism." This name comes from the one of two sources. On the one hand, his school in Athens had colonnades in which the instruction perhaps occurred. The Greek for "colonnade" is peripatoi. On the other hand, however, it is also said that Aristotle walked while lecturing. The word for "a walker" in Greek is peripatetikos. Hence, he would walk back and forth with his students, lecturing. From this one little habit (or, perhaps, the aforementioned colonnades), there arose a title that was affixed to philosophers for over two millennia!

The philosophy of Plato is known for many things. One of his most famous doctrines is the so-called theory of "Forms" or "Ideas." This refers to the notion that everything in the world "participates" in some kind of universal and separate Idea. Thus, we can only call this or that tree a "tree" because those various individual trees participate in the universal notion of "treeness."

This position is often called "extreme realism" because it supposes that our ideas are so real that they actually exist. It is like there is a kind of "heaven" (loosely speaking) in which the Ideas exist. A radically contrary position is sometimes named "nominalism", which indicates that there are no universal Ideas that are really "out in reality." Instead, a strictly "nominalist" position would state that universal ideas like "tree" and "dog" only exist because we give name to individual things.