Although there are several letters attributed to Plato, the bulk of his works are written in the form of dialogues. In his philosophical works, he often writes of how Socrates disputes and discusses some matter with various figures of Athenian civic life. The dialogue style itself is masterful, often using literary devices to make subtle philosophical points. In this, he differs greatly from his student, Aristotle, whose works are quite dry (though also much more direct and clear than are Plato's works). Many later philosophers would write in the form of dialogues, though it is arguable that few ever matched the excellence of Plato's style.

In the Confessions, Augustine of Hippo pens a story of his conversion to Christianity. In this, he does "confess" his guilt and arrival at conversion from this guilty state of life. The whole work is written like a monologue to God—a long prayer. This is not offered as an option among those provided for this question. Instead, the closest genre here noted is that of autobiography. In a general way of speaking, Augustine does pen an autobiography by writing the Confessions. It does tell his life story up to a certain point in history, thus giving us a form of monologue-to-God-biography.

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.

Throughout the writings of Plato, we are presented with an image of Socrates as a disputant, constantly arguing with a group of philosophers known as the "sophists." The word "sophist" actually comes from the same roots as "philosophy," though the meaning is interesting—and quite telling about what had so angered Socrates. "Philosophy" literally means "love of wisdom." A "sophist" is someone who appears to be wise—but in fact is not. This is quite the vexing issue for Socrates. There are people who have the appearance of wisdom but in fact are not. Thus, in many of the dialogues, he is presented as arguing against this kind of sophistry. It is also for this reason that he expresses concerns about people who make images and write poetry. Such people seem to be just like sophists—who make bad arguments appear like they are good ones.

Suetonius is most famous for his history of the Roman Empire, De Vita Caesarum, widely known in English as The Twelve Caesars. Marcus Aurelius was an Emperor himself, also known for his philosophical work, The Meditations. Juvenal and Plautus were Roman comedy authors, while Aeschylus was a Greek playwright.

Plato's works were largely written as dialogues, conversations between two different thinkers on a weighty topic. In most of the dialogues, the key figure was Plato's teacher, Socrates. Socrates is considered one of the leading progenitors of Western philosophy, largely thanks to the writings of Plato.

While all the Roman Emperors read philosophy and a few others wrote literary works, only Marcus Aurelius, emperor from 161-180 CE, actually wrote a philosophical tract, known as The Meditations. Marcus Aurelius' Meditations were a development on Stoic philosophy, and the work is really a collection of thoughts and quotations compiled while Marcus Aurelius was Emperor and leading the Roman Army on campaigns.

De Oratore was considered a model of how to conduct rhetoric and oratory, not only in the ancient world, but throughout European history into the Renaissance. Its author, Cicero, became widely beloved in the Middle Ages and beyond for his philosophical focus on the engaged moral and noble man.

The three great Greek philosophers are uniquely tied together, through a series of teacher-student relationships. Socrates, the great founder of Greek philosophy, directly taught Plato, who recorded most of Socrates' thought. Plato then taught Aristotle himself, which makes the entire chain of Greek philosophy tied to all three.

Located in his work The Republic, the allegory of the cave is one of the most famous ideas associated with the Greek philosopher Plato. Taking place in a dialogue with Socrates, the allegory describes people chained inside a cave, forced to watch only the images projected by shadows on the cave wall and assuming this is reality. Plato has Socrates assert that a philosopher's role is to bring people out of the cave and into reality by destroying what they assumed by only watching the shadows in the cave.