In developing his own theories on capitalism and society, Karl Marx was heavily influence by the phenomenology of Georg Wilhelm Friedrich Hegel. In particular, Marx used Hegel's dialectic, which stressed that any idea unfolds along a three part process. First, a thesis is presented, which leads to a reaction in the form an antithesis, which is combined with the thesis in a resolution called the synthesis.

Augustine's Confessions follows the life of the author from his birth through thirteen separate books. Primarily the story of Augustine's early spiritual and educational life and his eventual conversion to Christianity, the book nonetheless covers the important details of Augustine's life. This makes the Confessions one of the earliest examples of an autobiography.

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.

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 "Hegelian dialectic" is often rendered as Thesis-Antithesis-Synthesis, meaning any statement can be opposed by an opposite idea, and the clash of the two ideas will create a better philosophical statement. Hegel preferred the terms "abstract," "negative," and "concrete," which better explained the ideas' relationship. Hegel's dialectic was widely influential; it was used by thinkers like Karl Marx and argued against by philosophers such as Søren Kierkegaard and Friedrich Nietzsche.