Berkeley uses the Socratic mode of inquiry in Three Dialogues Between Hylas and Philonous to question fundamental beliefs about knowledge and reality. These dialogues are between Hylas (whose name is derived from the ancient Greek word for matter) and Philonous, whose name means "lover of mind". The new physical sciences developed in the 17th century supported the materialism proposed by Thomas Hobbes and several other philosophers.

Sir Francis Bacon, sometimes known as the father of empiricism, was one of the major political figures of his day, his career culminating as Lord Chancellor under King James I in 1617. Bacon wrote widely, but it is the Essays (published in its third edition in 1625, the year before his death) for which he is best known. Deftly written and often displaying a cutting wit, they cover a wide range of subjects including death, love, marriage, ambition and atheism.

Gorgias of Leontini, a famous teacher of rhetoric, has come to Athens to recruit students, promising to teach them how to become leaders in politics and business. A group has gathered at Callicles' house to hear Gorgias demonstrate the power of his art. This dialogue blends comic and serious discussion of the best life, providing a penetrating examination of ethics.

Laches, a general in the Athenian army, saw Socrates fight bravely in the battle of Delium. When he and Nicias, another general, are asked to explain the idea of courage, they are at a loss, and words fail them. How does courage differ from thoughtless and reckless audacity? Can a lion be said to be courageous? What about small children who have little idea of the dangers they face? Should we call people courageous who do not know whether their bravery will produce good or bad consequences?

Hippias of Elis travels throughout the Greek world practicing and teaching the art of making beautiful speeches. On a rare visit to Athens, he meets Socrates, who questions him about the nature of his art. Socrates is especially curious about how Hippias would define beauty. They agree that beauty makes all beautiful things beautiful, but when Socrates presses him to say precisely what he means, Hippias is unable to deliver such a definition.