St. George Stock authored the Guide to Stoicism, also published as A Little Book on Stoicism. Stoicism was a school of Hellenistic philosophy founded in Athens by Zeno of Citium in the early 3rd century BC. The Stoics considered destructive emotions to be the result of errors in judgment, and that a sage, or person of "moral and intellectual perfection," would not undergo such emotions. Stoics were concerned with the active relationship between cosmic determinism and human freedom, and the belief that it is virtuous to maintain a will (called prohairesis) that is in accord with nature. If you strip Stoicism of its paradoxes and its willful misuse of language, what is left is simply the moral philosophy of Socrates, Plato and Aristotle, dashed with the physics of Heraclitus. Stoicism was not so much a new doctrine as the form under which the old Greek philosophy finally presented itself to the world at large. It owed its popularity in some measure to its extravagance.

A great deal might be said about Stoicism as a religion and about the part it played in the formation of Christianity but these subjects were excluded by the plan of this volume which was to present a sketch of the Stoic doctrine based on the original authorities.