The works in the Central Works of Philosophy volumes have been chosen because of their fundamental importance in the history of philosophy and for the development of human thought. Other works might have been chosen; however, the underlying idea is that if any works should be chosen, then these certainly should be. In the cases where the work is a philosopher's magnum opus the essay on it gives an excellent overview of the philosopher's thought.

Chapter 1 by Hugh Benson presents the central theme of Plato's Republic, that of the nature of justice. The Republic stands as arguably the most important work of Western philosophy. It is a pivotal work in Plato's thought, presenting a well worked out culmination of previous ideas, following which he subjected those ideas to considerable critical analysis, although he did not abandon them.

Chapter 2 by Paula Gottlieb discusses Aristotle's Nichomachean Ethics, central to understanding the key Greek idea in ethics of eudaimonia, usually translated “happiness”. However, happiness here refers not to a subjective state of pleasure, but to aretē or virtue, whereby our actions should be guided by what truly contributes to our well-being or excellence as the kind of creatures that we are.

Chapter 3 by Harry Lesser gives an account of Lucretius's On The Nature of the Universe, which takes the form – not unusual for the time – of an extended philosophical verse.