"As the ancients themselves knew, Stoicism was not a uniform doctrine. Throughout the centuries there existed factions; the Stoics treasured their independence of judgment and quarreled among themselves." Yet, "despite their individual differences, the Stoic dissenters remained Stoics. That which they had in common, that which made them Stoics, is what I understand as the meaning of Stoicism."

Thus delimiting his framework, Ludwig Edelstein attempts to define Stoicism by grasping the elusive common element that bound together the various factions within the ethical system. He begins this exemplary essay with a description of the Stoic sage—the ideal aimed at by Zeno and his followers—which establishes the basic characteristics of the philosophy. Mr. Edelstein then proceeds to a more detailed examination, discussing the Stoic concepts of nature and living in accord with nature; the internal criticism of the second and first centuries B.C., which indicates the limitations and possibilities inherent in the doctrine; the Stoic's way of life and his attitude toward practical affairs, revealing the values cherished by the adherents of the Stoa; and, finally, the place of Stoicism in the history of philosophy.