79. Division. -- The characteristic just referred to appears conspicuously in Neo-Platonism, the most interesting and most important philosophy of this period. Neo-Platonism filled the last three centuries of Grecian philosophy. It formulated a powerful synthesis, remarkable for the unity and coherency of its theories. This it is that distinguishes it from the similar systems which led up to it.

These latter imperfectly co-ordinated systems began to appear towards the end of the first century B.C. They influenced Neo-Platonism, and the new spirit lived in them: hence it is preferable to place them in the fourth period of this history, even though chronologically they were contemporary with the eclectic and sceptic systems treated above. We may, therefore, distinguish in the fourth period of Grecian philosophy: (1) the precursors of Neo-Platonism (§ 2); (2) Neo-Platonism itself (§ 3).