No longer did philosophers aspire to the deep spiritual insights and broad moral vision of Socrates, Plato, and Aristotle. They divided into conflicting schools and wandered through the Greco-Roman world as permanent immigrants, picking up tutoring jobs as they could.... the upshot was a debased intellectual climate, fragmented and agnostic.

Ch.VII The Way They Went: Greco-Roman Meets Judeo-Christian - Sailing the Wine-Dark Sea: Why the Greeks Matter (2003)