The volume presents a systematic account of ancient Greek philosophical development, beginning with Plato and Aristotle and their treatments of dialectic, nature, and mind, then tracing later Hellenistic schools — Stoicism, Epicureanism, and the New Academy — and the emergence of sceptical argument. It examines metaphysics, physics, psychology, ethics, politics, and logic across thinkers, and concludes with the Neo‑Platonic reception in Alexandria, discussing Philo, Gnostic and cabalistic currents, and figures such as Ammonius Saccas, Plotinus, Porphyry, and Proclus. Emphasis falls on conceptual progression from Socratic insight to systematic philosophical science.