Volume 2 begins with discussion of Aristotle's most significant conclusions, and Caird then turns to an exposition of the general character of post-Aristotelian philosophy, this exposition providing him with a context within which he can investigate the origin and the principles of Stoic philosophy, the Stoic synthesis of pantheism and individualism, the Stoic conception of the chief good, and the Stoic view of practical ethics. These reflections are completed by a lecture describing the transition from stoicism to neo-Platonism. Caird thereafter pays especial attention to two of the most prominent neo-Platonists, Philo of Alexandria and Plotinus. Both the philosophy and the theology of Philo are expounded, before Plotinus takes centre-stage, with chapters devoted to Plotinus in respect of his place in the development of Greek philosophy, with particular reference to the idea of the world-soul as mediator between the intelligible and the sensible worlds, and to the relations in which human beings stand to God. Consideration of these matters lead to an investigation of the controversy between Plotinus and the Gnostics. Volume 2 closes with a final lecture “The influence of Greek philosophy upon Christian theology” in which Caird deals with neo-Platonic discussions on the nature of evil and its relation to the Good.