Plato: Plato: The Written and Unwritten Doctrines

The author emphasizes the valuable use of Platonic notions and methods by the Neoplatonists and the Schoolmen as well as by such modern thinkers as Husserl and Russell. He also censures, as a great misinterpretation, the widespread Aristotelian view of Platonism as a two-world theory, and argues that, for Plato, the Ideas and their Principles alone have full reality, everything else being logically parasitic upon them.

The work also includes two important Appendices, the first providing translations of the Aristotelian and other ancient material regarding Plato's oral teaching, the second criticizing and refuting the views of Harold F. Cherniss on the same material.