Synthesized answer
The provided passages do not contain information about the central thesis of "Principia Metaphysica (with Bernard Linsky)". The passages only include the title and categories of a different text, "Procedures and Metaphysics by Edward William Strong" [Passage 1].
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: Procedures and Metaphysics by Edward William Strong Categories: Mathematics