First published in 1998. This is Volume X of twenty-two in the Sociology of Social Theory and Methodology series. Written in 1960, this focuses on Baron de Montesquieu the pioneer of the Sociology of Knowledge and the author's wish to correct the widespread conviction that the sociology of knowledge as a whole, and not only the doctrine of ideology, is the child of revolutionary sentiment.

Chapter 1 The Conquest of Cartesianism; Chapter 2 Montesquieu's First Sociology of Knowledge; Chapter 3 The Turn from Rationalism to Realism; Chapter 4 Montesquieu's Basic Doctrine of Man; Chapter 5 Montesquieu's Basic Doctrine of Society; Chapter 6 Montesquieu's Final Sociology of Knowledge: Preliminary Observations; Chapter 7 The Genesis of Ideas: Some Secondary Factors; Chapter 8 The Primary Factors; Chapter 9 The Primary Factors; Chapter 10 The Problem of the Ultimate Determinant; Chapter 11 The Problem of the Mode of Determination; Chapter 12 The Problem of the Degree of Determination; Chapter 13 The Problem of Absolute Truth;