The opening of Chapter I
OUTLINE OF THE HISTORY OF THE FRENCH INTELLECT FROM THE MIDDLE OF THE SIXTEENTH CENTURY TO THE ACCESSION TO POWER OF LOUIS XIV.
The consideration of these great changes in the English mind, has led me into a digression, which, so far from being foreign to the design of this Introduction, is absolutely necessary for a right understanding of it. In this, as in many other respects, there is a marked analogy between investigations concerning the structure of society and investigations concerning the human body. Thus, it has been found, that the best way of arriving at a theory of disease is by beginning with the theory of health; and that the foundation of all sound pathology must be first sought in an observation, not of the abnormal, but of the normal functions of life.