AT THE END of the last chapter, I explained the meaning of the diagram I borrowed from Pareto's Treatise, a diagram that is designed to illustrate the relations between the expression, C, which we know directly, the act, B, which we can observe from the outside, and the state of mind, A, which we infer from expressions and acts.
The more complex diagram now set beside it takes account not only of state of mind and expression, A and C, but also of two other factors: creed, which we shall call B, and act, which now becomes D.
Reciprocal relations exist between expressions, creed, and acts. Creed may exercise an influence upon theories by reinforcing the convictions of those who practice it, as I have remarked. Creed may also exercise an influence upon acts—the diagram becomes more complicated, but the fundamental idea remains the same. Nonlogical actions are presented to us in a threefold form: acts; theories which justify