[91] The explanation of the way in which the average rate of profit arises belongs to the fundamental part of the third book of Das Kapital, and Marx must have thought it out together with the fundamental chapters in the first book.
[92] This is the case contemplated by Ricardo in the celebrated § 44 of chapter vi, On Profits: Marx appears to attach little importance to this case, having complete faith in the continued technical progress of agriculture, not to speak of other counteracting causes. It is necessary to add that Marx in conformity with his law, maintains that the rent of land also has a tendency to fall, although it may increase its total amount, or its proportion in reference to industrial profits: see vol. iii, 223-4.
CHAPTER VI. ON THE ECONOMIC PRINCIPLE[ToC]
TWO LETTERS TO PROFESSOR V. PARETO
I
Need for more comprehensive definition of the economic principle: Reasons why the mechanical conception erroneous, economic fact capable of appraisement: Cannot be scale of values for particular action: Economic datum a fact of human activity: Distinction and connection between pleasure and choice: Economic datum a fact of will: Knowledge a necessary presupposition of will: Distinction between technical and economic: Analogy of logic and æsthetic: Complete definition of economic datum.
Esteemed Friend,