In this section, the first of the chapter, the author, Sir John Hicks, notes that his discussion of interest has concluded, and that he has thereby "concluded all that it is absolutely necessary to say about the foundations of dynamic economics." He further notes his intention, ultimately, "to analyse the working of the dynamic system, proceeding on parallel lines to those on which we analysed the working of the static system in Part II." Meanwhile, he notes a possible objection to the discussion so far, namely that it has not addressed topics such as Income, Saving, Depreciation, or "Investment (with a capital I)."
He explains that he deliberately omitted these concepts from the previous five chapters. He finds "far too much equivocation in their meaning" and believes essentially that "they are not logical categories at all; they are rough approximations, used by the businessman to steer himself through the bewildering changes of situation which confront him."
He states that "eminent authorities" have confused "each other and even themselves, by adopting different definitions of saving and income, none quite consistent, none quite satisfactory." He concludes the section by noting the need to bring out the reason for such confusion. He will spend the remainder of this chapter discussing various definitions of income. In supplementary notes at the end of the chapter he will discuss the relation between Saving and Investment, as well as the effect of interest rate changes on the calculation of Depreciation, and hence Income.
