[[Categoria:Pagine che usano RigaIntestazione|Scientia - Vol. IX.djvu{{padleft:397|3|0]]all other attempts at explanation, is so unconsciously presupposed. For when any other goods than enjoyable income are considered, their values already imply a rate of interest.

But we have not yet wholly solved the problem of interest. It is not enough to know that the more impatient a people are, the higher will be their rate of interest, and that the more patient they are, the lower will be their rate of interest. We must also know on what causes the rate of impatience depends. It depends principally upon two circumstances, the character of the individual and the character of the income of which he finds himself the owner.

It is clear that the rate of impatience; which corresponds to a specific income-stream will not be the same for everybody. One man may have a rate of impatience of 5 per cent and another a rate of impatience of 10 per cent, although both have the same income. The difference will be due to the personal characteristics of the individuals. These characteristics are chiefly Ave in number: (1) foresight, (2) self-control, (3) habit, (4) expectation of life, (5) love for posterity. We shall take these up in order.

1) First, as to foresight. Generally speaking, the greater the foresight, the less the rate of impatience, and vice versa. in the case of primitive races and instructed classes of society, the future is seldom considered in its true proportions. The story is told of a Southern negro that he would not mend his leaky roof when it was raining, for fear of getting more wet, nor when it was not raining, because he did not then need shelter. Among such persons the rate of impatience for present gratification is powerful because their comprehension of the future is weak. If we compare the Scotch and the Irish, we will find a contrast in this respect. The Irish, in general, lack foresight and are improvident, and the Scotch have foresight and are provident. Consequently the rate of interest is high in Ireland and low in Scotland.

These differences in degrees of foresight produce corresponding differences in the dependence of impatience on the character of income. Thus, for a given income, say 1000 dollars