Thus, as the amount of net product marks the progress of wealth, interest on capital, without which net product would be useless and would not even exist, marks the progress of comfort. Whatever the form of government which may be established among men; whether they live in monopoly or in communism; whether each laborer keeps his account by credit and debit, or has his labor and pleasure parcelled out to him by the community,—the law which we have just disengaged will always be fulfilled. Our interest accounts do nothing else than bear witness to it.
2. Values created by net product are classed as savings and capitalized in the most highly exchangeable form, the form which is freest and least susceptible of depreciation,—in a word, the form of specie, the only constituted value. Now, if capital leaves this state of freedom and ENGAGES ITSELF,—that is, takes the form of machines, buildings, etc.,—it will still be susceptible of exchange, but much more exposed than before to the oscillations of supply and demand. Once engaged, it cannot be DISENGAGED without difficulty; and the sole resource of its owner will be exploitation. Exploitation alone is capable of maintaining engaged capital at its nominal value; it may increase it, it may diminish it. Capital thus transformed is as if it had been risked in a maritime enterprise: the interest is the insurance premium paid on the capital. And this premium will be greater or less according to the scarcity or abundance of capital.
Later a distinction will also be established between the insurance premium and interest on capital, and new facts will result from this subdivision: thus the history of humanity is simply a perpetual distinction of the mind's concepts.
3. Not only does interest on capital cause the laborer to enjoy the fruit of his toil and insure his savings, but—and this is the most marvellous effect of interest—while rewarding the producer, it obliges him to labor incessantly and never stop.
If a contractor is his own capitalist, it may happen that he will content himself with a profit equal to the interest on his investment: but in that case it is certain that his industry is no longer making progress and consequently is suffering. This we see when the capitalist is distinct from the contractor: for then, after the interest is paid, the manufacturer's profit is absolutely nothing; his industry becomes a perpetual peril to him, from which it is important that he should free himself as soon as possible. For as society's comfort must develop in an indefinite progression, so the law of the producer is that he should continually realize a surplus: otherwise his existence is precarious, monotonous, fatiguing. The interest due to the capitalist by the producer therefore is like the lash of the planter cracking over the head of the sleeping slave; it is the voice of progress crying: "On, on! Toil, toil!" Man's destiny pushes him to happiness: that is why it denies him rest.
4. Finally, interest on money is the condition of capital's circulation and the chief agent of industrial solidarity. This aspect has been seized by all the economists, and we shall give it special treatment when we come to deal with credit.
I have proved, and better, I imagine, than it has ever been proved before:
That monopoly is necessary, since it is the antagonism of competition;
That it is essential to society, since without it society would never have emerged from the primeval forests and without it would rapidly go backwards;
Finally, that it is the crown of the producer, when, whether by net product or by interest on the capital which he devotes to production, it brings to the monopolist that increase of comfort which his foresight and his efforts deserve.