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. Shall we, then, with the economists, glorify monopoly, and consecrate it to the benefit of well-secured conservatives? I am willing, provided they in turn will admit my claims in what is to follow, as I have admitted theirs in what has preceded. % 2.--The disasters in labor and the perversion of ideas caused by monopoly.