This is what I had to say at present upon the co-operation of Nature. Nature places at our disposal, in various degrees, depending on climate, seasons, and the advance of knowledge, but ‹always gratuitously›, materials and forces. Then these materials and forces are devoid of ‹value›; it would be strange if they had any. According to what rule should we estimate them? In what way could Nature be paid, remunerated, compensated? We shall see afterwards that ‹exchange› is necessary in order to determine ‹value›. We don’t purchase the goods of Nature—we gather them; and if, in order to appropriate them, a certain amount of effort is [p092] necessary, it is in this ‹effort›, not in the gifts of Nature, that the principle of ‹value› resides. Let us now consider that action of man which we designate, in a general way, by the term ‹labour›. The word ‹labour›, like almost all the terms of Political Economy, is very vague. Different authors use it in a sense more or less extended. Political Economy has not had, like most other sciences, Chemistry for example, the advantage of constructing her own vocabulary. Treating of subjects which have been familiar to men’s thoughts since the beginning of the world, and the constant subject of their daily talk, she has found a nomenclature ready made, and has been forced to adopt it. The meaning of the word ‹labour› is often limited exclusively to the muscular action of man upon materials. Hence those who execute the mechanical part of production are called the ‹working classes›. The reader will comprehend that I give to this word a more extended sense. I understand by ‹labour› the application of our faculties to the satisfaction of our wants. ‹Wants›, ‹efforts›, ‹satisfactions›, this is the circle of Political Economy. ‹Effort› may be physical, intellectual, or even moral, as we shall immediately see. It is not necessary to demonstrate in this place that all our organs, all or nearly all our faculties, may concur, and, in point of fact, do concur, in production. Attention, sagacity, intelligence, imagination, have assuredly their part in it. M. Dunoyer, in his excellent work, ‹Sur la Liberté du Travail›, has included, and with scientific exactness, our moral faculties among the elements to which we are indebted for our wealth—an idea as original and suggestive as it is just. It is destined to enlarge and ennoble the field of Political Economy. I shall not dwell here upon that idea farther than as it may enable me to throw a faint light upon the origin of a powerful agent of production, of which I shall have occasion to speak hereafter—I mean ‹Capital›.