This idea of the spontaneous constitution of the economic world is in some aspects analogous to the conception of an “economic law” of a later period. Both ideas suggest the presence of something superior to individual wills, and imposed upon them even despite their resistance. The differences are equally marked, however, the scope of the former being far greater than that of the latter. The words “natural law,” in the first place, suggest regularity and repetition—the constant recurrence of the same phenomena under similar conditions. This is not the aspect that particularly struck Smith. He insists less upon the constancy of economic phenomena and more on their spontaneity, their instinctive and natural character. Say’s delight was to compare the economic and the physical worlds. Smith loves to regard the economic world as a living organism which creates for itself its own indispensable organs. Nowhere is the term “economic law” employed, but his delineation of the chief economic institutions and the account of their functions always results in the same conclusion. First of all take division of labour, which we have just studied, and which more than any other institution contributes to the increase of wealth. This marvellous institution is “not originally the effect of any human wisdom, which foresees and intends that general opulence to which it gives occasion.” “It is the necessary, though very slow and gradual, consequence of a certain propensity in human nature which has in view no such extensive utility; the propensity to truck, barter, and exchange one thing for another.”[160] This tendency itself is the outcome of personal interest. “Man has almost constant occasion for the help of his brethren, and it is in vain for him to expect it from their benevolence only. He will be more likely to prevail if he can interest their self-love in his favour, and show them that it is for their advantage to do for him what he requires of them. Whoever offers to another a bargain of any kind, proposes to do this: Give me that which I want, and you shall have this which you want, is the meaning of every such offer; and it is in this manner that we obtain from one another the far greater part of those good offices which we stand in need of. It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity, but to their self-love, and never talk to them of our own necessities, but of their advantages.”[161] This gives rise to exchange, and with exchange comes division of labour. “And thus the certainty of being able to exchange all that surplus part of the produce of his own labour, which is over and above his own consumption, for such parts of the produce of other men’s labour as he may have occasion for, encourages every man to apply himself to a particular occupation, and