There are two points, especially, of importance here. In the motion of any machine, it is possible to distinguish with the utmost accuracy, between the cause and the effect of the motion: the blowing of the wind, for instance, is simply and purely, the cause of the friction of the mill-stones in a wind-mill, and is not in the least influenced or conditioned by the latter. But, in the public economy of every people, patient thought soon shows the observer, that the most important simultaneous events or phenomena mutually condition one another. Thus, a flourishing state of agriculture is impossible without flourishing industries; but, conversely, the prosperity of the latter supposes the prosperity of the former, as a condition precedent. It is as in the human body. The motions of respiration are produced by the action of the spinal cord; and the spinal cord, in turn, continues to work only through the blood, that is, by the help of respiration. In all cases like this, we are forced, when accounting for phenomena, to move about in a circle, unless we admit the existence of an organic life, of which every individual fact is only the manifestation.(119)(120) It is, also, undeniable, that human insight into the operation and utility of a machine must always precede the existence of the machine itself. This human insight is parent to the plan, and the plan, in turn, is parent to the machine. The very reverse of this is true in the case of organisms, those “divine machines” as Leibnitz called them. Men had digested food and reproduced their kind, thousands of years before physiologists had attained to a true theory of digestion or reproduction. I do not, indeed, by any means, pretend, that the public economy of nations is governed by natural necessity, in the same degree, as for instance, the human body. We shall find, however, that the minute arbitrary variations usual here and there in the course of its development, generally compensate for one another, in accordance with the law of large numbers. Here, too, we find harmonies, frequently of wonderful beauty, which existed long before any one dreamt of them; innumerable _natural laws_,(121) whose operation does not depend on their recognition by individuals, and, over which, only he can obtain power who has learned to obey them. (_Bacon_)(122)(123)(124) But it should never be lost sight of, that the natural laws governing the public economy of a people, like those of the human mind, are distinguished in one very essential point from those of the material world. They have to do with free rational beings, who, because they are thus free and rational, are responsible to God and their conscience, and constitute in their aggregate a species capable of progress. Section XIV. Origin Of A Nation’s Economy.