But I think the necessity is only in seeming. If the proposition be analyzed it will be seen to belong to a class that depend for validity upon an implied or suggested qualification—a truth relatively, which taken absolutely becomes a non-truth. For that man cannot exhaust or lessen the powers of nature follows from the indestructibility of matter and the persistence of force. Production and consumption are only relative terms. Speaking absolutely, man neither produces nor consumes. The whole human race, were they to labor to infinity, could not make this rolling sphere one atom heavier or one atom lighter, could not add to or diminish by one iota the sum of the forces whose everlasting circling produces all motion and sustains all life. As the water that we take from the ocean must again return to the ocean, so the food we take from the reservoirs of nature is, from the moment we take it, on its way back to those reservoirs. What we draw from a limited extent of land may temporarily reduce the productiveness of that land, because the return may be to other land, or may be divided between that land and other land, or, perhaps, all land; but this possibility lessens with increasing area, and ceases when the whole globe is considered. That the earth could maintain a thousand billions of people as easily as a thousand millions is a necessary deduction from the manifest truths that, at least so far as our agency is concerned, matter is eternal and force must forever continue to act. Life does not use up the forces that maintain life. We come into the material universe bringing nothing; we take nothing away when we depart. The human being, physically considered, is but a transient form of matter, a changing mode of motion. The matter remains and the force persists. Nothing is lessened, nothing is weakened. And from this it follows that the limit to the population of the globe can be only the limit of space. Now this limitation of space—this danger that the human race may increase beyond the possibility of finding elbow room—is so far off as to have for us no more practical interest than the recurrence of the glacial period or the final extinguishment of the sun. Yet remote and shadowy as it is, it is this possibility which gives to the Malthusian theory its apparently self-evident character. But if we follow it, even this shadow will disappear. It, also, springs from a false analogy. That vegetable and animal life tend to press against the limits of space does not prove the same tendency in human life.