If you open the works of any economist you will find that he begins with PRODUCTION, _i. e._, by the analysis of the means employed nowadays for the creation of wealth: division of labour, the factory, its machinery, the accumulation of capital. From Adam Smith to Marx, all have proceeded along these lines. Only in the latter parts of their books do they treat of CONSUMPTION, that is to say, of the means resorted to in our present Society to satisfy the needs of the individuals; and even there they confine themselves to explaining how riches _are_ divided among those who vie with one another for their possession. Perhaps you will say this is logical. Before satisfying needs you must create the wherewithal to satisfy them. But, before producing anything, must you not feel the need of it? Was it not necessity that first drove man to hunt, to raise cattle, to cultivate land, to make implements, and later on to invent machinery? Is it not the study of the needs that should govern production? To say the least, it would therefore be quite as logical to begin by considering the needs, and afterwards to discuss how production is, and ought to be, organized, in order to satisfy these needs. This is precisely what we mean to do. But as soon as we look at Political Economy from this point of view, it entirely changes its aspect. It ceases to be a simple description of facts, and becomes a _science_, and we may define this science as: "_The study of the needs of mankind, and the means of satisfying them with the least possible waste of human energy_". Its true name should be, _Physiology of Society_. It constitutes a parallel science to the physiology of plants and animals, which is the study of the needs of plants and animals, and of the most advantageous ways of satisfying them. In the series of sociological sciences, the economy of human societies takes the place, occupied in the series of biological sciences by the physiology of organic bodies. We say, here are human beings, united in a society. All of them feel the need of living in healthy houses. The savage's hut no longer satisfies them; they require a more or less comfortable solid shelter. The question is, then: whether, taking the present capacity of men for production, every man can have a house of his own? and what is hindering him from having it? And as soon as we ask _this_ question, we see that every family in Europe could perfectly well have a comfortable house, such as are built in England, in Belgium, or in Pullman City, or else an equivalent set of rooms. A certain number of days' work would suffice to build a pretty little airy house, well fitted up and lighted by electricity.