To do simply nothing may lead to degeneration instead of increased energy. The possibility of an improved law, which might act as a moral discipline instead of a simply corrupting agency, is simply left out of account; and the tendency to stimulate reckless population is regarded not only as one probable consequence, but as the very essence of all poor-laws. Upon Malthus's assumptions, the statement that sound political and social theories must be based upon systematic inquiry into facts, meant that the individual was the ultimate unalterable unit, whose interest in his own welfare gave the one fulcrum for all possible changes. The ideal 'state of nature' was a fiction. The true basis of our inquiries is the actual man known to us by observation. The main fault of this being was the excess of the instinct of multiplication, and the way to improve him was to show how it might conflict with the instinct of self-preservation. In this shape the doctrine expressed the most characteristic tendency of the Utilitarians, and divided them from the Socialists or believers in abstract rights of man. VI. RENT Here, then, we are at a central point of the Utilitarian creed. The expansive force of population is, in a sense, the great motive power which moulds the whole social structure; or, rather, it forces together the independent units, and welds them into an aggregate. The influence of this doctrine upon other economical speculations is of the highest importance. One critical stage in the process is marked by the enunciation of the theory of rent, which was to become another essential article of the true faith. The introduction of this doctrine is characteristic, and marks the point at which Ricardo superseded Malthus as chief expositor of the doctrine.