The _Essay on Population_ was therefore not original in the sense of being a creation out of nothing, but in the same way as the _Wealth of Nations_. In both cases the author got most of his phrases, and even many of his thoughts, from his predecessors; but he treated them as his predecessors were unable to do; he saw them in their connection, perspective, and wide bearings. We must not assume anticipation where there is mere identity of language or partial identity of thought; the words of an earlier writer are not unfrequently quoted by a later away from their logical context, and therefore not as part of an argument of which the writer sees the consecutive premises. This is true of Adam Smith when he is compared with Sir Dudley North, Abraham Tucker, or the other prophets of free trade[57] catalogued by MacCulloch or Blanqui. They talked free trade almost as Mons. Jourdain talked prose, without knowing it. Precisely the same is true of Adam Smith himself in relation to Malthus. Of his own generalizations he is complete master. Having reasoned up to them, he can reason down from them. But, when he says, “Every species of animals naturally multiplies in proportion to the means of their subsistence,” “The demand for men necessarily regulates the production of men,”[58] he has not anticipated Malthus. His phrases are touching a principle of which he does not see the most important bearings; and not having reasoned up to it, he makes hardly any attempt to reason down from it. Malthus, on the other hand, has taken fast hold of a general principle, and is able to solve a number of dependent questions in the way of simple corollaries. Others may have given right answers to the special questions about the Poor Law and the populousness of ancient nations. Malthus is the first to show one comprehensive reason why all these answers must be right. This was the secret of his success. As Godwin’s _Political Justice_ was successful because systematic, the _Essay on Population_ was successful because it seemed to put chaos in order. The very sadness of his conclusion had a charm for some minds; but the bulk of his readers did not love him for taking their hopes away, they loved him for giving them new light. Pestilence and famine begin to lose their vague terrors when we know whence they come and what they do for the world. Even if the desire of marriage is itself an evil, it is well to know the truth about it. Ignorance can only be blissful where it is total; and wilful ignorance, being of necessity partial, is a perpetual unrest, not even a fool’s paradise.[59]