The explanation of this otherwise unaccountable fact is to be found in the general acceptance of the Malthusian theory. The current theory of wages has never been fairly put upon its trial, because, backed by the Malthusian theory, it has seemed in the minds of political economists a self-evident truth. These two theories mutually blend with, strengthen, and defend each other, while they both derive additional support from a principle brought prominently forward in the discussions of the theory of rent—viz., that past a certain point the application of capital and labor to land yields a diminishing return. Together they give such an explanation of the phenomena presented in a highly organized and advancing society as seems to fit all the facts, and which has thus prevented closer investigation. Which of these two theories is entitled to historical precedence it is hard to say. The theory of population was not formulated in such a way as to give it the standing of a scientific dogma until after that had been done for the theory of wages. But they naturally spring up and grow with each other, and were both held in a form more or less crude long prior to any attempt to construct a system of political economy. It is evident, from several passages, that though he never fully developed it, the Malthusian theory was in rudimentary form present in the mind of Adam Smith, and to this, it seems to me, must be largely due the misdirection which on the subject of wages his speculations took. But, however this may be, so closely are the two theories connected, so completely do they complement each other, that Buckle, reviewing the history of the development of political economy in his “Examination of the Scotch Intellect during the Eighteenth Century,” attributes mainly to Malthus the honor of “decisively proving” the current theory of wages by advancing the current theory of the pressure of population upon subsistence. He says in his “History of Civilization in England,” Vol. 3, Chap. 5: “Scarcely had the Eighteenth Century passed away when it was decisively proved that the reward of labor depends solely on two things; namely, the magnitude of that national fund out of which all labor is paid, and the number of laborers among whom the fund is to be divided. This vast step in our knowledge is due, mainly, though not entirely, to Malthus, whose work on population, besides marking an epoch in the history of speculative thought, has already produced considerable practical results, and will probably give rise to others more considerable still. It was published in 1798; so that Adam Smith, who died in 1790, missed what to him would have been the intense pleasure of seeing how, in it, his own views were expanded rather than corrected. Indeed, it is certain that without Smith there would have been no Malthus; that is, unless Smith had laid the foundation, Malthus could not have raised the superstructure.”