his footsteps had necessarily to take into account the great industrial revolution which supervened but a few years after his death. The more immediate result of his teaching and the one which has maintained itself until the present day was the complete overthrow, in this country at least, of the doctrine of protection, and the establishment of free-trade as the basis of orthodox middle-class economics on their practical side.
Thomas Robert Malthus (1756-1834), originally led to speculate on economic questions by the Rousseauite theories of his father, supplied to the classical middle-class economy in his theory of population a new buttress—a buttress which was required against the socialistic aspirations the new conditions were calling forth, more than against the humanitarian sentimentalism of the eighteenth century which was the original occasion of it. The rapid extension of machinery and the consequent displacement of hand labor was driving thousands into the direst poverty and misery, and it behooved economists to find some explanation of this. Malthus thought he had discovered it in his theory that the growth of population always tends to outstrip the food supply, and that hence the cure of poverty lies in the limitation of the numbers of the human race. Since his time this has been accepted as axiomatic by almost all the writers of the classical school of economy, and is generally admitted in one shape or another even by their successors, the "vulgar" economists of today. The "Essay on the Principle of Population," in which his theory was elaborated, was first published in 1798 and expanded into a larger volume in 1803.
David Ricardo (1772-1823) was the first important successor to Adam Smith in the strictly economic field. He
