But neither the reasoning of Mr. Mill, nor the example of Mr. Ricardo, induce me to treat Political Economy as an hypothetical science. I do not think it necessary, and, if unnecessary, I do not think it desirable. It appears to me, that if we substitute for Mr. Mill’s hypothesis, that wealth and costly enjoyment are the _only_ objects of human desire, the statement that they are universal and constant objects of desire, that they are desired by all men and at all times, we shall have laid an equally firm foundation for our subsequent reasonings, and have put a truth in the place of an arbitrary assumption. We shall not, it is true, from the fact that by acting in a particular manner a labourer may obtain higher wages, a capitalist larger profits, or a landlord higher rent, be able to infer the further fact that they will certainly act in that manner, but we shall be able to infer that they will do so in the absence of disturbing causes. And if we are able, as will frequently be the case, to state the cases in which these causes may be expected to exist, and the force with which they are likely to operate, we shall have removed all objection to the positive as opposed to the hypothetical treatment of the science. I have said that the hypothetical treatment of the science, if unnecessary, is undesirable. It appears to me to be open to three great objections. In the first place it is obviously unattractive. No one listens to an exposition of what might be the state of things under given but unreal conditions, with the interest with which he hears a statement of what is actually taking place. In the second place, a writer who starts from arbitrarily assumed premises, is in danger of forgetting, from time to time, their unsubstantial foundation, and of arguing as if they were true. This has been the source of much error in Ricardo. He assumed the land of every country to be of different degrees of fertility, and rent to be the value of the difference between the fertility of the best and of the worst land in cultivation. The remainder of the produce he divided into profit and wages. He assumed that wages naturally amount to neither more nor less than the amount of commodities which nature or habit has rendered necessary to maintain the labourer and his family in health and strength. He assumed that, in the progress of population and wealth, worse and worse soils are constantly resorted to, and that agricultural labour, therefore, becomes less and less proportionately productive; and he inferred that the share of the produce of land taken by the landlord and by the labourer must constantly increase, and the share taken by the capitalist constantly diminish.