the premises of Political Economy are those which influence the production and distribution of wealth; and in order that the science should be absolutely perfect, so that an economist might predict the course of economic phenomena with the same accuracy and certainty with which an astronomer predicts the course of celestial phenomena, it would be necessary that these premises should include every fact, mental and physical, which influences the phenomena of wealth.

It does not, however, seem possible that this degree of perfection should ever be attained. In Political Economy, as in all those branches of inquiry which include amongst their premises at once the moral and physical nature of man, the facts to be taken account of are so numerous, their character so various, and the laws of their sequence so obscure, that it would seem scarcely possible to ascertain them all, much less to assign to each its exact value. And even if this were possible, the task of tracing these princiciples to their consequences, allowing to each its due significance, and no more than its due significance. would present a problem so complex and difficult as probably to defy the powers of the most accomplished

reasoners.

But although this is so, and although, therefore, neither Political Economy, nor any of the class of inquiries to which it belongs, may ever be expected to reach that perfection which has been attained in some of the more advanced physical sciences, yet this does

not forbid us to hope that, by following in our economic investigations the same course which has been pursued with such success in physical science, we may attain, if not to absolute scientific perfection, at least to the discovery of solid and valuable results.

The desires, passions, and propensities which influence mankind in the pursuit of wealth are, as I have intimated, almost infinite; yet amongst these there are some principles of so marked and paramount a character as both to admit of being ascertained, and, when ascertained, to afford the data for determining the most important laws of the production and distribution of wealth, in so far as these laws are affected by mental causes. To possess himself of these is the first business of the political economist: he has then to take account of some leading physiological facts connected with human nature; and lastly to ascertain the principal physical characteristics of those natural agents of production on which human industry is exercised. Thus he will consider, as being included amongst the paramount mental principles to which I have alluded, the general desire for wealth, the aversion to labour, the consequent desire to obtain wealth at the least possible sacrifice, the intellectual power of judging of the efficacy of means to an end; he will further duly weigh those propensities which, in conjunction with the physiological conditions of the human frame, determine the laws of population; and, lastly, he will take into account the physical qualities of the soil and of those other natural agents on which the

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labour and ingenuity of man are employed. These facts, whether mental or physical, he will consider, as I have already stated, not with a view to explain them, but as the data of his reasoning, as leading causes affecting the production and distribution of wealth.

But it must not be thought that, when these cardinal facts have been ascertained and their consequences duly developed, the labours of the political economist are at an end, even supposing that his treatment of them has been exhaustive and his reasoning without a flaw. Though the conclusions thus arived at will, in the main, correspond with the actual course of events, yet great and glaring discrepancies will frequently occur. The data on which his speculations have been based include indeed the grand and leading causes which regulate the production and distribution of wealth, but they do not include all the causes. Many subordinate influences (subordinate, I mean, in relation to the purposes of Political Economy) will intervene to disturb, and occasionally to reverse the operation of the more powerful principles, and thus to modify the resulting phenomena. The next step, therefore, in his investigations, will be to endeavour as far as possible to ascertain the character of those subordinate causes, whether physical or mental, which influence human conduct in the pursuit of wealth, and these, when he has found them and is enabled to appreciate them with sufficient accuracy, he will incorporate amongst the axioms of the science, as data to be taken account of in his future speculations.

Thus any great discovery in the arts of production, such, e. g. as the steam-engine, will be a new fact for the consideration of the political economist; it will be for him to consider its effect on the productiveness of industry or the distribution of its products; how far and in what directions it is calculated to affect wages, profits, and rent, and to modify those conclusions to which he may have been led by reasoning from the state of productive industry previous to its introduction. It will be like the discovery to an astronomer of a new planet, the attraction of which, operating on all the heavenly bodies within the sphere of its influence, will cause them more or less to deviate from the path which had been previously calculated for them. It is a new force, which, in speculating on the tendencies of economic phenomena, the political economist will include as a new datum amongst his premises.

In the same way, also, those motives and principles of action which may be developed in the progress of society-so far as they may be found to affect the phenomena of wealth-will also be taken account of by the political economist. He will consider, e. g. the influence of custom in modifying human conduct in the pursuit of wealth; he will consider how, as civilization advances, the estimation of the future in relation to the present is enhanced, and the desire for immediate enjoyment is controlled by the increasing efficacy of prudential restraint; he will also observe how ideas of decency, comfort, and luxury are developed as society progresses, modifying the natural

force of the principles of population, influencing the mode of expenditure of different classes, and affecting thereby the distribution of industrial products.

As I have already remarked, it is scarcely possible that all these circumstances should be ascertained, or accurately appreciated; but it seems quite possible that some of the most important of them may, with sufficient accuracy at least to be made available as data for subsequent deductions, and be entitled to a place among the premises of the science. And in proportion as this is done, in proportion to the completeness of its premises and to the skill with which they are reasoned upon, will the science of Political Economy approximate towards that perfection which has been attained in other branches of knowledge; in the same degree will its conclusions correspond with actual events, and its doctrines become safe and reliable guides to the practical statesman and the philanthropist. Having now considered the character and limits of Political Economy, I shall conclude this lecture by adverting briefly to a point-not, as might at first sight seem, of purely theoretic importance, on which some high authorities are at variance. I allude to the question whether Political Economy be a positive or a hypothetical science. To her

It does not appear that the meaning of the terms "positive" and "hypothetical," as they have been used in this controversy, has been precisely fixed, and I am disposed to think that the difference of opinion which prevails may, in a great measure, be resolved into