On the Character and Definition of Political Economy regarded as a Positive Science

Political economy, regarded as a positive science, is often briefly defined as the science of the phenomena of wealth; and this definition has the merit of directness and simplicity. In as much as the production of material wealth is dependent largely upon physical conditions, it may be asked whether political economy does not partake to some extent of the nature of physical science. It pre-supposes psychology just as it presupposes the physical sciences, and the natural starting point for the economist in his more abstract enquiries is a consideration of the motives by which individuals are usually influenced in their economic relations; but the science is not therefore a branch of psychology. Wealth may then be defined as consisting of all potentially exchangeable means of satisfying human needs. Economic activity is defined as human activity which directs itself towards the production and appropriation of such means of satisfying human needs as are capable of being made the subject of exchange.