Before proceeding further in our inquiry, let us make sure of the meaning of our terms, for indistinctness in their use must inevitably produce ambiguity and indeterminateness in reasoning. Not only is it requisite in economic reasoning to give to such words as “wealth,” “capital,” “rent,” “wages,” and the like, a much more definite sense than they bear in common discourse, but, unfortunately, even in political economy there is, as to some of these terms, no certain meaning assigned by common consent, different writers giving to the same term different meanings, and the same writers often using a term in different senses. Nothing can add to the force of what has been said by so many eminent authors as to the importance of clear and precise definitions, save the example (not an infrequent one) of the same authors falling into grave errors from the very cause they warned against. And nothing so shows the importance of language in thought as the spectacle of even acute thinkers basing important conclusions upon the use of the same word in varying senses. I shall endeavor to avoid these dangers. It will be my effort throughout, as any term becomes of importance, to clearly state what I mean by it, and to use it in that sense and in no other. Let me ask the reader to note and to bear in mind the definitions thus given, as otherwise I cannot hope to make myself properly understood.