minds otherwise capable of receiving it by the transcendental and mystical phraseology in which they were accustomed to shut it up, and from which they neither cared, nor knew how, to disengage it; and I did not despair of separating the truth from the error, and exposing it in terms which would be intelligible and not repulsive to those on my own side in philosophy. Thus prepared, it will easily be believed that when I came into close intellectual communion with a person of the most eminent faculties, whose genius, as it grew and unfolded itself in thought, continually struck out truths far in advance of me, but in which I could not, as I had done in those others, detect any mixture of error, the greatest part of my mental growth consisted in the assimilation of those truths, and the most valuable part of my intellectual work was in building the bridges and clearing the paths which connected them with my general system of thought.[4] The first of my books in which her share was conspicious was the _Principles of Political Economy_. The _System of Logic_ owed little to her except in the minuter matters of composition, in which respect my writings, both great and small, have largely benefited by her accurate and clear-sighted criticism.[5] The chapter of the _Political Economy_ which has had a greater influence on opinion than all the rest, that on 'the Probable Future of the Labouring Classes,' is entirely due to her; in the first draft of the book, that chapter did not exist. She pointed out the need of such a chapter, and the extreme imperfection of the book without it; she was the cause of my writing it; and the more general part of the chapter, the statement and discussion of the two opposite theories respecting the proper condition of the labouring classes, was wholly an exposition of her thoughts, often in words taken from her own lips. The purely scientific part of the _Political Economy_ I did not learn from her; but it was chiefly her influence that gave to the book that general tone by which it is distinguished from all previous expositions of Political Economy that had any pretension to being scientific, and which has made it so useful in conciliating minds which those previous expositions had repelled. This tone consisted chiefly in making the proper distinction between the laws of the Production of Wealth--which are laws of nature, dependent on the properties of objects--and the modes of its Distribution, which, subject to certain conditions, depend on human will. The commom run of political economists confuse these together, under the designation of economic laws, which they deem incapable of being defeated or modified by human effort; ascribing the same necessity to things dependent on the unchangeable conditions of our earthly existence, and to those which, being but the necessary consequences of particular social arrangements, are merely co-extensive with these; given certain institutions and customs, wages,