About the time of his entering the India House Mill read Du mont's exposition of Bentham's doctrines in the Traite de Legis lation, which made a lasting impression upon him. When he laid down the last volume, he says, he had become a different being. It gave unity to the detached and fragmentary parts of his knowledge and beliefs. The impression was confirmed by the study of the English psychologists, also of Condillac and Helvetius, and in 1822-23 he established among a few friends the "Utilitarian" Society, taking the word, as he tells us, from Galt's Annals of the Parish. Two newspapers were open to him—the Traveller, edited by a friend of Bentham's, and the Morning Chronicle, edited by his father's friend Black. One of his first efforts was a solid argument for freedom of discussion, in a series of letters to the Chronicle on the prosecution of Richard Carlile. He seized every chance for exposing departures from sound principle in parliament and courts of justice. Another outlet was opened up for him (April 1824) by the starting of the Westminster Review, which was the organ of the philosophic radicals. In 1825, too, he edited Bentham's Rationale of Judicial Evidence. He discussed eagerly with the many men of distinction who came to his father's house, and engaged in set discussions at a reading society formed at Grote's house in 1825, and in set debates at a Speculative Society formed in the same year.
The Autobiography tells how in 1826 Mill's enthusiasm was checked by a misgiving as to the value of the ends which he had set before him. At the Speculative Debating Society, where he first measured his strength in public conflict, he found himself looked upon with curiosity as a precocious phenomenon, a "made man," an intellectual machine set to grind certain tunes. He now saw that regard for the public good was too vague an object for the satisfac tion of a man's affections. It is a proof of the dominating force of his father's character that it cost the younger Mill such an effort to shake off his stern creed about poetry and personal emotion. Like Plato, the elder Mill would have put poets under ban as enemies of truth, and he subordinated private to public affections, Landor's maxims of "few acquaintances, fewer friends, no famil iarities" had his cordial approval. These doctrines the younger Mill now felt himself forced in reason to abandon. Too much in awe of his father to make him a confidant, he wrestled in gloomy solitude. He emerged from the struggle with a more catholic view of human happiness, a delight in poetry for its own sake, a more placable attitude in controversy, a hatred of sectarianism, an ambi tion, no less noble and disinterested, but moderated to practical possibilities. Gradually the debates in the Speculative Society attracted men whose society was invigorating and inspiring, among others Maurice and John Sterling. He ceased to attend the society in 1829, but he carried away from it the conviction that a true system of political philosophy was "something much more com plex and many-sided than he had previously had any idea of, and that its office was to supply, not a set of model institutions but principles from which the institutions suitable to any given cir cumstances might be deduced."
His letters in the Examiner in the autumn of 183o after a visit to Paris, where he made the acquaintance of the younger liberals, may be taken as marking his return to hopeful aspiring activity. His enthusiasm for humanity had been thoroughly reawakened, and had taken shape as an aspiration to supply an unimpeachable method of search for conclusions in moral and social science. But he could not at once shake off his early training. He had been bred by his father in a great veneration for the syllogistic logic as an antidote against confused thinking. He attributed to his early discipline in this logic an impatience of vague language which in all likelihood was really fostered in him by his study of the Platonic dialogues and of Bentham, for he always had in himself more of Plato's fertile ingenuity in canvassing the meaning of vague terms than the schoolman's rigid consistency in the use of them. But he was determined that the new logic should stand in no antagonism to the old. In his Westminster review of Whately's Logic in 1828 he defended the syllogistic logic against highfliers such as the Scottish philosophers who talk of "superseding" it by "a supposed system of inductive logic." His inductive logic must "supplement and not supersede." But for several years he searched in vain for the means of concatenation.
Meantime, he had ceased (1828) to write for the Westminster, but during the years 1832 and 1833 he contributed many essays to Tait's Magazine, the Jurist, and the Monthly Repository. In 1835 Sir William Molesworth founded the London Review with Mill as editor; it was amalgamated with the Westminster (as the London and Westminster Review) in 1836, and Mill continued editor (latterly proprietor also) till 1840. Some of his essays writ ten for these journals were reprinted in his first two volumes of Dissertations and Discussions (1859). The essays on Bentham and Coleridge constituted the first manifesto of the new spirit which Mill sought to breathe into English Radicalism. In 1837, on reading Whewell's Inductive Sciences and re-reading Herschel, Mill at last saw his way clear both to formulating the methods of scientific investigation and joining on the new logic as a supple ment to the old. The Logic was published in 1843. In 1844 ap peared his Essays on Some Unsettled Questions in Political Econ omy. Four out of the five are solutions of perplexing technical problems—the distribution of the gains of international com merce, the influence of consumption on production, the definition of productive and unproductive labour, the precise relations be tween profits and wages. Though Mill appears here purely as the disciple of Ricardo, striving after more precise statement, and reaching forward to further consequences, he appears as an original and independent thinker.