Himmelfarb's dense, erudite study of John Stuart Mill, perhaps the most influential and admired of Victorians, has at its core a not so startling thesis: even after he had broken free of his strict Benthamite upbringing, Mill's views were not all of a piece. On Liberty, that famous and resounding essay, was an extreme statement, ""absolutistic and simplistic,"" representing the romantic and elitist libertarianism of Mill's adored wife, Harriet Taylor. The book was the most important fruit of their marriage, ""the philosophical expression of their existential situation."" Mill himself stated emphatically that ""the whole mode of thinking"" was his wife's. The hostility to the conventions and received truths of society, the insistence on unfettered ""individuality"" as the supreme good, on unlimited freedom of action so long as it was not injurious to another person, reflected exactly their personal situation; during the years of his marriage the gregarious and good-natured Mill withdrew entirely from society as he and Harriet lived wholly for each other cultivating in narcissistic, solitary eminence their own high thoughts and feelings. By a rigorous analysis of Mill's earlier and later writings Himmelfarb shows that Mill alone held far more temperate views; the sovereignty of the individual was by no means his chief concern. Mill's interest in representative government, in women's equality and in social cooperation bespoke a realization that in practice the individual is, and must be, restrained by law, tradition and social morality. Himmelfarb prefers this balanced, modulated Whiggish Mill, while acknowledging that the extreme statement of individual rights -- the legacy of his relationship with Harriet Taylor -- has had the greater impact on history, coming to its full flowering in the personal credo of the Bloomsbury set which prized absolute liberty, beauty, and self above all else. The implication of course is that, for all its appeal, the doctrine of On Liberty is socially irresponsible and Himmelfarb's antipathy to Mill's beloved Harriet shows. A somewhat ponderous study of the circumstantial birth of a seminal book.