The first and last paragraphs below describe the Oxford World's Classics edition; the rest refer generally to Mill's On Liberty, Utilitarianism, Considerations on Representative Government, and The Subjection of Women.
This collects four of John Stuart Mill's best-known and most influential essays. The main topics are different, but the essays are tightly connected - not only written close together but fitting to a greater or lesser extent the ambitious philosophical system outlined in Mill's A System of Logic. His life project was essentially to adapt the utilitarian moral/political philosophy inherited from Jeremy Bentham via his father James Mill to mid-Victorian social problems. This involved significant changes and substantial liberalizing, making Mill a classical liberalism exponent and strong forerunner of all subsequent liberal ideals and practices. Together and individually, the essays have had an immense impact on political, moral, philosophical, and economic thought. Reading them together is instructive and interesting. Most editions with the first three essays do not have The Subjection, giving this added value. The writings are also held together by Mill's consistently lucid, smooth, and articulate style. This is a pleasant surprise given his fearsomely learned reputation. He relies almost exclusively on words the average reader understands, and his prose is remarkably readable a century and a half later, lacking the overblown floweriness and excessive stiltedness that now make much Victorian writing, especially non-fiction, insufferably dull.
On Liberty is a profound and engaging philosophical and practical defense of personal liberty, epitomized by the famous Harm Principle that all are free to do as they wish provided it does not harm others. It is the state's job to ensure the former right is upheld and the latter transgression punished. Mill's argument is very strong - convincing not only as an inherent right but also as a practical advantage to individuals and society. This is probably now his most famous work, and it is very easy to see why; his argument is not only compelling philosophically but widely applicable and, at about 140 pages, easily read by nearly all. Everyone from pure philosophers to political theorists to practical politicians to general readers can find something to like and learn.
Utilitarianism is Mill's most direct attempt to refine his inherited doctrine. Even more concise than On Liberty, this also essentially picks up where it left off, delving into the practical problem of how to deal with conflicting liberties. Mill retains the core utilitarian tenet that what brings the most happiness for the most people should be acted on - a very appealing doctrine in itself and put forth more palatably and persuasively than by the prior generation. However, utilitarianism's many critics will find little to convince them; however ideally attractive, many practical problems arise when issues such as relative happiness and harm turn up, as well as the thorny problem of how to enforce utilitarianism and punish transgressions. Mill makes some headway, covering nearly all conceivable ground in general principles but leaving much practical application unaddressed. It may be the most spirited utilitarianism defense ever but unfortunately is not complete, however admirable in many ways.
Considerations takes up about half the collection and is more dated than the essentially timeless prior two works but still very interesting and even useful. It in many ways follows directly from Utilitarianism, as it is in essence a practical application of utilitarian principles to modern government, thus potentially at least partly satisfying some who were put off by the prior essay's gaps. A systematic and near-comprehensive look at representative government, especially the British Victorian variety, it is a nice overview of an extremely relevant subject and interesting both historically and practically. Anyone wanting to know how representative government then stood need look no further, as Mill is extraordinarily candid, especially for someone who was actually a Member of Parliament, on both its pros and cons. His enumeration of the former may sometimes strikes present-day readers as at least slightly wrong-headed - though surprisingly rarely, given the many changes since made. He is even more eloquent speaking of the latter and offers numerous cogent reforms. Many of the problems - e.g., lack of female suffrage - have of course since been corrected; reading about these is a reassuring sign that governmental progress has been made despite all. That said, it can come as a great disappointment that several of the problems, such as minority disenfranchisement, are still very much with us; perhaps incredibly, others, such as representatives' inadequate morality/intelligence level, have even worsened. Some of Mill's proposals - for instance, having a non-partisan expert committee draft bills rather than the legislature - are at least as appealing now. That a century and a half has passed without their enactment is frustrating and even appalling.
However historically valuable, the years have inevitably dated this essay somewhat, diluting its value. Aside from the obvious fact that some - though surprisingly little - of it is now moot, a few of Mill's Victorian assumptions, including Eurocentrism, as well as his general hostility to welfare, will certainly make current liberals shudder. That even one of the era's most outspoken and outstanding liberals could hold such views may disappoint but can also be seen as a sign of how far liberalism has come - or even as evidence of the historical march toward progress in which Mill so fervently believed. His European, and specifically British, focus may also lessen the value, but most of what he says is universally valuable.
The Subjection deals exclusively with a subject at least implied in the three prior essays and dealt with explicitly but briefly dealt in Considerations - female oppression. This classic essay is the culmination of an issue Mill had been passionately involved in since youth, when he was arrested for distributing literature about contraception. It is the most important, famous, and influential feminist text between Mary Wollstonecraft's Vindication of the Rights of Woman and Betty Friedan's The Feminine Mystique, coming about halfway between them. That it was written by a man, one born to a substantial amount of privilege and who was around very few women until adulthood at that, is of course all the more incredible. Going well beyond Considerations' suffrage call, it pushes for nothing less than full equality, not even stopping at legal equality but valiantly trying to change thought and custom. Mill's suffrage arguments are numerous and near-irrefutable. He has the noble distinction of being the first MP to propose female suffrage - in the 1860s! He would surely be glad to know the substantial progress since made, however disappointed - if not surprised - he may have been to know it would take sixty years to be realized.
However, the vast majority of the essay deals with the rest of female oppression, a far more formidable barrier - one that, indeed, has sadly still not been fully crossed. The arguments are again very strong. Following a short historical overview of female oppression and a blunt survey of its then current forms, Mill proceeds to demolish its basis. In perhaps the most brilliant and admirable application of utilitarianism ever, he convincingly shows that female oppression is not only a great evil to women but also to men and all of society. He uses many examples and arguments to show that ending it is both a moral necessity and a prescription for many social ills. The many later advances have proven much of what he said, even if he was perhaps too optimistic in some respects. It is a sad comment on human progress that several of the ideals he passionately and articulately argued for, such as equality of intellect in marriage, are still uncommon and even scorned.
Though Subjection is admitted even by Mill's many detractors to be his argumentative tour de force, it has a few limitations. First, as John Gray's Introduction points out, one of his main arguments is that Victorian - nay, all historical - assumptions about inherent differences between men and women, as well as the latter's inferiority, are premature because women had never existed in a state of social equality with men. This is certainly true as far as it goes - indeed, irrefutable at the time. Though he argues forcefully for equality in any situation, he does not even address the substantial question of what, if anything, should or must be done if inherent differences are found. This defect was then nothing more than abstract and, in fact, very subservient to the cause of advancing female rights. However, the near-equality women now have in developed countries means we must look at the issue somewhat differently. The question of inherent differences, much less relative superiority, is still far from answered - may indeed be even less clear. Even so, many of the issues Mill left unaddressed because moot are now very real, even pressing. They may leave his central arguments untouched - one would in fact be very hard-pressed to find a better argument for female equality anywhere -, but the essay is certainly more incomplete now, though still substantially valuable. Finally, though Mill's liberalism on the question is almost unbelievable for a man of his time and place, some of his statements and suggestions, not least his claim that the arrangement of man as breadwinner/woman as domestic engineer - to use the (I believe) currently politically correct term - probably is best after all, will rankle current feminists. To be fair, he does not say it prescriptively - indeed refrains from ruling anything out for women in any respect -, but Victorianism's ugly specter sneaking in even here is bound to disturb some. This of course hardly negates the rest, and The Subjection is still - and surely always will be - essential for anyone even remotely interested in women's struggle.
Anyone curious about Mill or any of these issues needs to read these essays. As for this edition, it may not be the best. The inclusiveness is valuable, but it is very poorly edited. I have read hundreds, perhaps thousands, of books, and this has by far the worst Introduction I have seen. Whether from political considerations, sheer perversity, or whatever else, it is really nothing more than a fairly thorough and very negative refutation of Mill's ideas. He is certainly not infallible, and critiques are welcomed, but the lopsidedness is bizarre. I suggest skipping it, but those who just cannot resist should read it as an Afterword; seeing it first makes it hard to read Mill with an open mind. Even those who agree with him and/or disagree with Gray will inevitably have a hard time reading without assumptions after the Introduction's outrageous bias, while those who agree with Gray have no reason to even read Mill. Thankfully, most will probably not get through Gray, as he makes his Introduction unnecessarily hard to read by using a plethora of technical terms only those intimate with philosophy will understand - the very thing Mill avoids. Gray also does not have nearly enough notes. Mill makes many historical and contemporary references, including numerous ones very briefly, that current readers cannot be expected to know. For example, he refers to "the most eminent woman" of the time making a call for female suffrage. His readers surely knew her, but those today hardly automatically will. Sadly, Gray rarely gives any help; at one point he does not even translate Greek! Conversely and equally frustratingly, he for some reason feels the need to annotate obvious references to the likes of Gulliver's Travels and Uncle Tom's Cabin. Finally, The Subjection has a shocking number of obvious typos - more than I have ever seen in a classic text from a major publisher. The Oxford World's Classics series is usually very good about such things and even usually has, if anything, too many endnotes, making Gray's dearth all the more perplexing. Those wanting a large representative dose of Mill would thus do very well to get this book, but Gray is so irksome that Oxford should not be surprised if readers opt for another edition - or wish they had.