What follows are heavily excerpted sections from ch. III of Mill's On Liberty

CHAPTER III ON INDIVIDUALITY, AS ONE OF THE ELEMENTS OF WELLBEING

 SUCH being the reasons which make it imperative that human beings should be free to form opinions, and to express their opinions without reserve; and such the baneful consequences to the intellectual, and through that to the moral nature of man, unless this liberty is either conceded, or asserted in spite of prohibition; let us next examine whether the same reasons do not require that men should be free to act upon their opinions--to carry these out in their lives, without hindrance, either physical or moral, from their fellow-men, so long as it is at their own risk and peril. This last proviso is of course indispensable. No one pretends that actions should be as free as opinions. On the contrary, even opinions lose their immunity, when the circumstances in which they are expressed are such as to constitute their expression a positive instigation to some mischievous act. An opinion that corndealers are starvers of the poor, or that private property is robbery, ought to be unmolested when simply circulated through the press, but may justly incur punishment when delivered orally to an excited mob assembled before the house of a corn-dealer, or when handed about among the same mob in the form of a placard. Acts of whatever kind, which, without justifiable cause, do harm to others, may be, and in the more important cases absolutely require to be, controlled by the unfavorable sentiments, and, when needful, by the active interference of mankind. The liberty of the individual must be thus far limited; he must not make himself a nuisance to other people. But if he refrains from molesting others in what concerns them, and merely acts according to his own inclination and judgment in things which concern himself, the same reasons which show that opinion should be free, prove also that he should be allowed, without molestation, to carry his opinions into practice at his own cost. That mankind are not infallible; that their truths, for the most part, are only half-truths; that unity of opinion, unless resulting from the fullest and freest comparison of opposite opinions, is not desirable, and diversity not an evil, but a good, until mankind are much more capable than at present of recognizing all sides of the truth, are principles applicable to men's modes of action, not less than to their opinions. As it is useful that while mankind are imperfect there should be different opinions, so is it that there should be different experiments of living; that free scope should be given to varieties of
character, short of injury to others; and that the worth of different modes of life should be proved practically, when any one thinks fit to try them. It is desirable, in short, that in things which do not primarily concern others, individuality should assert itself. Where, not the person's own character, but the traditions of customs of other people are the rule of conduct, there is wanting one of the principal ingredients of human happiness, and quite the chief ingredient of individual and social progress.

In maintaining this principle, the greatest difficulty to be encountered does not lie in the appreciation of means towards an acknowledged end, but in the indifference of persons in general to the end itself. If it were felt that the free development of individuality is one of the leading essentials of well-being; that it is not only a coordinate element with all that is designated by the terms civilization, instruction, education, culture, but is itself a necessary part and condition of all those things; there would be no danger that liberty should be undervalued, and the adjustment of the boundaries between it and social control would present no extraordinary difficulty. But the evil is, that individual spontaneity is hardly recognized by the common modes of thinking as having any intrinsic worth, or deserving any regard on its own account. The majority, being satisfied with the ways of mankind as they now are (for it is they who make them what they are), cannot comprehend why those ways should not be good enough for everybody; and what is more, spontaneity forms no part of the ideal of the majority of moral and social reformers, but is rather looked on with jealousy, as a troublesome and perhaps rebellious obstruction to the general acceptance of what these reformers, in their own judgment, think would be best for mankind.....
 
....On the other hand, itwould be absurd to pretend that people ought to live as if nothing whatever had been known in the world before they came into it; as if experience had as yet done nothing towards showing that one mode of existence, or of conduct, is preferable to another. Nobody denies that people should be so taught and trained in youth, as to know and benefit by the ascertained results of human experience. But it is the privilege and proper condition of a human being, arrived at the maturity of his faculties, to use and interpret experience in his own way. It is for him to find out what part of recorded experience is properly applicable to his own circumstances and character. The traditions and customs of other people are, to a certain extent, evidence of what their experience has taught them; presumptive evidence, and as such, have a claim to this deference: but, in the first place, their experience may be too narrow; or they may not have interpreted it rightly. Secondly, their interpretation of experience may be correct but unsuitable to him. Customs are made for customary circumstances, and customary characters: and his circumstances or his character may be uncustomary. Thirdly, though the customs be both good as customs, and suitable to him, yet to conform to custom, merely as custom, does not educate or develop in him any of the qualities which are the distinctive endowment of a human being. .....
.....He who lets the world, or his own portion of it, choose his plan of life for him, has no need of any other faculty than the ape-like one of imitation. He who chooses his plan for himself, employs all his faculties. He must use observation to see, reasoning and judgment to foresee, activity to gather materials for decision, discrimination to decide, and when he has decided, firmness and self-control to hold to his deliberate decision. And these qualities he requires and exercises exactly in proportion as the part of his conduct which he determines according to his own judgment and feelings is a large one. It is possible that he might be guided in some good path, and kept out of harm's way, without any of these things. But what will be his comparative worth as a human being? It really is of importance, not only what men do, but also what manner of men they are that do it. Among the works of man, which human life is rightly employed in perfecting and beautifying, the first in importance surely is man himself. Supposing it were possible to get houses built, corn grown, battles fought, causes tried, and even churches erected and prayers said, by machinery--by automatons in human form--it would be a considerable loss to exchange for these automatons even the men and women who at present inhabit the more civilized parts of the world, and who assuredly are but starved specimens of what nature can and will produce. Human nature is not a machine to be built after a model, and set to do exactly the work prescribed for it, but a tree, which requires to grow and develop itself on all sides, according to the tendency of the inward forces which make it a living thing.
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Many persons, no doubt, sincerely think that human beings thus cramped and dwarfed, are as their Maker designed them to be; just as many have thought that trees are a much finer thing when clipped into pollards, or cut out into figures of animals, than as nature made them. But if it be any part of religion to believe that man was made by a good Being, it is more consistent with that faith to believe, that this Being gave all human faculties that they might be cultivated and unfolded, not rooted out and consumed, and that he takes delight in every nearer approach made by his creatures to the ideal conception embodied in them, every increase in any of their capabilities of comprehension, of action, or of enjoyment. There is a different type of human excellence from the Calvinistic; a conception of humanity as having its nature bestowed on it for other purposes than merely to be abnegated. "Pagan selfassertion" is one of the elements of human worth, as well as "Christian self-denial."
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Having said that Individuality is the same thing with development, and that it is only the cultivation of individuality which produces, or
can produce, well-developed human beings, I might here close the argument: for what more or better can be said of any condition of human affairs, than that it brings human beings themselves nearer to the best thing they can be? or what worse can be said of any obstruction to good, than that it prevents this? Doubtless, however, these considerations will not suffice to convince those who most need convincing; and it is necessary further to show, that these developed human beings are of some use to the undeveloped--to point out to those who do not desire liberty, and would not avail themselves of it, that they may be in some intelligible manner rewarded for allowing other people to make use of it without hindrance.

In the first place, then, I would suggest that they might possibly learn something from them. It will not be denied by anybody, that originality is a valuable element in human affairs. There is always need of persons not only to discover new truths, and point out when what were once truths are true no longer, but also to commence new practices, and set the example of more enlightened conduct, and better taste and sense in human life. This cannot well be gainsaid by anybody who does not believe that the world has already attained perfection in all its ways and practices. It is true that this benefit is not capable of being rendered by everybody alike: there are but few persons, in comparison with the whole of mankind, whose experiments, if adopted by others, would be likely to be any improvement on established practice. But these few are the salt of the earth; without them, human life would become a stagnant pool. Not only is it they who introduce good things which did not before exist; it is they who keep the life in those which already existed. If there were nothing new to be done, would human intellect cease to be necessary? Would it be a reason why those who do the old things should forget why they are done, and do them like cattle, not like human beings? .....
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....At present individuals are lost in the crowd. In politics it is almost a triviality to say that public opinion now rules the world. The only power deserving the name is that of masses, and of governments while they make themselves the organ of the tendencies and instincts of masses. This is as true in the moral and social relations of private life as in public transactions. Those whose opinions go by the name of public opinion, are not always the same sort of public: in America, they are the whole white population; in England, chiefly the middle class. But they are always a mass, that is to say, collective mediocrity. And what is still greater novelty, the mass do not now take their opinions from dignitaries in Church or State, from ostensible leaders, or from books. Their thinking is done for them by men much like themselves, addressing them or speaking in their name, on the spur of the moment, through the newspapers. I am not complaining of all this. I do not assert that anything better is compatible, as a general rule, with the present low state of the human mind. But that does not hinder the government of mediocrity from being mediocre government. No government by a democracy or a numerous aristocracy, either in its political acts or in the opinions, qualities, and tone of mind which it fosters, ever did or could rise above mediocrity, except in so far as the sovereign Many have let themselves be guided (which in their best times they always have done) by the counsels and influence of a more highly gifted and instructed One or Few. The initiation of all wise or noble things, comes and must come from individuals; generally at first from some one individual. .....
I have said that it is important to give the freest scope possible to uncustomary things, in order that it may in time appear which of these are fit to be converted into customs. But independence of action, and disregard of custom are not solely deserving of encouragement for the chance they afford that better modes of action, and customs more worthy of general adoption, may be struck out; nor is it only persons of decided mental superiority who have a just claim to carry on their lives in their own way. There is no reason that all human existences should be constructed on some one, or some small number of patterns. If a person possesses any tolerable amount of common sense and experience, his own mode of laying out his existence is the best, not because it is the best in itself, but because it is his own mode. Human beings are not like sheep; and even sheep are not undistinguishably alike. A man cannot get a coat or a pair of boots to fit him, unless they are either made to his measure, or he has a whole warehouseful to choose from: and is it easier to fit him with a life than with a coat, or are human beings more like one another in their whole physical and spiritual conformation than in the shape of their feet? If it were only that people have diversities of taste that is reason enough for not attempting to shape them all after one model. But different persons also require different conditions for their spiritual development; and can no more exist healthily in the same moral, than all the variety of plants can in the same physical atmosphere and climate. The same things which are helps to one person towards the cultivation of his higher nature, are hindrances to another. The same mode of life is a healthy excitement to one, keeping all his faculties of action and enjoyment in their best order, while to another it is a distracting burden, which suspends or crushes all internal life. Such are the differences among human beings in their sources of pleasure, their susceptibilities of pain, and the operation on them of different physical and moral agencies, that unless there is a corresponding diversity in their modes of life, they neither obtain their fair share of happiness, nor grow up to the mental, moral, and aesthetic stature of which their nature is capable. Why then should tolerance, as far as the public sentiment is concerned, extend only to tastes and modes of life which extort acquiescence by the multitude of their adherents? Nowhere (except in some monastic institutions) is diversity of taste entirely unrecognized; a person may without blame, either like or dislike rowing, or smoking, or music, or athletic exercises, or chess, or cards, or study, because both those who like each of these things, and those who dislike them, are too numerous to be put down. But the man, and still more the woman, who can be accused either of doing "what nobody does," or of not doing "what everybody does," is the subject of as much depreciatory remark as if he or she had committed some grave moral delinquency. Persons require to possess a title, or some other badge of rank, or the consideration of people of rank, to be able to indulge somewhat in the luxury of doing as they like without detriment to their estimation. To indulge somewhat, I repeat: for whoever allow themselves much of that in dulgence, incur the risk of something worse than disparaging speeches--they are in peril of a commission de lunatico, and of having their property taken from them and given to their relations.

There is one characteristic of the present direction of public opinion, peculiarly calculated to make it intolerant of any marked demonstration of individuality. The general average of mankind are not only moderate in intellect, but also moderate in inclinations: they have no tastes or wishes strong enough to incline them to do anything unusual, and they consequently do not understand those who have,  and class all such with the wild and intemperate whom they are accustomed to look down upon. Now, in addition to this fact which is general, we have only to suppose that a strong movement has set in towards the improvement of morals, and it is evident what we have to expect. In these days such a movement has set in; much has actually been effected in the way of increased regularity of conduct, and discouragement of excesses; and there is a philanthropic spirit abroad, for the exercise of which there is no more inviting field than the moral and prudential improvement of our fellow-creatures. These tendencies of the times cause the public to be more disposed than at most former periods to prescribe general rules of conduct, and endeavor to make every one conform to the approved standard. And that standard, express or tacit, is to desire nothing strongly. Its ideal of character is to be without any marked character; to maim by compression, like a Chinese lady's foot, every part of human nature which stands out prominently, and tends to make the person markedly dissimilar in outline to commonplace humanity.....