“The object of this Essay is to assert one very simple principle, as entitled to govern absolutely the dealings of society with the individual in the way of compulsion and control, whether the means used be physical force in the form of legal penalties, or the moral coercion of public opinion. That principle is, that the sole end for which mankind are warranted, individually or collectively in interfering with the liberty of action of any of their number, is self-protection. That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant. He cannot rightfully be compelled to do or forbear because it will be better for him to do so, because it will make him happier, because, in the opinions of others, to do so would be wise, or even right. These are good reasons for remonstrating with him, or reasoning with him, or persuading him, or entreating him, but not for compelling him, or visiting him with any evil, in case he do otherwise. To justify that, the conduct from which it is desired to deter him must be calculated to produce evil to someone else. The only part of the conduct of any one, for which he is amenable to society, is that which concerns others. In the part which merely concerns himself, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.”

“Every individual is continually exerting himself to find out the most advantageous employment for whatever capital he can command. It is his own advantage, indeed, and not that of the society which he has in view. But the study of his own advantage naturally, or rather necessarily, leads him to prefer that employment which is most advantageous to society... He intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was not part of his intention”

“Life is not interested in good and evil. Don Quixote was constantly choosing between good and evil, but then he was choosing in his dream state. He was mad. He entered reality only when he was so busy trying to cope with people that he had no time to distinguish between good and evil. Since people exist only in life, they must devote their time simply to being alive. Life is motion, and motion is concerned with what makes man move—which is ambition, power, pleasure. What time a man can devote to morality, he must take by force from the motion of which he is a part. He is compelled to make choices between good and evil sooner or later, because moral conscience demands that from him in order that he can live with himself tomorrow. His moral conscience is the curse he had to accept from the gods in order to gain from them the right to dream.”

“I can tell by my own reaction to it that this book is harmful." But let him only wait and perhaps one day he will admit to himself that this same book has done him a great service by bringing out the hidden sickness of his heart and making it visible.— Altered opinions do not alter a man’s character (or do so very little); but they do illuminate individual aspects of the constellation of his personality which with a different constellation of opinions had hitherto remained dark and unrecognizable.”

“When an individual is taken into custody or otherwise deprived of his freedom by the authorities and is subjected to questioning . . . he must be warned prior to any questioning that he has the right to remain silent, that anything he says can be used against him in a court of law, that he has the right to the presence of an attorney, and that if he cannot afford an attorney one will be appointed for him prior to any questioning if he so desires.”

“First, individual rights cannot be sacrificed for the sake of the general good, and second, the principles of justice that specify these rights cannot be premised on any particular vision of the good life. What justifies the rights is not that they maximize the general welfare or otherwise promote the good, but rather that they comprise a fair framework within which individuals and groups can choose their own values and ends, consistent with a similar liberty for others.”