We at Heterodox Academy are big fans of John Stuart Mill, an English philosopher, political economist and civil servant who wrote one of the most important works in the liberal tradition: On Liberty. If you have spent time on our site or social media channels, you have seen us refer to his brilliance and foresight on the need for viewpoint diversity in order to find truth, and on the value of hearing other perspectives. On the occasion of what would be his 211th birthday, we honor J.S. Mill by including some of his most famous— and currently relevant— quotes below.

“the only way in which a human being can make some approach to knowing the whole of a subject, is by hearing what can be said about it by persons of every variety of opinion, and studying all modes in which it can be looked at by every character of mind. No wise man ever acquired his wisdom in any mode but this; nor is it in the nature of human intellect to become wise in any other manner.”


“He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion… Nor is it enough that he should hear the opinions of adversaries from his own teachers, presented as they state them, and accompanied by what they offer as refutations. He must be able to hear them from persons who actually believe them…he must know them in their most plausible and persuasive form.”


“In all intellectual debates, both sides tend to be correct in what they affirm, and wrong in what they deny.”

Do you have any favorite quotes by J.S. Mill or favorite passages from On Liberty? Let us know in the comments.