There is the greatest difference between presuming an opinion to be true, because, with every opportunity for contesting it, it has not been refuted, and assuming its truth for the purpose of not permitting its refutation.

Whether moral and social phenomena are really exceptions to the general certainty and uniformity of the course of nature; and how far the methods, by which so many of the laws of the physical world have been numbered among truths irrevocably acquired and universally assented to, can be made instrumental to the gradual formation of a similar body of received doctrine in moral and political science.

The demand for commodities is not the demand for labor.

However unwillingly a person who has a strong opinion may admit the possibility that his opinion may be false, he ought to be moved by the consideration that, however true it may be, if it is not fully, frequently, and fearlessly discussed, it will be held as a dead dogma, not a living truth.

Complete liberty of contradicting and disproving our opinion, is the very condition which justifies us in assuming its truth for purposes of action.

The object of universities is not to make skillful lawyers, physicians or engineers. It is to make capable and cultivated human beings

Men might as well be imprisoned, as excluded from the means of earning their bread.