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.
John Stuart MillWhatever helps to shape the human being - to make the individual what he is, or hinder him from being what he is not - is part of his education.
John Stuart MillNext to selfishness the principal cause which makes life unsatisfactory is want of mental cultivation.
John Stuart Mill