I believe in spectacles, but I think eyes necessary too. - John Stuart Mill

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.

No longer enslaved or made dependent by force of law, the great majority are so by force of poverty; they are still chained to a place, to an occupation, and to conformity with the will of an employer, and debarred, by the accident of birth both from the enjoyments, and from the mental and moral advantages, which others inherit without exertion and independently of desert. That this is an evil equal to almost any of those against which mankind have hitherto struggled, the poor are not wrong in believing. Is it a necessary evil? They are told so by, those who do not feel it — -by those who have gained the prizes in the lottery of life. But it was also said that slavery, that despotism, that all the privileges of oligarchy, were necessary.

Language is evidently one of the principle instruments or helps of thought; and any imperfection in the instrument, or in the mode of employing it, is confessedly liable, still more than in almost any other art, to confuse and impede the process, and destroy all ground of confidence in the result.