A fact is a proposition of which the verification by an appeal to the primary sources of our knowledge or to experience is directand simple. A theory, on the other hand, if true, has all the characteristics of a fact except that its verification is possible only by indirect, remote, and difficult means.

We receive the truths of science by compulsion. Nothing but ignorance is able to resist them.

And we owe science to the combined energies of individual men of genius, rather than to any tendency to progress inherent in civilization.

Such evidence is not the only kind which produces belief; though positivism maintains that it is the only kind which ought to produce so high a degree of confidence as all minds have or can be made to have through their agreements.

What a fearful object a long-neglected duty gets to be

Let one persuade many, and he becomes confirmed and convinced, and cares for no better evidence.

The pains of disconcerted or frustrated habits, and the inherent pleasure there is in following them, are motives which nature has put into our wills without generally caring to inform us why; and she sometimes decrees, indeed, that her reasons shall not be ours.