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.

The accidental causes of science are only accidents relatively to the intelligence of a man.

The very hope of experimental philosophy, its expectation of constructing the sciences into a true philosophy of nature, is basedon induction, or, if you please, the a priori presumption, that physical causation is universal; that the constitution of nature is written in its actual manifestations, and needs only to be deciphered by experimental and inductive research; that it is not a latent invisible writing, to be brought out by the magic of mental anticipation or metaphysical mediation.

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.

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.

The questions of philosophy proper are human desires and fears and aspirations - human emotions - taking an intellectual form.

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.