“We can't have full knowledge all at once. We must start by believing; then afterwards we may be led on to master the evidence for ourselves.”

'La vie n’est facile pour aucun de nous. Mais quoi, il faut avoir de la persévérance, et surtout de la confiance en soi. Il faut croire que l’on est doué pour quelque chose, et que, cette chose, il faut l'atteindre coûte que coûte.'
As quoted in Madame Curie : A Biography (1937) by Eve Curie Labouisse, Part 2, p. 116

The Ethics of Belief (1877), The Duty of Inquiry
Context: A bad action is always bad at the time when it is done, no matter what happens afterwards. Every time we let ourselves believe for unworthy reasons, we weaken our powers of self-control, of doubting, of judicially and fairly weighing evidence. We all suffer severely enough from the maintenance and support of false beliefs and the fatally wrong actions which they lead to, and the evil born when one such belief is entertained is great and wide. But a greater and wider evil arises when the credulous character is maintained and supported, when a habit of believing for unworthy reasons is fostered and made permanent. If I steal money from any person, there may be no harm done from the mere transfer of possession; he may not feel the loss, or it may prevent him from using the money badly. But I cannot help doing this great wrong towards Man, that I make myself dishonest. What hurts society is not that it should lose its property, but that it should become a den of thieves, for then it must cease to be society. This is why we ought not to do evil, that good may come; for at any rate this great evil has come, that we have done evil and are made wicked thereby. In like manner, if I let myself believe anything on insufficient evidence, there may be no great harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous. The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.

The Deception: Lord Jim's Jump (p. 68)
Straw Dogs: Thoughts on Humans and Other Animals (2002)

The Review and Herald (27 March 1890); also in Counsels for Writers and Editors http://books.google.de/books?id=UEM4uBD04asC&printsec=frontcover&dq=Counsels+to+writers+and+editors&cd=1#v=onepage&q&f=false (1946), p. 33; also in Evangelism http://books.google.de/books?id=gsy20ga71LEC&printsec=frontcover&dq=Ellen+Gould+Harmon+White+Evangelism&cd=1#v=onepage&q&f=false (1946), p. 296; also in 1888 - The Ellen G. White 1888 Materials (1987), Ch. 64, p. 547.

2010s
Source: Jonah Lehredec. " A Physicist Solves the City http://www.nytimes.com/2010/12/19/magazine/19Urban_West-t.html?pagewanted=5&_r=1," in www.nytimes.com. Dec 17, 2010.

Source: Faith of the Fallen

22
Sovereign Maxims

Source: Aphorisms and Reflections (1901), p. 238

Literary Remains