“In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence..”

Source: Faith vs. Fact (2015), p. 171

Section 10 : Of Miracles Pt. 1
An Enquiry Concerning Human Understanding (1748)

AV Club interview http://www.avclub.com/article/stephen-colbert-13970, (25 January 2006)
Context: Truthiness is tearing apart our country, and I don't mean the argument over who came up with the word. I don't know whether it's a new thing, but it's certainly a current thing, in that it doesn't seem to matter what facts are. It used to be, everyone was entitled to their own opinion, but not their own facts. But that's not the case anymore. Facts matter not at all. Perception is everything. It's certainty. People love the president because he's certain of his choices as a leader, even if the facts that back him up don't seem to exist. It's the fact that he's certain that is very appealing to a certain section of the country. I really feel a dichotomy in the American populace. What is important? What you want to be true, or what is true?

Anarchism: Its Philosophy and Ideal (1896)
Context: A different conception of society, very different from that which now prevails, is in process of formation. Under the name of Anarchy, a new interpretation of the past and present life of society arises, giving at the same time a forecast as regards its future, both conceived in the same spirit as the above-mentioned interpretation in natural sciences. Anarchy, therefore, appears as a constituent part of the new philosophy, and that is why Anarchists come in contact, on so many points, with the greatest thinkers and poets of the present day.
In fact, it is certain that in proportion as the human mind frees itself from ideas inculcated by minorities of priests, military chiefs and judges, all striving to establish their domination, and of scientists paid to perpetuate it, a conception of society arises, in which conception there is no longer room for those dominating minorities. A society entering into possession of the social capital accumulated by the labor of preceding generations, organizing itself so as to make use of this capital in the interests of all, and constituting itself without reconstituting the power of the ruling minorities. It comprises in its midst an infinite variety of capacities, temperaments and individual energies: it excludes none. It even calls for struggles and contentions; because we know that periods of contests, so long as they were freely fought out, without the weight of constituted authority being thrown on the one side of the balance, were periods when human genius took its mightiest flight and achieved the greatest aims. Acknowledging, as a fact, the equal rights of all its members to the treasures accumulated in the past, it no longer recognizes a division between exploited and exploiters, governed and governors, dominated and dominators, and it seeks to establish a certain harmonious compatibility in its midst — not by subjecting all its members to an authority that is fictitiously supposed to represent society, not by trying to establish uniformity, but by urging all men to develop free initiative, free action, free association.
It seeks the most complete development of individuality combined with the highest development of voluntary association in all its aspects, in all possible degrees, for all imaginable aims; ever changing, ever modified associations which carry in themselves the elements of their durability and constantly assume new forms, which answer best to the multiple aspirations of all.

The Life of Edward Jenner M.D. Vol. 2 (1838) by John Baron, p. 447

"The Absurd" in Mortal Questions, Cambridge University Press, 1979, p. 23.

Source: 1860s, Evidence as to Man's Place in Nature (1863), Ch.2, p. 95

Fichte Studies § 556

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 491.