“The idea that truth always triumphs over persecution is one of those pleasant falsehoods, which most experience refutes. History is teeming with instances of truth put down by persecution. If not put down forever, it may be set back for centuries.”

“The real advantage which truth has, consists in this, that when an opinion is true, it may be extinguished once, twice or many times, but in the course of ages there will generally found person to rediscover it, until some of its reappearances falls on a time when from favourable circumstances it escapes persecution until it has made such head as to withstand all subsequent attempts to suppress it.”

“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.”

“Human beings are no longer born to their place in life, and chained down by an inexorable bond to the place they are born to, but are free to employ their faculties, and such favourable chances as offer, to achieve the lot which may appear to them most desirable.”

“He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion... Nor is it enough that he should hear the opinions of adversaries from his own teachers, presented as they state them, and accompanied by what they offer as refutations. He must be able to hear them from persons who actually believe them...he must know them in their most plausible and persuasive form.”

“It is given to no human being to stereotype a set of truths, and walk safely by their guidance with his mind's eye closed.”

“Such is the facility with which mankind believe at one and the same time things inconsistent with one another, and so few are those who draw from what they receive as truths, any consequences but those recommended to them by their feelings, that multitudes have held the undoubting belief in an Omnipotent Author of Hell, and have nevertheless identified that being with the one best conception they were able to form of perfect goodness.”