The deepest sin against the human mind is to believe things without evidence.
attributed to, as quoted by Haught, 2000 Years of Disbelief, p. 148
But the faithful who fly to allegory in order to escape absurdity resemble nothing so much as the sheep in the fable who — to save their lives — jumped into the pit. The allegory pit is too commodious, is ready to swallow up so much more than one wants to put in it.
Agnosticism and Christianity, p. 324
It may be quite true that some negroes are better than some white men; but no rational man, cognizant of the facts, believes that the average negro is the equal, still less the superior, of the white man. And if this be true, it is simply incredible that, when all his disabilities are removed, and our prognathous relative has a fair field and no favor, as well as no oppressor, he will be able to compete successfully with his bigger-brained and smaller-jawed rival, in a contest which is to be carried on by thoughts and not by bites. The highest places in the hierarchy of civilization will assuredly not be within the reach of our dusky cousins, though it is by no means necessary that they should be restricted to the lowest.
”Emancipation—Black and White” (1865) in Lay Sermons, Addresses and Reviews