“The most rabidly religious people are the most rabidly evil.”

Ibn Shu’ba al-Harrani, Tuhaf al-'Uqul, p. 519
Religious Wisdom

Desperate Remedies (1871), ch. 1

Source: The Life of the Mind (1978), "Thinking".

Patriotism, or Peace? http://en.wikisource.org/wiki/Patriotism,_or_Peace%3F (1896), translated by Nathan Haskell Dole
Variant:
I have already several times expressed the thought that in our day the feeling of patriotism is an unnatural, irrational, and harmful feeling, and a cause of a great part of the ills from which mankind is suffering, and that, consequently, this feeling – should not be cultivated, as is now being done, but should, on the contrary, be suppressed and eradicated by all means available to rational men. Yet, strange to say – though it is undeniable that the universal armaments and destructive wars which are ruining the peoples result from that one feeling – all my arguments showing the backwardness, anachronism, and harmfulness of patriotism have been met, and are still met, either by silence, by intentional misinterpretation, or by a strange unvarying reply to the effect that only bad patriotism (Jingoism or Chauvinism) is evil, but that real good patriotism is a very elevated moral feeling, to condemn which is not only irrational but wicked.
What this real, good patriotism consists in, we are never told; or, if anything is said about it, instead of explanation we get declamatory, inflated phrases, or, finally, some other conception is substituted for patriotism – something which has nothing in common with the patriotism we all know, and from the results of which we all suffer so severely.
Patriotism and Government http://en.wikisource.org/wiki/Patriotism_and_Government (1900)
Context: Tell people that war is an evil, and they will laugh; for who does not know it? Tell them that patriotism is an evil, and most of them will agree, but with a reservation. "Yes," they will say, "wrong patriotism is an evil; but there is another kind, the kind we hold." But just what this good patriotism is, no one explains.

The American Mercury (March, 1930); first printed, in part, in the Baltimore Evening Sun (9 December 1929)
1920s
Context: The most curious social convention of the great age in which we live is the one to the effect that religious opinions should be respected. Its evil effects must be plain enough to everyone. All it accomplishes is (a) to throw a veil of sanctity about ideas that violate every intellectual decency, and (b) to make every theologian a sort of chartered libertine. No doubt it is mainly to blame for the appalling slowness with which really sound notions make their way in the world. The minute a new one is launched, in whatever field, some imbecile of a theologian is certain to fall upon it, seeking to put it down. The most effective way to defend it, of course, would be to fall upon the theologian, for the only really workable defense, in polemics as in war, is a vigorous offensive. But the convention that I have mentioned frowns upon that device as indecent, and so theologians continue their assault upon sense without much resistance, and the enlightenment is unpleasantly delayed.
There is, in fact, nothing about religious opinions that entitles them to any more respect than other opinions get. On the contrary, they tend to be noticeably silly. If you doubt it, then ask any pious fellow of your acquaintance to put what he believes into the form of an affidavit, and see how it reads…. “I, John Doe, being duly sworn, do say that I believe that, at death, I shall turn into a vertebrate without substance, having neither weight, extent nor mass, but with all the intellectual powers and bodily sensations of an ordinary mammal;... and that, for the high crime and misdemeanor of having kissed my sister-in-law behind the door, with evil intent, I shall be boiled in molten sulphur for one billion calendar years.” Or, “I, Mary Roe, having the fear of Hell before me, do solemnly affirm and declare that I believe it was right, just, lawful and decent for the Lord God Jehovah, seeing certain little children of Beth-el laugh at Elisha’s bald head, to send a she-bear from the wood, and to instruct, incite, induce and command it to tear forty-two of them to pieces.” Or, “I, the Right Rev. _____ _________, Bishop of _________, D. D., LL. D., do honestly, faithfully and on my honor as a man and a priest, declare that I believe that Jonah swallowed the whale,” or vice versa, as the case may be. No, there is nothing notably dignified about religious ideas. They run, rather, to a peculiarly puerile and tedious kind of nonsense. At their best, they are borrowed from metaphysicians, which is to say, from men who devote their lives to proving that twice two is not always or necessarily four. At their worst, they smell of spiritualism and fortune telling. Nor is there any visible virtue in the men who merchant them professionally. Few theologians know anything that is worth knowing, even about theology, and not many of them are honest. One may forgive a Communist or a Single Taxer on the ground that there is something the matter with his ductless glands, and that a Winter in the south of France would relieve him. But the average theologian is a hearty, red-faced, well-fed fellow with no discernible excuse in pathology. He disseminates his blather, not innocently, like a philosopher, but maliciously, like a politician. In a well-organized world he would be on the stone-pile. But in the world as it exists we are asked to listen to him, not only politely, but even reverently, and with our mouths open.

Source: Losing My Virginity: How I've Survived, Had Fun, and Made a Fortune Doing Business My Way

"In Egypt Land," December 30, 1946
TIME magazine (1939-1948)

Source: Against Method (1975), p. 295