"The world holds two classes of men -- intelligent men
without religion, and religious men without intelligence."
[Abu'l-Ala-Al-Ma'arri (973-1057; Syrian poet)]

If forgers and malefactors are put to death by the secular power, there is much more reason for excommunicating and even putting to death one convicted of heresy."
Thomas Aquinas (1225-1274), Summa Theologica

Humanity has the stars in its future, and that future is too important to be lost under the burden of juvenile folly and ignorant superstition.
Isaac Asimov

Often a non-Christian knows something about the earth, the heavens, and the other parts of the world, about the motions and orbits of the stars and even their sizes and distances,...  and this knowledge he holds with certainty from reason and experience.  It is thus offensive and disgraceful for an unbeliever to hear a Christian talk nonsense about such things, claiming that what he is saying is based in Scripture.  We should do all that we can to avoid such an embarrassing situation, which people see as ignorance in the Christian and laugh to scorn.
 - St. Augustine, De Genesi ad litteram libri duodecim

B

Evangelist, n: A bearer of good tidings, particularly (in a religious sense) such as assure us of our own salvation and the damnation of our neighbours.
Ambrose Bierce

Faith, n. Belief without evidence in what is told by one who speaks without knowledge, of things without parallel.
Ambrose Bierce, The Devil's Dictionary, 1911

Infidel, n: In New York, one who does not believe in the Christian religion; in Constantinople, one who does.
Ambrose Bierce (1842-1914)

Ocean, n: A body of water occupying 2/3 of a world made for man -- who has no gills."
Ambrose Bierce, The Devil's Dictionary, 1911

Pray: To ask that the laws of the universe be annulled in behalf of a single petitioner confessedly unworthy.
Ambrose Bierce

Religion, n: A daughter of Hope and Fear, explaining to Ignorance the Nature of the Unknowable.
Ambrose Bierce, The Devil's Dictionary, 1911

Scriptures: The sacred books of our holy religion, as distinguished from the false and profane writings on which all other faiths are based.
Ambrose Bierce

Accordingly, France Had Voltaire, and his school of negative thinkers, and England (or rather Scotland) had the profoundest negative thinker on record, David Hume:  a man, the peculiarities of whose mind qualified him to detect failure of proof, and want of logical consistency, at a depth which French skeptics, with their comparatively feeble powers of analysis and abstractions stop far short of, and which German subtlety alone could thoroughly appreciate, or hope to rival. 

Bentham, John Stuart Mill, Bentham, London) and Westminster Review, Aug. 1938, revised in 1959 in Dissertations and Discussions, vol. 1.

What Bacon was to the physical world, Helvetius was to the moral,

Jeremy Bentham, quoted in Thought of Jeremy Bentham, p.79.

They call him benevolent in words, but they do not mean that he is so in reality.... For if they did, they would recognise that the dictates of religion could be neither more nor less than the dictates of utility:  not a little different: not a little less or more. But the case is, that on a thousand occasions, they turn their backs on the principle of utility

Bentham, id. 86.

If I had to choose a religion, the sun as the universal giver of life would be my god."
Napoleon Bonaparte

The idea that a good God would send people to a burning Hell is utterly
damnable to me. The ravings of insanity! Superstition gone to seed!
I don't want to have anything to do with such a God. No avenging
Jewish God, no satanic devil, no fiery hell is of any interest to me."
Luther Burbank, address to Science League of San Francisco, Dec. 1924

C

History aside, the almost universal opinion that one's own religious convictions are the reasoned outcome of a dispassionate evaluation of all the major alternatives is almost demonstrably false for humanity in general. If that really were the genesis of most people's convictions, then one would
expect the major faiths to be distributed more or less randomly or evenly over the globe. But in fact they show a very strong tendency to cluster...which illustrates what we all suspected anyway: that social forces are the primary determinants of religious belief for people in general. To decide scientific questions by appeal to religious orthodoxy would therefore be to put social
forces in place of empirical evidence...
Paul Churchland,"_Matter and Consciousness: A Contemporary Introduction to the Philosophy of Mind  {jk’s philosophy professor, Graduate Studies, U of Manitoba, 1970)

Sensible and responsible women do not want to vote. The relative positions to be assumed by man and woman in the working out of our civilization were assigned long ago by a higher intelligence than ours.
Grover Cleveland, 1905

The belief in a supernatural source of evil is not necessary; men alone are quite capable of every wickedness.
Joseph Conrad

D

I had no intention to write atheistic, but I own that I cannot see as plainly as others do, and I should wish to do, the evidence of beneficence and design on all sides as there seems to be too much misery in the world.  I cannot persuade myself that a beneficent god would have designedly created the Ignomonidi to feed inside the body of a caterpillar or that the cat should play with mice.

Charles Darwin in a letter to Prof. Asa Gray.

Let appears to me (whether rightly or wrongly) that direct arguments against Christianity and theism produce hardly any effect on the public; and freedom of thought is best promoted by the gradual illumination of men’s minds which follows from the advance of science. It has, therefore, been always my object to avoid writing on religion, and I have confined myself.

Charles Darwin to Edward Aveling. letter 1880

I can hardly see how anyone ought to wish Christianity to be true; for if so the plain language of the text seems to show that the men who do not believe, and this would include my Father, Brother and almost all my best friends, will be everlastingly punished. And this is a damnable doctrine."
Charles Darwin

I believe the spreading of Catholicism to be the most horrible means of political and social degradation left in the world.
Charles Dickens

To prove the Gospels by a miracle is to prove an absurdity by something contrary to nature."
Denis Diderot

If God were suddenly condemned to live the life which he has inflicted upon men, He would kill himself.
Alexander Dumas

E

My mind is incapable of conceiving such a thing as a soul. I may be in error, and man may have a soul; but I simply do not believe it."
Thomas Edison, "Do We Live Again?"

I do not believe in immortality of the individual, and I consider ethics to be an exclusively human concern with no superhuman authority behind it.
Albert Einstein

Although I cannot believe that the individual survives the death of his body, feeble souls harbor such thought through fear or ridiculous egotism.
 Albert Einstein

"From the viewpoint of a Jesuit priest I am, of course, and have always been an atheist.... I have repeatedly said that in my opinion the idea of a personal God is a childlike one. You may call me an agnostic, but I do not share the crusading spirit of the professional atheist whose fervor is mostly due to a painful act of liberation from the fetters of religious indoctrination received in youth. I prefer an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our being."

Einstein, letter to a soldier during WWII, reprinted in Skeptic, vol. 5, no. 2, 1997, pp. 62ff.

"God does not play dice with the universe."
 - Albert Einstein

"Black holes would seem to suggest that God not only plays dice, but also sometimes throws them where they cannot be seen."
  - Stephen Hawking, NATURE, 1975

Is God willing to prevent evil, but not able? Then he is not omnipotent.
Is he able, but not willing? Then he is malevolent.
Is he both able and willing? Then whence cometh evil?
Is he neither able nor willing? Then why call him God? Epicurus

How it may be Lawful and Fitting to use Falsehood as a Medicine, and for the Benefit of those who Want to be Deceived

Bishop Eusebius (book 12, chapter 32).

We shall introduce into this history in general only those events which may be useful first to ourselves and afterwards to posterity.

Bishop Eusebius (Vol. 8, chapter 2)

F

Prayers never bring anything... They may bring solace to the sap, the bigot, the ignorant, the aboriginal, and the lazy - but to the enlightened it is the same as asking Santa Claus to bring you something for Xmas
- W. C. Fields

Neither in my private life nor in my writings, have I ever made a secret of being an out-and-out unbeliever.
Sigmund Freud, letter to Charles Singer

Religion is comparable to a childhood neurosis.
Sigmund Freud, "Future of an Illusion"

At the bottom God is nothing more than an exalted father.
Sigmund Freud

G

Those who are enslaved to their sects are not merely devoid of all sound knowledge, but they will never even stop to learn.
Galen

To command the professors of astronomy to confute their own observations is to enjoin an impossibility, for it is to command them not to see what they do see, and not to understand
what they do understand, and to find what they do not discover.
Galileo Galilei, "The Authority of Scripture in Philosophical Controversies

The Bible tells you how to go to heaven, not how the heavens go.

Galileo

I do not feel obliged to believe that same God who endowed us with sense, reason, and intellect had intended for us to forgo their use.
Galileo

H

Scientific education end religious educations are incompatible.  The clergy have ceased to interfere with education at the advanced state, with which I am directly concerned, but they have still got control of that of child­ren.  This means that children have to learn about Adam and Noah instead of Evolution; about David who killed Goliath, instead of Koch who killed Cholera; about Christ’s ascent into heaven instead of Montgolfier’s and Wright’s.  Worse than that, they are taught that it is a virtue to accept statements without adequate evidence, which leaves them a prey to quacks of every kind in later life, and makes it very difficult for them to accept the methods of though which are successful in science.

J.B.S. Haldane

A man who believes that he eats his God we do not call mad; yet, a man who says he is Jesus Christ, we call mad.
-Claude A. Helvetius (1715-1771)

I believe today that I am acting in the sense of the Almighty Creator. By warding off the Jews, I am fighting for the Lord's work.

Adolph Hitler, Reichstag speech in 1938

Catholics and Protestants are fighting with one another... while the enemy of Aryan humanity and all Christendom is laughing up his sleeve."
Adolph Hitler, Mein Kampf, pp.309

"Any violence which does not spring from a spiritual base, will be wavering and uncertain. It lacks the stability which can only rest in a fanatical outlook."
Adolph Hitler, Mein Kampf p. 171

"What we have to fight for...is the freedom and independence of the fatherland, so that our people may be enabled to fulfill the mission assigned to it by the Creator."
Adolph Hitler, Mein Kampf, pp. 125

"I am now as before a Catholic and will always remain so"
Adolph Hitler, to Gen. Gerhard Engel, 1941

Malt’s done more than Milton can,

To show God’s way to man.—A.E. Housman

What to me is dark, illumine

What is low raise and support

That to the height of this great argument

I may assert eternal providence

And justify the ways of God

Milton, Bk. I, Paradise Lost

"...but I would still reply, that the knavery and folly of men
are such common phenomena, that I should rather believe the most
extraordinary events to arise from their concurrence, than admit
of so signal a violation of the laws of nature."
An Essay Concerning Human Understanding, David Hume, 10:2:30

"The Christian religion not only was at first attended with miracles, but
even at this day cannot be believed by any reasonable person without one."
David Hume, An Enquiry Concerning Human Understanding, 1748
"No testimony is sufficient to establish a miracle, unless the
testimony be of such a kind, that its falsehood would be more
miraculous than the fact which it endeavors to establish."
David Hume, "Of Miracles", from An Enquiry Concerning Human Understanding, 1748

"The many instances of forged miracles, and prophecies, and supernatural
events, which, in all ages, have either been detected by contrary evidence,
or which detect themselves by their absurdity, prove sufficiently the strong
propensity of mankind to the extraordinary and marvellous, and ought
reasonably to begat a suspicion against all relations of this kind."
David Hume, "Enquiry Concerning Human Understanding" 1748

I

"Salvation through slavery is worthless
Salvation from slavery is inestimable."
[Robert G. Ingersoll, "The Gods", 1872

The notion that faith in Christ is to be rewarded by an eternity of bliss, while a dependence upon reason, observation, and experience merits everlasting pain, is too absurd for refutation, and can be believed only by that unhappy mixture of insanity and ignorance called 'faith.'
-Robert G. Ingersoll

J

They [the clergy] believe that any portion of power confided to me, will be exerted in opposition to their schemes. And they beleive rightly: for I have sworn upon the altar of God eternal hostility against every form of tyranny over the mind of man.
- Thomas Jefferson

I have recently been examining all the known superstitions of the world, and do not find in our particular superstition (Christianity) one redeeming feature. They are all alike founded on fables and mythology." --Thomas Jefferson

K

If God has created all things, and He knows the consequences of its creation, it would be better for His reputation if He remains hidden.

Jerry Kahn

L

If the liberties of the American people are ever destroyed, they will fall by the hands of the clergy.
-General Marquis De Lafayette, 1789

I have no need for that hypothesis.

Leplace.  His reply when asked by Napoleon Bonaparte about Laplace’s 4 volume Celestial Mechanics which lacked any reference to the “author” of the universe. 

"It is quite unlawful to demand, defend, or to grant unconditional freedom of thought, or speech, of writing or worship, as if these were so many rights given by nature to man."
[Pope Leo XIII, "Great Encyclical Letters",16

"I find every sect, as far as reason will help them, make use of it gladly; and where it fails them, they cry out, It is a matter of faith, and above reason."
[John Locke

"The poor wretches have convinced themselves that they are going to be immortal and live for all time, by worshipping that crucified sophist and living under his laws...they receive these doctrines by tradition, without any definite evidence. So if any charlatan or trickster comes among them,
he quickly acquires wealth by imposing upon these simple people."
Lucian, Roman-Syrian writer & lecturer

"If God is all powerful, he can do everything.  He can make a stone so heavy that even he can't lift it. Then there is something God cannot do, he cannot lift the stone. Therefore an all powerful God does not exist."
Lucretius, Roman poet, Epicurean

Idiots, the lame, the blind, the dumb, are men in whom the devils have established themselves: and all the physicians who heal these infirmities, as though they proceeded from natural causes, are ignorant blockheads.
Martin Luther (1483-1546) German Protestant leader

Therefore be on your guard against the Jews, knowing that wherever they have their synagogues, nothing is found but a den of devils in which sheer self-­glory, conceit, lies, blasphemy, and defaming of God and men are practiced most maliciously and veheming his eyes on them.

Martin Luther, The Lies of the Jews, 1543

...but then eject them [Jews] forever from this country. For, as we have heard, God's anger with them is so intense that gentle mercy will only tend to make them worse and worse, while sharp mercy will reform them but little. Therefore, in any case, away with them!                                                                        Luther, supra.

I brief, dear princes and lords, those of you who have Jews under your rule­­ if my counsel does not please you, find better advice, so that you and we all can be rid of the unbearable, devilish burden of the Jews, lest we become guilty sharers before God in the lies, blasphemy, the defamation, and the curses which the mad Jews indulge in so freely and wantonly against the person of our Lord Jesus Christ, this dear mother, all Christians, all authority, and ourselves. Do not grant them protection, safe ­conduct, or communion with us. . . .

Luther, Supra.

First to set fire to their synagogues or schools and to bury and cover with dirt whatever will not burn, so that no man will ever again see a stone or cinder of them. This is to be done in honor of our Lord and of Christendom, so that God might see that we are Christians, and do not condone or knowingly tolerate such public lying, cursing, and blaspheming of his Son and of his Christians

Luther, supra.

Third, I advise that all their prayer books and Talmudic writings, in which such idolatry, lies, cursing and blasphemy are taught, be taken from them. (remainder omitted)                              Martin Luther, supra.