xy

It is true that this proviso is hardly necessary as regards the multiplication table, but knowledge in practical affairs has not the certainty or the precision of arithmetic. Suppose I say "democracy is a good thing": I must admit, first, that I am less sure of this than I am that two and two are four, and secondly, that "democracy" is a somewhat vague term which I cannot define precisely. We ought to say, therefore: "I am fairly certain that it is a good thing if a government has something of the characteristics that are common to the British and American Constitutions," or something of this sort. And one of the aims of education ought to be to make such a statement more effective from a platform than the usual type of political slogan.
1940s, Philosophy for Laymen (1946)

“The opinions that are held with passion are always those for which no good ground exists; indeed the passion is the measure of the holder's lack of rational conviction. Opinions in politics and religion are almost always held passionately.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

Source: Introduction to 1961 edition of Sceptical Essays (1961)

“There is one very serious defect to my mind in Christ's moral character, and that is that He believed in hell. I do not myself feel that any person who is really profoundly humane can believe in everlasting punishment.”

Bertrand Russell book Why I Am Not a Christian

"The Moral Problem"
1920s, Why I Am Not a Christian (1927)

“I do not think that the real reason why people accept religion has anything to do with argumentation. They accept religion on emotional grounds. One is often told that it is a very wrong thing to attack religion, because religion makes men virtuous. So I am told; I have not noticed it.”

Bertrand Russell book Why I Am Not a Christian

"The Emotional Factor"
1920s, Why I Am Not a Christian (1927)

“The prospect for the human race is sombre beyond all precedent. Mankind are faced with a clear-cut alternative: either we shall all perish, or we shall have to acquire some slight degree of common sense. A great deal of new political thinking will be necessary if utter disaster is to be averted.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

1940s, The Bomb and Civilization http://personal.kent.edu/~rmuhamma/Philosophy/RBwritings/bombCivilization.htm (1945)

“To conquer fear is the beginning of wisdom.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

“The happiness that is genuinely satisfying is accompanied by the fullest exercise of our faculties and the fullest realization of the world in which we live.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

“Belief in eternal hell fire was an essential item of Christian belief until pretty recent times. In this country, as you know, it ceased to be an essential item because of a decision of the Privy Council, and from that decision the Archbishop of Canterbury and the Archbishop of York dissented; but in this country our religion is settled by Act of Parliament, and therefore the Privy Council was able to override Their Graces and hell was no longer necessary to a Christian. Consequently I shall not insist that a Christian must believe in hell.”

Bertrand Russell book Why I Am Not a Christian

What is a Christian? https://users.drew.edu/~jlenz/whynot.html (1927) <br class="br">1920s, Why I Am Not a Christian (1927)

“It seems that sin is geographical.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

From this conclusion, it is only a small step to the further conclusion that the notion of "sin" is illusory, and that the cruelty habitually practised in punishing it is unnecessary.
A Fresh Look at Empiricism: 1927-42 (1996), p. 283
Attributed from posthumous publications

“One of the symptoms of an approaching nervous breakdown is the belief that one’s work is terribly important. If I were a medical man, I should prescribe a holiday to any patient who considered his work important.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

“Mathematics, rightly viewed, possesses not only truth, but supreme beauty – a beauty cold and austere, like that of sculpture, without appeal to any part of our weaker nature, without the gorgeous trappings of painting or music, yet sublimely pure, and capable of a stern perfection such as only the greatest art can show. The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of highest excellence, is to be found in mathematics as surely as in poetry. What is best in mathematics deserves not merely to be learnt as a task, but to be assimilated as a part of daily thought, and brought again and again before the mind with ever-renewed encouragement.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

1900s, "The Study of Mathematics" (November 1907)

“In fact the opposition of instinct and reason is mainly illusory. Instinct, intuition, or insight is what first leads to the beliefs which subsequent reason confirms or confutes; but the confirmation, where it is possible, consists, in the last analysis, of agreement with other beliefs no less instinctive. Reason is a harmonising, controlling force rather than a creative one. Even in the most purely logical realms, it is insight that first arrives at what is new.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

Source: 1910s, Our Knowledge of the External World (1914), p. 21

“Religion is based, I think, primarily and mainly upon fear. It is partly the terror of the unknown and partly, as I have said, the wish to feel that you have a kind of elder brother who will stand by you in all your troubles and disputes. Fear is the basis of the whole thing – fear of the mysterious, fear of defeat, fear of death. Fear is the parent of cruelty, and therefore it is no wonder if cruelty and religion have gone hand-in-hand. It is because fear is at the basis of those two things. In this world we can now begin a little to understand things, and a little to master them by the help of science, which has forced its way step by step against the Christian religion, against the churches, and against the opposition of all the old precepts. Science can help us to get over this craven fear in which mankind has lived for so many generations. Science can teach us, and I think our own hearts can teach us, no longer to look around for imaginary supports, no longer to invent allies in the sky, but rather to look to our own efforts here below to make this world a fit place to live in, instead of the sort of place that the churches in all these centuries have made it.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

"Fear, the Foundation of Religion"
1920s, Why I Am Not a Christian (1927)