Not to be absolutely certain is, I think, one of the essential things in rationality. — Bertrand Russell Copy Share Image
Common sense, however it tries, cannot avoid being surprised from time to time. — Bertrand Russell Copy Share Image
Only mathematics and mathematical logic can say as little as the physicist means to say. — Bertrand Russell Copy Share Image
The rules of logic are to mathematics what those of structure are to architecture. — Bertrand Russell Copy Share Image
I am delighted to know that Principia Mathematica can now be done by machinery. . . I am quite willing to believe… — Bertrand Russell Copy Share Image
Frege has the merit of ... finding a third assertion by recognising the world of logic which is neither mental nor physical. — Bertrand Russell Copy Share Image
Formality Thus the absence of all mention of particular things or properties in logic or pure mathematics is a necessary result of… — Bertrand Russell Copy Share Image
I am allowed to use plain English because everybody knows that I could use mathematical logic if I chose. — Bertrand Russell Copy Share Image
This illustrates an important truth, namely, that the worse your logic, the more interesting the consequences to which it gives rise. — Bertrand Russell Copy Share Image
Analytic It is clear that the definition of "logic" or "mathematics" must be sought by trying to give a new definition of… — Bertrand Russell Copy Share Image
The supreme maxim in scientific philosophising is this: wherever possible, logical constructions are to be substituted for inferred entities. — Bertrand Russell Copy Share Image
“His most important books are his two Logics, and these must be understood if the reasons for his views on other subjects… — Bertrand Russell Copy Share Image
The question of "unreality"is a very important one. Misled by grammar, the great majority of those logicians who have dealt with this… — Bertrand Russell Copy Share Image
Inferences of Science and Common Sense differ from those of deductive logic and mathematics in a very important respect, namely, when the… — Bertrand Russell Copy Share Image
All traditional logic habitually assumes that precise symbols are being employed. It is therefore not applicable to this terrestial life but only… — Bertrand Russell Copy Share Image
A logical theory may be tested by its capacity for dealing with puzzles, and it is a wholesome plan, in thinking about… — Bertrand Russell Copy Share Image
The true function of logic ... as applied to matters of experience ... is analytic rather than constructive; taken a priori, it… — Bertrand Russell Copy Share Image
The fact that all Mathematics is Symbolic Logic is one of the greatest discoveries of our age; and when this fact has… — Bertrand Russell Copy Share Image
“Logic was, formerly, the art of drawing inferences; it has now become the art of abstaining from inferences, since it has appeared… — Bertrand Russell Copy Share Image
Ordinary language is totally unsuited for expressing what physics really asserts, since the words of everyday life are not sufficiently abstract. Only… — Bertrand Russell Copy Share Image
But as the work proceeded I was continually reminded of the fable about the elephant and the tortoise. Having constructed an elephant… — Bertrand Russell Copy Share Image
In the first place a philosophical proposition must be general. It must not deal specially with things on the surface of the… — Bertrand Russell Copy Share Image
“The principle we are examining may be called the principle of induction, and its two parts may be stated as follows: (a)… — Bertrand Russell Copy Share Image
“Pure mathematics consists entirely of assertions to the effect that, if such and such a proposition is true of anything, then such… — Bertrand Russell Copy Share Image
“Ever since Plato most philosophers have considered it part of their business to produce ‘proofs’ of immortality and the existence of God.… — Bertrand Russell Copy Share Image
The conception of the necessary unit of all that is resolves itself into the poverty of the imagination, and a freer logic… — Bertrand Russell Copy Share Image
If the State does not acquire supremacy over [vast private] enterprises, it becomes their puppet, and they become the real State. — Bertrand Russell Copy Share
That the world is in a bad shape is undeniable, but there is not the faintest reason in history to suppose that Christianity offers… — Bertrand Russell Copy Share
Those who advocate common usage in philosophy sometimes speak in a manner that suggests the mystique of the 'common man.' — Bertrand Russell Copy Share
“Such, in outline, but even more purposeless, more void of meaning, is the world which Science presents for our belief. Amid such a world,… — Bertrand Russell Copy Share
Dr. Arnold . . . the admired reformer of public schools, came across some cranks who thought it a mistake to flog boys. Anyone… — Bertrand Russell Copy Share
Of all evils of war the greatest is the purely spiritual evil: the hatred, the injustice, the repudiation of truth, the artificial conflict. — Bertrand Russell Copy Share
Aristotle maintained that women have fewer teeth than men; although he was twice married, it never occurred to him to verify this statement by… — Bertrand Russell Copy Share
If an opinion contrary to your own makes you angry, that is a sign that you are subconsciously aware of having no good reason… — Bertrand Russell Copy Share
I cannot escape from the conclusion that the great ages of progress have depended upon a small number of individuals of transcendent ability. — Bertrand Russell Copy Share
I think it would be just to say the most essential characteristic of mind is memory, using this word in its broadest sense to… — Bertrand Russell Copy Share
The newspapers at one time said that I was dead but after carefully examining the evidence I came to the conclusion that this statement… — Bertrand Russell Copy Share
“Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion.” — Bertrand Russell Copy Share
“Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This… — Bertrand Russell Copy Share
There is no greater reason for children to honour parents than for parents to honour children except, that while the children are young, the… — Bertrand Russell Copy Share
