The immense majority of intellectually eminent men disbelieve in the Christian religion, but they conceal the fact in public, because they are afraid of losing their incomes.

Our use of the phrase 'The Dark Ages' to cover the period from 600 to 1000 marks our undue concentration on Western Europe. [...] From India to Spain, the brilliant civilisation of Islam flourished. What was lost to Christendom at this time was not lost to civilisation, but quite the contrary. [...] To us it seems that West-European civilisation is civilisation, but this is a narrow view.

Collective wisdom, alas, is no adequate substitute for the intelligence of individuals. Individuals who opposed received opinions have been the source of all progress, both moral and intellectual. They have been unpopular, as was natural.

None but a coward dares to boast that he has never known fear.

3 is prime, 5 is prime, 7 is prime, 9 is a paradox; as is a paradox why the number 1 is not prime if it has no other divisors besides himself.

If any philosopher had been asked for a definition of infinity, he might have produced some unintelligible rigmarole, but he would certainly not have been able to give a definition that had any meaning at all.

If there were in the world today any large number of people who desired their own happiness more than they desired the unhappiness of others, we could have a paradise in a few years.