“The methods of increasing the degree of truth in our beliefs are well known; they consist in hearing all sides, trying to ascertain all the relevant facts, controlling our own bias by discussion with people who have the opposite bias, and cultivating a readiness to discard any hypothesis which has proved inadequate.”

“Most men think that in framing their political opinions they are actuated by desire for the public good; but 9 times out of 10 a man’s politics can be predicted from the way in which he makes a living. This has led some people to maintain, and many more to believe practically, that in such matters it is impossible to be objective, and that no method is possible except a tug-of-war between classes with opposite bias.”

“It is amazing how much both happiness and efficiency can be increased by the cultivation of an orderly mind, which thinks about a matter adequately at the right time rather than inadequately at all times. When a difficult or worrying decision has to be reached, as soon as all the data are available, give the matter your best thought and make your decision; having made the decision, do not revise it unless some new fact comes to your knowledge. Nothing is so exhausting as indecision, and nothing is so futile.”

“Noone has yet succeeded in inventing a philosophy at once credible and self-consistent. Locke aimed at credibility, and achieved it at the expense of consistency. Most of the great philosophers have done the opposite. A philosophy which is not self-consistent cannot be wholly true, but a philosophy which is self-consistent can very well be wholly false. The most fruitful philosophies have contained glaring inconsistencies, but for that very reason have been partially true. There is no reason to suppose that a self-consistent system contains more truth than one which, like Locke’s, is more or less wrong.”

“None of our beliefs are quite true; all have at least a penumbra of vagueness and error.”

“Those who have a scientific outlook on human behaviour, moreover, find it impossible to label any action as ‘sin’; they realise that what we do has its origin in our heredity, our education, and our environment, and that it is by control of these causes, rather than by denunciation, that conduct injurious to society is to be prevented.”

“Stupidity and unconscious bias often work more damage than venality.”