No book can ever be finished. While working on it we learn just enough to find it immature the moment we turn away from it.
Every genuine test of a theory is an attempt to falsify it, or to refute it.
Philosophy is a necessary activity because we, all of us, take a great number of things for granted, and many of these assumptions are of a philosophical character; we act on them in private life, in politics, in our work, and in every other sphere of our lives – but while some of these assumptions are no doubt true, it is likely, that more are false and some are harmful. So the critical examination of our presuppositions – which is a philosophical activity – is morally as well as intellectually important.
Always remember that it is impossible to speak in such a way that you cannot be misunderstood: there will always be some who misunderstand you.
I would rather find a single causal law than be the king of Persia!
I hold that he who teaches that not reason but love should rule opens up the way for those who rule by hate.
And it implies that if we respect truth, we must search for it by persistently searching for our errors: by indefatigable rational criticism, and self-criticism.
The Utopian attempt to realize an ideal state, using a blueprint of society as a whole, is one which demands a strong centralized rule of a few, and which is therefore likely to lead to a dictatorship.
Great men may make great mistakes;.
The method of learning by trial and error – of learning from our mistakes – seems to be fundamentally the same whether it is practised by lower or by higher animals, by chimpanzees or by men of science.
What we need and what we want is to moralize politics, not to politicize morals.
Criticism, I said, is an attempt to find the weak spots in a theory, and these, as a rule, can be found only in the more remote logical consequences which can be derived from it. It is here that purely logical reasoning plays an important part in science.
Instead of the greatest happiness for the greatest number, one should demand, more modestly, the least amount of avoidable suffering for all; and further, that unavoidable suffering – such as hunger in times of an unavoidable shortage of food – should be distributed as equally as possible.
I wish to make it clear that ‘history’ in the sense in which most people speak of it simply does not exist; and this is at least one reason why I say that it has no meaning.
The quest for precision is analogous to the quest for certainty, and both should be abandoned.
For nothing could be better than living a modest, simple, and free life in an egalitarian society. It took some time before I recognized this as no more than a beautiful dream; that freedom is more important than equality; that the attempt to realize equality endangers freedom; and that, if freedom is lost, there will not even be equality among the unfree.
The future depends on ourselves, and we do not depend on any historical necessity.
Theology, I still think, is due to lack of faith.
This is why the conflict between rationalism and irrationalism has become the most important intellectual, and perhaps even moral, issue of our time.
Again, we cannot search the whole world in order to make sure that nothing exists which the law forbids. Nevertheless, both kinds of strict statements, strictly existential and strictly universal, are in principle empirically decidable, each, however, in one way only: they are unilaterally decidable. Whenever it is found that something exists here or there, a strictly existential statement may thereby be verified, or a universal one falsified.