I see now more clearly than ever before that even our greatest troubles spring from something that is [as] admirable and sound as it is dangerous – from our impatience to better the lot of our fellows.

No particular theory may ever be regarded as absolutely certain.... No scientific theory is sacrosanct.

It is often asserted that discussion is only possible between people who have a common language and accept common basic assumptions. I think that this is a mistake. All that is needed is a readiness to learn from one's partner in the discussion, which includes a genuine wish to understand what he intends to say. If this readiness is there, the discussion wrighteous stupidityill be the more fruitful the more the partner's backgrounds differ.

We do not know. We can only guess.

Propose theories which can be criticized. Think about possible decisive falsifying experiments-crucial experiments. But do not give up your theories too easily-not, at any rate, before you have critically examined your criticism.

Better our hypotheses die for our errors than ourselves.

Plato felt that a complete reconstruction of society's political program was needed.