What a monument of human smallness is this idea of the philosopher king. What a contrast between it and the simplicity of humaneness of Socrates, who… - Karl Popper

There are uncertain truths — even true statements that we may take to be false — but there are no uncertain certainties. Since we can never know anything for sure, it is simply not worth searching for certainty; but it is well worth searching for truth; and we do this chiefly by searching for mistakes, so that we have to correct them.

First, it must be admitted that certain forms of behaviour may be described as more ‘natural’ than other forms; for instance, going naked or eating only raw food; and some people think that this in itself justifies the choice of these forms. But in this sense it certainly is not natural to interest oneself in art, or science, or even in arguments in favour of naturalism. The choice of conformity with ‘nature’ as a supreme standard leads ultimately to consequences which few will be prepared to face; it does not lead to a more natural form of civilization, but to beastliness14. The second criticism is more important. The biological naturalist assumes that he can derive his norms from the natural laws which determine the conditions of health, etc., if he does not naïvely believe that we need adopt no norms whatever but simply live according to the ‘laws of nature’. He overlooks the fact that he makes a choice, a decision; that it is possible that some other people cherish certain things more than their health (for instance, the many who have consciously risked their lives for medical research). And he is therefore mistaken if he believes that he has not made a decision, or that he has derived his norms from biological laws.

One of the ideas I had discussed in The Poverty of Historicism was the influence of a prediction upon the event predicted. I had called this the "Oedipus effect", because the oracle played a most important role in the sequence of events which led to the fulfilment of its prophecy. ... For a time I thought that the existence of the Oedipus effect distinguished the social from the natural sciences. But in biology, too—even in molecular biology—expectations often play a role in bringing about what has been expected.