Jeroen

“The belief that science proceeds from observation to theory is still so widely and so firmly held that my denial of it is often met with incredulity. I have even been suspected of being insincere- of denying what nobody in his senses would doubt.
But in fact the belief that we can start with pure observation alone, without anything in the nature of a theory is absurd; as may be illustrated by the story of the man who dedicated his life to natural science, wrote down everything he could observe, and bequeathed his priceless collection of observations to the Royal Society to be used as evidence. This story should show us that though beetles may profitably be collected, observations may not.
Twenty-five years ago I tried to bring home the same point to a group of physics students in Vienna by beginning a lecture with the following instructions : 'Take pencil and paper; carefully observe, and write down what you have observed!' They asked, of course, what I wanted them to observe. Clearly the instruction, 'Observe!' is absurd. (It is not even idiomatic, unless the object of the transitive verb can be taken as understood.) Observation is always selective. It needs a chosen object, a definite task, an interest, a point of view, a problem. And its description presupposes a descriptive language, with property words; it presupposes similarity and classification, which in their turn presuppose interests, points of view, and problems.”
― Karl R. Popper, Conjectures and Refutations: The Growth of Scientific Knowledge

“But the secret of intellectual excellence is the spirit of criticism ; it is intellectual independence. And this leads to difficulties which must prove insurmountable for any kind of authoritarianism. The authoritarian will in general select those who obey, who believe, who respond to his influence. But in doing so, he is bound to select mediocrities. For he excludes those who revolt, who doubt, who dare to resist his influence. Never can an authority admit that the intellectually courageous, i.e. those who dare to defy his authority, may be the most valuable type. Of course, the authorities will always remain convinced of their ability to detect initiative. But what they mean by this is only a quick grasp of their intentions, and they will remain for ever incapable of seeing the difference.”
― Karl R. Popper, The Open Society and Its Enemies - Volume One: The Spell of Plato