“He alone is an acute observer, who can observe minutely without being observed.”

“Nobody could be an observer without being involved.”

“Listen to everything that is said, and see everything that is done. Observe the looks and countenances of those who speak, which is often a surer way of discovering the truth than from what they say. But then keep all those observations to yourself, for your own private use, and rarely communicate them to others. Observe, without being thought an observer, for otherwise people will be upon their guard before you.”

“When K. looked at the castle, often it seemed to him as if he were observing someone who sat quietly there in front of him gazing, not lost in thought and so oblivious of everything, but free and untroubled, as if he were alone with nobody to observe him, and yet must notice that he was observed, and all the same remained with his calm not even slightly disturbed; and really - one did not know whether it was cause or effect - the gaze of the observer could not remain concentrated there, but slid away.”

“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.”

“There are people who observe the rules of honor as one observes the stars, from a great distance.”