We can't define anything precisely. If we attempt to, we get into that paralysis of thought that comes to philosophers: one saying to the other: 'you don't know what you are talking about!'. The second one says: 'what do you mean by talking? What do you mean by you? What do you mean by know?'

It is important to realize that in physics today, we have no knowledge what energy is. We do not have a picture that energy comes in little blobs of a definite…

From a long view of the history of mankind - seen from, say, ten thousand years from now, there can be little doubt that the most significant event of the 19th…

A great deal more is known than has been proved.

Philosophy is a battle against the bewitchment of our intelligence by means of our language. #109

I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thi…

Faced with the nonsense question 'What is the meaning of a word?' and perhaps dimly recognizing it to be nonsense, we are nevertheless not inclined to give it …