The hypothesis may be put forward to be tested by the s subsequent investigation that this development has been in large part a matter of the reciprocal interaction of new factual insights and knowledge on the one hand with changes in the theoretical system on the other.

It is that of increasing knowledge of empirical fact intimately combined with changing interpretations of this body of fact - hence changing general statements about it - and not least a changing a structure of the theoretical system.

It is probably safe to say that all the changes of factual knowledge which have led to the relativity theory resulting in a very great theoretical development are completely trivial from any point of view except their relevance to the structure of a theoretical system.

From all this it follows what the general character of the problem of the development of a body of scientific knowledge is in so far as it depends on elements internal to science itself.

But the scientific importance of a change in knowledge of fact consists precisely in j its having consequences for a system of theory.

Lack of knowledge... that is the problem.

You should not ask questions without knowledge.

With all the knowledge and skill acquired in thousands of flights in the last ten years I would hardly think today of making my first flight on a strange machine in a twenty-seven mile wind even if I knew that the machine had already been flown and was safe.

Knowledge is power if you know it about the right person.

Real-life people are often the hardest to play people that you recreate who have actually lived because you have to live up to people's knowledge of those characters.