I ask you to look both ways. For the road to a knowledge of the stars leads through the atom; and important knowledge of the atom has been reached through the stars.

Science is one thing, wisdom is another. Science is an edged tool, with which men play like children, and cut their own fingers.

It is one thing for the human mind to extract from the phenomena of nature the laws which it has itself put into them; it may be a far harder thing to extract laws over which it has no control. It is even possible that laws which have not their origin in the mind may be irrational, and we can never succeed in formulating them.

For the truth of the conclusions of physical science, observation is the supreme Court of Appeal.

On one occasion when [William] Smart found him engrossed with his fundamental theory, he asked Eddington how many people he thought would understand what he was writing-after a pause came the reply, 'Perhaps seven.'

Philosophically, the notion of a beginning of the present order of Nature is repugnant to me ... I should like to find a genuine loophole.

Every body continues in its state of rest or uniform motion in a straight line, except insofar as it doesn't.