An attempt to study the evolution of living organisms without reference to cytology would be as futile as an account of stellar evolution which ignored spectroscopy.

Science is vastly more stimulating to the imagination than the classics.

My practise as a scientist is atheistic. That is to say, when I set up an experiment I assume that no god, angel, or devil is going to interfere with its course; and this assumption has been justified by such success as I have achieved in my professional career. I should therefore be intellectually dishonest if I were not also atheistic in the affairs of the world. And I should be a coward if I did not state my theoretical views in public.

[Children] are taught that it is a virtue to accept statements without adequate evidence, which leaves them a prey to quacks of every kind in later life, and makes it very difficult for them to accept the methods of thought which are successful in science.

The conservative has but little to fear from the man whose reason is the servant of his passions, but let him beware of him in whom reason has become the greatest and most terrible of the passions. These are the wreckers of outworn empires and civilisations, doubters, disintegrators, deicides.

I have come to the conclusion that my subjective account of my motivation is largely mythical on almost all occasions. I don't know why I do things.

Science is as yet in its infancy, and we can foretell little of the future save that the thing that has not been is the thing that shall be; that no beliefs, no values, no institutions are safe.