Experiment is the sole source of truth.

All the scientist creates in a fact is the language in which he enunciates it. If he predicts a fact, he will employ this language, and for all those who can speak and understand it, his prediction is free from ambiguity. Moreover, this prediction once made, it evidently does not depend upon him whether it is fulfilled or not.

Later generations will regard Mengenlehre (set theory) as a disease from which one has recovered.

Guessing before proving! Need I remind you that it is so that all important discoveries have been made?

Experiment is the sole source of truth.

Intuition is more important to discovery than logic.

All that is not thought is pure nothingness; since we can think only thoughts, and all the words we use to speak of things can express only thoughts, to say there is something other than thought is therefore an affirmation which can have no meaning.