A discovery is generally an unforeseen relation not included in theory.

A man of science rises ever, in seeking truth; and if he never finds it in its wholeness, he discovers nevertheless very significant fragments; and these fragments of universal truth are precisely what constitutes science.

Feeling alone guides the mind.

Proof that a given condition always precedes or accompanies a phenomenon does not warrant concluding with certainty that a given condition is the immediate cause of that phenomenon. It must still be established that when this condition is removed, the phenomen will no longer appear.

The experimenter who does not know what he is looking for will not understand what he finds.

But while I accept specialization in the practice, I reject it utterly in the theory of science.

First causes are outside the realm of science.