Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third.

There is no sadder sight in the world than to see a beautiful theory killed by a brutal fact.

Size is not grandeur, and territory does not make a nation.

In scientific work, those who refuse to go beyond fact rarely get as far as fact.

Not only do I disbelieve in the need for compensation, but I believe that the seeking for rewards and punishments out of this lifeleads men to a ruinous ignorance of the fact that their inevitable rewards and punishments are here.

I have always been, am, and propose to remain a mere scholar. All that I have ever proposed to myself is to say, this and this I have learned; thus and thus have I learned it; go thou and learn better; but do not thrust on my shoulders the responsibility for your own laziness if you elect to take, on my authority, conclusions the value of which you ought to have tested for yourself.

People may talk about intellectual teaching, but what we principally want is the moral teaching.