By reading the characteristic features of any man's castles in the air you can make a shrewd guess as to his underlying desires which are frustrated.

One might as well say he has sold when no one has bought as to say he has taught when no one has learned.

Scientific principles and laws do not lie on the surface of nature. They are hidden, and must be wrested from nature by an active and elaborate technique of inquiry.

Without initiation into the scientific spirit one is not in possession of the best tools which humanity has so far devised for effectively directed reflection. One in that case not merely conducts inquiry and learning without the use of the best instruments, but fails to understand the full meaning of knowledge.

...the moment of passage from disturbance into harmony is that of intensest life.

The most important attitude that can be formed is that of desire to go on learning.

If we teach today’s students as we taught yesterday’s, we rob them of tomorrow.