Pause you who read this, and think for a moment of the long chain of iron or gold, of thorns or flowers, that would never have bound you, but for the formation of the first link on one memorable day.
Everyone can recognize history when it happens. Everyone can recognize history after is has happened; but only the wise man knows at the moment what is vital and permanent, what is lasting and memorable.
It is true that the grasping of truth is not possible without empirical basis. However, the deeper we penetrate and the more extensive and embracing our theories become the less empirical knowledge is needed to determine those theories.
The scientific theorist is not to be envied. For Nature, or more precisely experiment, is an exorable and not very friendly judge of his work. It never says "yes" to a theory. In the most favorable cases it says "Maybe," and in the great majority of cases simply "No." If an experiment agrees with a theory it means for the latter "Maybe," and if it does not agree it means "No." Probably every theory will some day experience its "No" - most theories, soon after conception.