Mathematics has beauties of its own -- a symmetry and proportion in its
results, a lack of superfluity, an exact adaptation of means to ends,
which is exceedingly remarkable and to be found only in the works of the
greatest beauty When this subject is properly ... presented, the mental
emotion should be that of enjoyment of beauty, not that of repulsion from
the ugly and the unpleasant.
In H. Eves Mathematical Circles Squared, Boston: Prindle, Weber and Schmidt, 1972.