Quote by Henri Poincaré
I love the following quote by French mathematician Henri Poincaré (1854-1912). I’m not sure what the original source is, but it is cited in the introduction to The Divine Proportion (1970) by H.E. Huntley.
The mathematician does not study pure mathematics because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.