Letter to Bessel (1826), quoted in Dunnington, G. Waldo. "Gauss, His Disquisitiones Arithmeticae, and His Contemporaries in the Institut de France." … - Carl Friedrich Gauss

Allein die Schule des Lebens muss lehren, nur das Erreichbare zu wollen, und das Gute nicht deswegen zu verschmähen, weil noch etwas Besseres denkbar ist.

Even though much error and hypocrisy may often be mixed in such pietistic tendencies, nevertheless I recognize with all my heart the business of a missionary as a highly honorable one in so far as it leads to civilization the still semisavage part of earth s inhabitants. May my son try it for several years.

I will add that I have recently received from Hungary a little paper on non-Euclidean geometry in which I rediscover all my own ideas and results worked out with great elegance... The writer is a very young Austrian officer, the son of one of my early friends, with whom I often discussed the subject in 1798, although my ideas were at that time far removed from the development and maturity which they have received through the original reflections of this young man. I consider the young geometer J. Bolyai a genius of the first rank.