The problem of distinguishing prime numbers from composite numbers and of resolving the latter into their prime factors is known to be one of the most important and useful in arithmetic.

It is not knowledge, but the act of learning, not possession but the act of getting there, which grants the greatest enjoyment.

His second motto: Thou, nature, art my goddess; to thy laws my services are bound.

You know that I write slowly. This is chiefly because I am never satisfied until I have said as much as possible in a few words, and writing briefly takes far more time than writing at length.

The total number of Dirichlet's publications is not large: jewels are not weighed on a grocery scale.

When I have clarified and exhausted a subject, then I turn away from it, in order to go into darkness again.

The problem of distinguishing prime numbers from composite numbers and of resolving the latter into their prime factors is known to be one of the most important and useful in arithmetic. It has engaged the industry and wisdom of ancient and modern geometers to such an extent that it would be superfluous to discuss the problem at length. ... Further, the dignity of the science itself seems to require that every possible means be explored for the solution of a problem so elegant and so celebrated.