I'm looking for interesting and/or expressive quotations from mathematicians about the class number formula. I'm interested both in quotations from historical mathematicians and from modern mathematicians. I'm also interested in quotations about generalizations of the class number formula.

I'll start off by giving one, paraphrasing from Henri Darmon and Claude Levesque's article titled [Infinite sums, diophantine equations and Fermat's Last Theorem][1] (pages 4-6):

> Let $N_p$ be the number of solutions
> to $x^2 + y^2 = 1$ over
> $\mathbb{F_p}$, let $N_{\mathbb{Z}}$
> be the number of solutions over
> $\mathbb{Z}$ and let $N_\mathbb{R}$ be
> the circumference of the circle.  From
> quadratic reciprocity, Leibniz's
> formula, and the Euler product formula
> we deduce $\displaystyle \prod_{p}
> \frac{N_p}{p} = \frac{4}{\pi}$. We
> conclude that $\displaystyle \prod_{p}
> \frac{N_p}{p} \cdot N_{\mathbb{R}} =
> 2N_{\mathbb{Z}}$. This magical formula
> shows that the numbers $N_p$ "know"
> the behavior of the equation over the
> real numbers. Fundamentally, this is
> only a simple reinterpretation of
> Leibniz's formula, but in fact this is
> quite a fruitful one.


  [1]: http://www.math.mcgill.ca/darmon/pub/Articles/Surveys/1.Levis/englishpaper.pdf