The unreasonable efficiency ...

The unreasonable efficiency of mathematics in science is a gift we neither understand nor deserve.
 Eugene Wigner

Quotes from the same author

The world is very complicated and it is clearly impossible for the human mind to understand it completely. Man has therefore devised an artifice which permits the complicated nature of the world to be blamed on something which is called accidental and thus permits him to abstract a domain in which simple laws can be found.
 Eugene Wigner
There is no natural phenomenon that is comparable with the sudden and apparently accidentally timed development of science, except perhaps the condensation of a super-saturated gas or the explosion of some unpredictable explosives.
 Eugene Wigner