That's Xunzi, not Confucius. Good quote though.
</chinese geek>
http://en.wikiquote.org/wiki/Xun_Zi doesn't seem to have it; perhaps an update's required?
Check out: http://www.barrypopik.com/index.php/new_york_city/entry/tell...
it has a bunch of translations and transliterations of this quote.
Confucius