I don't recall Silvio saying that, but what do I know, I am the one not paying attention lately, remember? <bg>
That quote is a classic, I do remember a few more though:
"Finance is a gun, Politics is knowing when to pull the trigger." Lucchesi's answer to Vincent's question of how finances and politics work together.
This one is actually very funny, "He should be careful, it is dangerous to be an honest man." in reference to the Pope and the changes he was introducing.