I read his book The Prince years ago in a course about political philosophy. Here’s a quote from The New York Times weblog Dot Earth (Andrew Revkin):

“It must be considered that there is nothing more difficult to carry out, nor more doubtful of success, nor more dangerous to handle, than to initiate a new order of things. For the reformer has enemies in all those who profit by the old order, and only lukewarm defenders in all those who would profit by the new order, this lukewarmness arising partly from fear of their adversaries, who have the laws in their favor; and partly from the incredulity of mankind, who do not truly believe in anything new until they have had actual experience of it.” — The Prince.

Thanks to Loretta Lohman for the link.