"Don't be deceived when they tell you things are better now. Even if there's no poverty to be seen because the poverty's been hidden. Even if you ever got more wages and could afford to buy more of these new and useless goods which industries foist on you and even if it seems to you that you never had so much, that is only the slogan of those who still have much more than you.
Don't be taken in when they paternally pat you on the shoulder and say that there's no inequality worth speaking of and no more reason to fight because if you believe them they will be completely in charge in their marble homes and granite banks from which they rob the people of the world under the pretence of bringing them culture.
Watch out, for as soon as it pleases them they'll send you out to protect their gold in wars whose weapons, rapidly developed by servile scientists, will become more and more deadly until they can with a flick of the finger tear a million of you to pieces."
- – Attributed to Jean Paul Marat (May 24, 1743 – July 13, 1793), but likely from Paul Weiss' play Marat/Sade
(BTW, if anyone has a direct source for this quote, I'd love the precise reference.)
(Please check the comments for discussion of attribution.)