For real wealth is the developed productive power of all individuals. The measure of wealth is then not any longer, in any way, labour time, but rather disposable time.
Nothing can have value without being an object of utility.
The ruling ideas of each age have ever been the ideas of its ruling class.
Revolutions are the locomotives of history.
The production of too many useful things results in too many useless people.
The history of all previous societies has been the history of class struggles.