Slaves were property and serfs were required to give most of their crops and labor to their landowners, but even they "guaranteed subsistence” that a proletariat did not guarantee, according to Engels’ “Project of Communist Confession of Faith”. The serf could work harder to increase his share of the harvest, but no matter how hard the proletariat worked, his wages would remain the same. The proletariat was not owned as the slave of a single master, but figuratively speaking, the proletariat was the slave of the bourgeois class, if they did not work, they did not eat.