As Leonard Fein pointed out, "The very rich have been well aware of their class privilege and have laboured mightily to protect and defend it".
"[7] As the Industrial Revolution progressed, the sharpening of socioeconomic divisions caused each group to become more acutely conscious of its position in the hierarchy.
Non-Marxists differentiate society's various groups based on social stratification, i.e., income, race, gender, ethnicity, education, occupation, or status.
[12] The Polish political philosopher Leszek Kolakowski disputed the notion that class consciousness could be instilled from outside by a vanguard party.
[13][14] Austrian School economist Ludwig von Mises asserted that "Marx confus[ed] the notions of caste and class".