"Our epoch, the epoch of the bourgeoisie, possesses, however, this distinct feature: it has simplified class antagonisms. Society as a whole is more and more splitting up into two great hostile camps, into two great classes directly facing each other — Bourgeoisie and Proletariat."

Marx usage is to refer to the Bourgeoisie as feudalism evolved into capitalism, when bourgeoisie was emerging from the “middle “ between aristocrats and working classes , peasants and newly emerging proletarians. As I’ve said earlier , Engels and Marx make a dialectical reference in the first few paragraphs of the Manifesto, to bourgeois society evolving toward just two classes , bourgeois and proletariat. And 175 years later their prediction has been fulfilled. There are two classes , 99% and 1% , as the “peoples convention” of Occupy Wallstreet brilliantly formulated it . The 1% ( actually.001%) are the Leninist Finance Monopoly Capitalist class . We claim the 99% as the maximum MAJORITY in the Leninist MAJORITIST (Bolshevik in Russian) tradition. We welcome all , even “petit bourgeois “ STRATA ( not class) to our ANTI-Monopoly Coalition ( See CPUSA program for the last 35 years )

"Our epoch, the epoch of the bourgeoisie, possesses, however, this distinct feature: it has simplified class antagonisms. Society as a whole is more and more splitting up into two great hostile camps, into two great classes directly facing each other — Bourgeoisie and Proletariat."

https://www.marxists.org/archive/marx/works/1848/communist-manifesto/ch01.htm#007