[Marxism] If you want to identify the ruling class, you have to decide what is a social class.

[johnaimani]

Ask any 'Marxist' how is it that class is determined and she/he will no doubt aver "Class is determined by ones relationship to the means of production".  Ask them what that means and they can't tell you.  These is a scientific analysis of class and that is that class is determined by the value-composition of the product one sells.

The constituents of value are c + v + s.  

Now c + v, in the hands of the capitalist, equal C (for Capital that can be used to purchase constant  (c) and varariable (v) capitals).

And v + s, when controlled by the worker, equal l (for the full value of the labor of the worker.). 

We are then led to this formulation of the classes:

Working Classes

    Wage-worker - v (the wage worker has only hir's labor-power (v)  to sell)

    Independent worker - c + l (the IW must have hir's own means of production (c) and owns the full value of hir's labor (l)

    Petit-Bourgeois - (c + l) + (v + s) (the PB owns the constant capital hir uses (c) and hir's own labor (l) + purchase the labor-power of hir's workers (v) and             owns the surplus produced by the worker (s))

Capitalist Classes

    Petit-Bourgeois - (c + l) + (v + s) (the PB owns the constant capital hir uses (c) and hir's own labor (l) + purchase the labor-power of hir's workers (v)                 and owns the surplus produced by the worker (s))

    Capitalist - C

        Industrial - (Cp) where p stands for enterprise profit
        Rent - (Cg) where g stands for ground-rent
        Financial - (Ci) where i stands for interest

It will be noted above that the PB lies in both classes, or rather is a hybrid of both classes.  This is so because hir's own labor (l) is necessary  to maintain hir (i.e. hir can neither maintain hir's position solely by hir's own work (in that case hir would be an IW); nor can hir maintain that position solely by exploiting wage-labor (in that case hir would be a capitalist).