One of capitalism's greatest coups and most resounding victories has been the successful combination of both the master and slave mentalities within nearly every individual among the working classes of the population. Under the current capitalist system, each person has become their own master—has become their own slave.
Under the old system, the slave was made to work so that the master might have material abundance. The master had ample time to enjoy this abundance, since s/he did not have to spend her/his time working—that was the slaves' job. From the capitalist perspective, this type of system presents a problem in that the amount of goods the master and his/her household can consume is relatively limited, even in the most opulent cases. Additionally, resources devoted to the maintenance of slaves are unavailable for use by the capitalist.
Were there more masters to purchase goods from the capitalist, the slave system would not present such a problem—but more masters would also require more slaves to serve them which would, in turn, reduce the amount of resources available to the capitalist and impede his/her ability to take advantage of this larger market of masters. What to do?
The Capitalist system has solved this problem quite elegantly, by replacing the external, interpersonal master/slave division with an internal, intra-personal one. This has had the result of increasing the number masters, who can purchase the output of the capitalist process, without increasing the number of slaves needed to sustain them, thus leaving resources plentiful and inexpensive for capitalist exploitation.
While this solution has proven quite useful for the capitalists, the effects on the working classes have been less salubrious. Whereas, in the former system the master had ample time to enjoy the material abundance provided by his/her slaves, the new master/slave hybrid does not have the same luxury. Being also his/her own slave, this new type of person is expected to both work like a slave and to have material abundance, like a master. The abundance is in vain, however, as being also a slave, he/she lacks adequate time with which to enjoy the abundance that slavery produces.
The result for the working-class master/slave is an unquiet conscience. Whereas a mere slave knew better than to seek fulfillment in material possessions, the master/slave hybrid is imbued with no such wisdom. S/he has adopted the value system of the master and so seeks fulfillment in material wealth, but is unable to enjoy it due to the constant lashing of the slave aspect of the self—to drive it to work harder to provide more wealth for the master aspect. This disjointed self of the modern working-class human, enmeshed in capitalist society, far from representing an overcoming of the previous slave-based economy, is rather the pinnacle of its ascendancy.
Under the old system, the slaves would sometimes rebel against their masters, turning against their overseers and disrupting the entire system of wealth extraction. The new system is superior in this regard—at least from the point of view of the capitalists—in that revolt against one's own self is infinitely more difficult than rebellion against an external authority. Thus, disruptions are kept to a minimum in the new system of slavery, where every man is his own servant, every woman her own oppressor.