2 common usages of the concept proletariat are explored. The 1st concept is that advocated by David Lockwood & John H. Goldthorpe, & the 2nd, that purported by Marx. Internal inconsistencies in the theory of Lockwood & Goldthorpe include its uncertain theoretical status, inadequate causal modeling, the gradual change of emphasis in their approach, & "the surreptitious introduction of historical assumptions into what is supposedly a purely sociological ideal-type without historical reference by the use of the word 'traditional'." In Marx's view, the proletariat possesses the power of possibility as well as the negation of possibility. "Such a class has the motive, the means, & the necessity to make a revolution." When the 2 theories of the proletariat are compared it can be discerned that Lockwood & Goldthorpe's proletariat is most like Marx's conception of 'estates.' Neither theory projects a definition of the causal chains constituting the proletariat. The utilization of a positivist or an axiomatic solution do not alleviate or clarify the ambiguities inherent in the 2 theories. "Indeed 'meaning,' as in the case of the proletariat, may be a content of the concept which restarts the problem of translation which we were trying to leave behind." J. Grimes.