This paper criticizes three central traditions in Marxist accumulation theory on grounds that each relies upon the assumption that the accumulation process is shaped by an ultimate determinant or essence. In the stagnation argument, formulated by J. Steindl (1976, 1979) and P. Baran and P. M. Sweezy (1966), capitalist firms are shaped by an urge to expand which in turn shapes economic growth. E. Mandel's (1980) long-wave theory formulates abstractly fixed inner "laws of motion." The social structures long-wave theory of D. Gordon, R. Edwards, and M. Reich (1982) roots accumulation's pace in abstractly theorized power dynamics. The paper suggests a nonreductionist alternative understanding of Marxist economic theory.