Engels, in his preface to Capital, Volume 3, as part of his running commentary on &dquo;determinist&dquo; Marxists, warned that the reader should not expect to find &dquo;fixed, cut-to-measure, once and for all applicable definitions in Marx's works&dquo;: It is self-evident that where things and their interrelations are conceived, not as fixed, but as changing, their mental images, the ideas, are likewise subject to change and transformation, and they are not encapsulated in rigid definitions, but are developed in their historical or logical process of formation. [Marx, 1967b: 13-14] According to Engels, then, Marx's terms are meant to express a conception of things and their interrelations-&dquo;not as fixed, but as changing&dquo;-and, consequently, the definitions of these terms must also change. This usage of terms led Pareto to comment that [126] Marx's words are like bats: one can see in them both birds and mice (Ollman, 1971: 3). Accordingly, when Marx laid out his materialist conception of history in his &dquo;Preface&dquo; to A Contribution to the Critique of Political Economy, he stated that the &dquo;mode of production&dquo; determines &dquo;the general process of social, political and intellectual life&dquo; (Marx, 1971: 20-21). Yet, on the very same page, the same &dquo;determining&dquo; role is attributed to &dquo;relations of production,&dquo; &dquo;economic conditions of production,&dquo; &dquo;productive forces,&dquo; &dquo;the economic foundation,&dquo; the &dquo;social forces of production,&dquo; and the &dquo;social conditions of existence.&dquo; These terms not only refer to different things-in the case of &dquo;social conditions of existence&dquo; this is quite clear-but, more important, some of them seem to include in their meaning the parts of society that Marx says they &dquo;determine&dquo; (Ollman, 1971: 6-7). Property relations, as a system of legal claims, for example, come under the heading of &dquo;superstructure,&dquo; but they are also an integral part of the &dquo;relations of production,&dquo; which are part of the &dquo;economic base&dquo; and which in turn &dquo;determine&dquo; the superstructure (Ollman, 1971: 6-7). The same is true for our previous example of the system of credit and national debt in Great Britain's early industrialization. When viewed from one perspective, credit and taxation are merely a set of laws within the legal and political superstructure. Yet how can a system of credit and taxation be clearly separated from the economic base? Does it not clearly include also, within its very definition, the actual workings of an economic system?. ' Until we examine the ways in which Marx conceived of these definitions and categories, his usage of definitions seems at best inconsistent, if not altogether haphazard. For Marx, concepts like &dquo;superstructure,&dquo; &dquo;economic base,&dquo; and &dquo;relations of production&dquo; could not be clearly distinguished and separated from one another because they do not exist, in reality, as separate entities. These conc...