This notoriously elusive and multifaceted notion assumed importance in the history of political economy because Marx's "critique of political economy", Capital, and particularly its first draft, the Grundrisse of 1857–8, was presented in a dialectical form. Part of the difficulty of encapsulating the dialectic within any concise definition derives from the fact that it may be conceived as a method of thought, a set of laws governing the world, the immanent movement of history or any combination of the three. The dialectic originated in ancient Greek philosophy. The original meaning of "dialogos" was to reason by splitting in two. In one form of its development, dialectic was associated with reason. Starting with Zeno's paradoxes, dialectical forms of reasoning were found in most of the philosophies of the ancient world and continued into medieval forms of disputation. It was this form of reasoning that Kant attacked in his distinction between the logic of understanding which, applied to the data of sensation, yielded knowledge of the phenomenal world, and dialectic or the logic of reasoning, which proceeded independently of experience and purported to give knowledge of the transcendant order of things in themselves. In another form of dialectic, the focus was primarily upon processes: either an ascending dialectic in which the existence of a higher reality is demonstrated, or in a descending form in which this higher reality is shown to manifest itself in the phenomenal world. Such conceptions were particularly associated with Christian eschatology, neo-platonism and illuminism, and typically patterned themselves into conceptions of original unity, division or loss, and ultimate reunification.