
In his introduction to The Presocratics, Philip Wheelwright makes a rather profound point in the course of a brief aside. He's just finished explaining the significance of Anaximander's cosmological breakthrough - the philosopher proposed that "the earth is poised at the center of the universe, held in place by the fact that the universe extends equally on all sides of it," an incredibly novel theory given that his teacher, Thales, believed that the earth merely floated on interminable waters, thus suggesting an absolute up-down gravitational relation in contrast to Anaximander's more sophisticated notion of gravitational equipoise - when his attentions turn, momentarily, to a more characteristically modern question of social episteme and discourse. Wheelwright remarks that, despite the revolutionary import of Anaximander's astrological thesis, subsequent Greek philosophers continued to speak in terms of a "Way Up" and "Way Down," describing those cosmological parameters delineated by the Thalesian view. In offering a brief explanation for this discursive anachronism, Wheelwright explains, "Overt cosmological doctrines were, then as now, often combined with habits of thought and idiom drawn from another source." This other source, of course, is the pre-revolutionary past; the epistemological strata which survives its own refutation through a sort of discursive inertia.
However, the dimensions of this argument take a slightly different form if we apply it to Wheelwright's subsequent discussion of ontology among the Presocratics. Wheelwright argues that the "general ontological question of 'What?' is never a pure question: it rests upon certain assumptions as to the kinds of answer that are possible or acceptable." Here, Wheelwright again appeals to discursive limitations, though in a more radical manner. He explains:
Suppose that someone today, theorizing about the essential nature of things, were to propose the view that everything is ultimately electricity, or nuclear energy, or something of that sort: a listener, even if he were to reject the answer as too narrow, or even to dismiss the query as futile, would still regard the answer as making a kind of sense; but if the theorizer were to propose the answer that everything is ultimately water, or air, or an interplay of qualities like bright, dark, moist, dry, etc., he would generally be dismissed either as a fool or as a poet playing with fancies.

A new discursive force is identified, one which opposes the inertia previously described with regard to cosmological views. In approaching ontological questions, Wheelwright suggests that contemporary terms are privileged against their predecessors in a relation of rational ("making sense") to irrational (foolish, "playing with fancies").
A curious kind of tension emerges between these two points. Wheelwright appears to be saying two different things about the limits of knowledge and, specifically, the types of questions or investigations into knowledge we can attempt. On the one hand, our discourse is riddled with propositions which we know consciously to be factually invalid and even pre-critical. On the other hand, our critical practice is limited by what appears to be rational, as this rationality relates to contemporary views and technologies against the overturned views and technologies of past (and often present) societies and cultures. What then is the place (or time) of discourse in this push and pull against another discourse ("another source")?
Perhaps our knowledge spins in a sort of equipoise, rather than the absolute up-down relationship of critical progress against a pre-critical past. These other sources of knowledge aren't merely the shadow of our current enlightenment. Instead, what we know appears to balance in an acceptance/resistance of what we reject as knowledge proper. Such an Anaximanderian re-evaluation of perspective could prove just as relevant to contemporary questions of social episteme as it did to the questions of astrology which preoccupied that philosopher's time.