 This denial of substantiality to bodies gives rise to an important interpretive issue. The traditional concept of a substance has at least two important strands. One is the idea we have already seen, of substance as independent. Spinoza clearly means his ‘demotion’ of bodies to modal status to be a denial that they are substances in this sense. But another is the idea of a substance as an ultimate subject of predication, that is, as something of which properties or relations may be predicated, but which is itself never predicated of anything else. Does Spinoza mean to deny to bodies and other finite things this status as an ultimate subject as well? That is, is talk of bodies fundamentally to be construed for Spinoza as predicative or adjectival on substance? Or do bodies, though they are not substances, nonetheless lie on the subject side of the subject/predicate divide, themselves bearers of properties, but not strictly properties of anything else? This matter is of the utmost importance for the understanding of Spinoza's physical theory, since deciding that Spinoza held bodies to be in fact ways substance is and adjectival on it, in accord with the former interpretation, requires that bodies as ordinarily conceived must be thought of as arising from and reducible to some more fundamental qualitative variation in spatiotemporal regions of extension. This has the consequence, to some commentators salutary, of rendering Spinoza physical theory strongly prescient of contemporary physical views, in which ultimately physical nature is conceived as a field of gradient forces, bodies being not ultimate, but rather the consequences of particular local concentrations of certain classes of those forces, yielding certain characteristic effects in interactions, which effects we take as marking the presence of bodies.