 Jaworski is particularly clear in emphasising that he is a causal pluralist and that the structural level is in no sense epiphenomenal or a mere logical construct out of the lower properties (see his 2011: 174). But one might query whether this is consistent with accepting the possibility of closure under physics. Such closure naturally raises the question of the causal claims made for form or structure, and, hence, for their ontological weight. The importance of explanations at the level of complex structures is not disputed, but whether these represent just ways of conceptualising a fundamental level that we cannot normally access, is another matter. Johnston raises this question (2006: 660–62) but leaves it unresolved. Jaworski insists on causal pluralism, but admits “all forces are operating at a fundamental physical level”: This latter remark seems to concede that what one has in fact is an explanatory pluralism, with causation included in the domain of explanation, but all the brute force is confined to physics. Johnston is keen to deny that explanation is a subjective or psychological phenomenon, but admitting this does not place explanation in the world, in the sense in which the forces that actually make things happen are in the world: it only gives them the Platonic objectivity of propositions or theories. 