Abstract

According to Russellian monism (RM), the quiddities which underlie the fundamental causal structure of the physical world are also responsible for the existence of phenomenal consciousness. This view has been argued to provide an attractive alternative to physicalism and dualism, but it is plagued by the so-called ‘combination problem’ – namely, the problem of explaining how the quiddities underlying the microphysical structure of a macroscopic conscious agent (e.g., a human being) combine together to constitute his or her phenomenal experiences. In this paper, I will explore a type of monism that avoids the combination problem altogether. According to this view – which I shall call panquidditist monism – all causal roles, and not just the fundamental ones, stand in need of quiddities realizing them. Moreover, the quiddities that realize causal roles at one physical level should not in general be seen as grounded in, or otherwise derivative on, the quiddities that realize causal roles at lower levels. Crucial to the tenability of this view is a distinction between two varieties of grounding – one aiming to metaphysically explain the causal properties of various objects ‘from below’ (vertical grounding), the other aiming to metaphysically explaining them ‘from the inside’ (horizontal grounding). I will argue that, thanks to the distinction between vertical and horizontal grounds, panquidditist monism is well-placed to secure the advantages that RM promises – but, because of the combination problem, fails to deliver – vis-à-vis physicalism and dualism.