Philosophers use the word ‘grounding’ to refer to the kind of non-causal explanatory relationship that holds, for example, between the fact that there is a party at Bill’s house and the fact that Bill and his friends are dancing, drinking etc. The revelling of Bill and his pals do not cause a party to come into being, in the way the magical dancing of wizards may cause a spirit to come into existence. The relationship is more intimate than that: the fact that there is a party wholly consists in the fact that certain people are dancing, drinking, etc. Likewise, according to constitutive panpsychism, the fact that I am conscious wholly consists in the fact that certain particles in my brain are arranged in, or interacting in, a certain way (see the entry on metaphysical grounding for more discussion of the grounding relation). This is the form of panpsychism that suffers most acutely from the combination problem, which we will explore below. However, if it can be made sense of, constitutive micropsychism promises an elegant and parsimonious view of nature, with all the richness of nature accounted for in terms of facts at the micro-level. Luke Roelofs (2019) has developed a particularly detailed form of constitutive micropsychism.