Naturalist emergentism and causal explanation

The problem of the exclusion of the causal efficacy of mental properties by physical properties has mainly been mainly raised in connection with non reductionist materialism of a functionalist kind. It is therefore legitimate to wonder whether the alternative form of non reductionist materialism that emergentist naturalism often pretends to incarnate can overcome the exclusion problem. And it is first necessary to examine whether the difference that separates the notions of functional and emergentist properties is such that naturalist emergentism does not face the exclusion problem. The article answers negatively to this question by arguing that the exclusion problem is rooted in the notion of an abstract and irreducible property, and that the difference between functional and emergentist properties amounts to one between two species of such an abstract and irreducible property.