This paper examines the application of the mutual manipulability criterion as a way to demarcate constituents of cognitive systems from resources having a mere causal influence on cognitive systems. In particular, it is argued that on at least one interpretation of the mutual manipulability criterion, the criterion is inadequate because the criterion is conceptualized as identifying synchronic dependence between higher and lower ‘levels’ in mechanisms. It is argued that there is a second articulation of the mutual manipulability criterion available, and that it should be preferred for at least two reasons. The first is that the criterion of mutual manipulability is an instance of continuous reciprocal causation. The second is that it has implications for how to understand this distinction between causation and constitution. It is shown that when considering dynamic systems, continuous reciprocal causation - ubiquitous in dynamical systems - is a form of constitutive causality, which entails that causal factors may, in the right circumstances, by genuine constitutive factors of cognition. This notion of constitutive causality lends support to conceiving of the mutual manipulability criterion as a genuine demarcation principle in the debate over the boundaries of mind.