Seeing that the main causal question investigated in the volume concerns children’s explanations of the origins of natural things and of primary matter, Chapter 2 reviews the relevant research and theory on causal development with the aim of highlighting the presence of metaphysical tendencies in children’s causal reasoning. It argues that two causal distinctions are needed for interpreting data from children and adults alike: (1) intrinsic vs. extrinsic causal agents and mechanisms and (2) derived vs. primary origin of natural entities. Developmental research has hitherto focused on children’s understanding of intrinsic or physical causal concepts, i.e., scientific, yet philosophers of science have argued that science too has its own metaphysics and that the two forms of causal understanding – physical and metaphysical – interact when seeking to explain empirical phenomena.