Abstract
Theories of emergent properties are build around the idea that, once material composites have reached some level of complexity, causal powers arise that cannot be reduced to the powers of the constituents. This idea can be traced back to ancient Aristotelian and Galenic views, but seems to be absent from early modern natural philosophy. The present article argues that emergentist intuitions play a role in the discussion of nutrition in the early seventeenthcentury commentary on the Hippocratic Aphorismi by Antonio Ponce de Santacruz, royal physician to the Spanish king Philip IV. Santacruz understands the new causal powers of the substantial forms that arise from nutrition in close analogy with the new causal powers that he ascribes to the substantial forms of mixtures and the substantial forms of elements. Thereby, he complements a theory of material upward causation through a theory of formal downward causation - a kind of causation that modifies the material basis from which new causal powers have emerged. As Santacruz conjectures, these new causal powers involve emanative causation - the type of causation that brings about an effect without undergoing a change in the cause.