Are organisms substances or processes?

I argue that attempts in the philosophy of biology to show that organisms are processes, rather than substances, fail. Despite what process ontologists have said, substance ontology is perfectly able to accommodate the dynamic nature of organisms, their ecological dependence, and their vague boundaries, and their criticisms are directed not at substance ontology simpliciter, but only at specific (perhaps untenable) characterisations of substances. The paper ends by considering what a processual philosophy of biology that is radically in conflict with an ontology of substances might look like.