 What are these phenomena? In Metaphysical Disputations XV, Suárez appeals most forcefully to the following four: first, we find accidents unified in a single subject (DM XV 1.7); second, as a related matter, we observe various properties in a single subject, both essential and accidental, standing in superordination and subordination relations to one another (DM XV 1.14); third, we experience various entities coming into and going out of existence, suffering, in his preferred idiom, generation and corruption (DM XV 1.7); and finally, we observe various physical systems, including especially (but not only) living beings manifesting equilibrium states which they maintain unless put under pressure, and to which they return when a pressure applied has been relieved (DM XV 1.8).