ABSTRACTAristotle submits to Parmenides’ criterion of simplicity and he tries to cope with the phenomena of complexity by grading ontological status. He lowers the ontological status of accidents because of their dependence using another of Parmenides’ criteria, namely that of independence. Later Aristotle introduced potentiality to keep a simple substance by allowing for implicit complexity. He also prevented first matter from disturbing the simplicity of substance by denying it any ontological status. In the fourteenth century a really simple substance was (...) achieved by Occam by transferring all accidents and even the essence as concepts into the mind. That was a specious solution of the problem of complexity. Epistemology cannot solve ontological problems. The more satisfactory alternative is to admit explicit complexes. Parmenides’ argument against complexity is not sound. One can credit Meinong for being the first to make that move. My own ontology has explicit complexes, namely facts. (shrink)