  Philosophers have sometimes argued that one of these fields is “first philosophy”, the most fundamental discipline, on which all philosophy or all knowledge or wisdom rests. Historically (it may be argued), Socrates and Plato put ethics first, then Aristotle put metaphysics or ontology first, then Descartes put epistemology first, then Russell put logic first, and then Husserl (in his later transcendental phase) put phenomenology first.