The difference between epistemology and ontology in part is the subject that is being studied by each. In ontology, the study of being or existence and questions of what kinds of entities exist are studied. In epistemology, the study of knowing and how we come to know and questions about what knowledge is and how knowledge is possible are studied.Both ontology and epistemology are branches of philosophy. Ontology is a type of metaphysics. Epistemology often involves a debate between empiricism and rationalism, in which the former claims knowledge can only be gained through experience whereas the latter believes that knowledge can be acquired through reason alone.Ontology concerns itself with what is true, and on the other hand, epistemology involves the different methods of figuring out that truth. Put in other words, ontology is about the nature of reality and epistemology is about the relationship between the researcher or other person and that reality.Many issues have multiple, often conflicting ontologies, or theories about what is true, as well as various epistemologies, or ways of figuring things out. For example, science and religion have oppositional ontologies and epistemologies about the existence of God and the origins of the universe.

Ontology and EpistemologyOntology:The branch of metaphysics (philosophy concerning the overall nature of what things are) is concerned with identifying, in the most general terms, the kinds of things thatactually exist. In other words addressing the question:What is existence? and What is the nature of existence?When we ask deep questions about "what is the nature of the universe?" or "Is there a god?" or "What happens to us when we die?" or "What principles govern the properties of matter?" we are asking inherently ontological questions.Epistemology:The branch of philosophy concerned with the nature of knowledge itself, its possibility, scope, and general basis. More broadly:How do we go about knowing things? or How do we separate true ideas from false ideas? or How do we know what is true?or "How can we be confident when we have located 'truth'?" "What are the systematic ways we can determine when something is good or bad?"So ontology is aboutwhatis true and epistemology then is aboutmethodsof figuring out those truths.The split between Plato and Aristotle is both ontological and epistemic. The split between religion and science is both ontological and epistemic.For example, religion and science offer two very different ontologies (theories about what is out there) and epistemology (ways to figure out what is out there).And the split between Plato and Aristotle matches exactly the split between religion and science...and you should leave this class understanding why and how!