Knowledge, Theory of Philosophy 83 History 60 Science 41 Metaphysics 38 Reason 34 Ethics 28 more ... Belief and doubt 27 Causation 26 Cognition 25 Logic 24 Truth 23 Skepticism 21 Philosophy of mind 20 Realism 19 Methodology 18 Language and languages 17 Thought and thinking 17 Empiricism 15 Ontology 15 Perception (Philosophy) 15 Phenomenology 15 Cognition in children 14 Intellect 14 Consciousness 13 Philosophy, Modern 13 Perception 12 Experience 11 Meaning (Philosophy) 10 Psychology 10 less ...