Top 10 Philosophical Theories and Concepts Proposed by Philosophers

1 "Cogito, ergo sum" (I think, therefore I am) - Rene Descartes

2 Theory of Forms - Plato

3 Categorical Imperative - Immanuel Kant

4 The Theory of Being and Non-Being - Parmenides

5 Socratic Method - Socrates

6 Four Causes - Aristotle

7 Atomism - Democritus and Leucippus

8 Hume's Causation - David Hume

9 The City of God - St. Augustine

10 Labor Theory of Value - Karl Marx