What Is Knowledge? Justified True Belief and the Gettier Problem

Epistemology is the branch of philosophy that studies knowledge: what it is, how we get it, and how much of it we can have. Before we can ask whether we know anything about the external world, other minds, or the past, we need a working account of what knowledge actually is. The most influential starting point in Western philosophy is the tripartite definition, often traced back to Plato's dialogue Theaetetus, where Socrates and his young interlocutor probe the idea that knowledge is something more than mere true opinion.

The tripartite definition

According to the tripartite analysis, a person S knows that a proposition p is true if and only if three conditions are met. First, p must be true. You cannot know something false; if you sincerely claim to know that the earth is flat, you are mi