People use the word “know” all the time, but what does it mean? Most of us feel that we have an intuitive grasp of the concept, but providing a more rigorous analysis of it is difficult.

Types of Knowledge

Philosophers typically divide knowledge into three types: personal knowledge, procedural knowledge, and propositional knowledge. The primary concern of epistemology is propositional knowledge, but contrasting this with other types of knowledge can help in clarifying precisely what it is that epistemologists are discussing.

Theories of Knowledge

The most popular account of knowledge is the tripartite theory. This theory, which analyses knowledge as justified true belief, is widely used as a working model, even though most philosophers recognise that it has serious difficulties.

The closest thing to a rival to the tripartite theory is infallibilism, which suggests that knowledge requires absolute certainty, as opposed to belief or opinion about which there is more doubt.