Author: Bruce Long

Discipline: Philosophy

Subdiscipline: Epistemology (The study of what knowledge is and how we get it)

Categories/Topics: Epistemology, Reliabilism, Informational Epistemology, Justified True Belief, The Gettier Problem

Philosopher(s):  Fred Dretske, Edmund Gettier, Alvin Goldman, Plato

Relevant Work: (Refer to Amazon recommended reading at bottom of article.)

Epistemology, or the study of knowledge and the nature of knowledge, is a long standing discipline in philosophy. Knowledge is most often – or historically has been most often – associated with true beliefs defined in some way. More contemporary theories of knowledge focus on the role of causality and causal chains and reliable mechanisms of updating internal belief states (internal mental states or content ‘in the head’ that is taken to constitute beliefs) and/or informational dynamics (the possession and updating of information with reference to mathematical and quantitative theories of information.)

Alvin Goldman

Fred Dretske

All cognitive agents – including many animals – can be ascribed beliefs where belief is the state of giving cognitive or mental assent to some piece of information as true or as corresponding to material facts in the world. What is in dispute according to cognitive scientists and epistemologists (philosophers interested in theories of knowledge) is the content of the beliefs and how they come to be established, and the degree to which they accurately capture information from the external world. To make matters more complicated, the nature of belief itself is also debated.

Some epistemologists think that the Platonic (originating with Plato) conception of knowledge as justified true belief (JTB) is correct. This conception fell into disrepute with a 1963 paper by Edmund Gettier (Is Justified True Belief Knowledge?) which presented what is now referred to as the Gettier problem. Very briefly, this is the idea that justification can fail, and thus there are exceptions to the JTB view that mean it cannot be the right conception of knowledge or what it is to have knowledge.

More recently in history (notably with the 1981 work by American philosopher of information Fred Dretske – Knowledge and the Flow of Information) and with the work of reliabilist epistemologist Alvin Goldman, knowledge has come to be associated with the causally sustained correlation of mental states with sources of information. That is to say – the content of knowledge has to be caused by something that is able to cause updates to internal mental representations or mental content of other kinds (on a reliable basis where reliability has something to do with the mechanisms of updating the internall content being governed by natural laws and reliable systems of perception and cognition.)

The struggle to acertain a concrete and correct conception and definition of knowledge and a theory of knowledge and of what constitutes real epistemic content (information in the head that results in knowledge) continues with both philosophers of mind and cognitive scientists. There has been a recent revival of the idea of JTB with flaws in Gettier’s argument and the basis of The Gettier Problem suggested.

Other philosophers think of knowledge as determined and established partly or even chiefly externally – by social standards and norms. This kind of view is referred to as externalism about epistemic content.


1. Gettier, E., (1963). Is justified True Belief Knowledge?
2. Goldman, A., (1967). A Causal Theory of Knowing, Journal of Philosophy 64: 357-372.

Recommended Reading (Intermediate)

Recommended Reading (Advanced)