Edmund Lee Gettier III (/ˈɡɛtiər/; October 31, 1927 – March 23, 2021) was an American philosopher at the University of Massachusetts Amherst.

He earned his PhD in philosophy from Cornell University in 1961 with a dissertation on “Bertrand Russell’s Theories of Belief” written under the supervision of Norman Malcolm.

"[6] While at Pittsburgh, he met a young Bas C. Van Fraasen[7] and published his first and only book review of John Passmore's Philosophical Reasoning.

[4] Gettier's fame rests on a three-page article, published in Analysis in 1963, that remains one of the most famous in recent philosophical history.

In it, Gettier challenges the definition of knowledge as "justified true belief" that dates back to Plato's Theaetetus but is discounted at the end of that very dialogue.

This account was accepted by most philosophers at the time, most prominently the epistemologist Clarence Irving Lewis and his student Roderick Chisholm.

Major responses include: A 2001 study by Weinberg, Nichols, and Stich suggests that the effect of the Gettier problem varies by culture.