John Griggs Thompson

John Griggs Thompson (born 1932) is an American mathematician who, with Walter Feit, proved the Feit-Thompson theorem in 1963. He received the Fields Medal in 1970 and the Abel Prize in 2008 for his profound contributions to the theory of finite groups.

Thompson's work on the Feit-Thompson theorem and the subsequent classification of finite simple groups transformed group theory from a subject of isolated theorems into a systematic discipline with a complete inventory of its basic objects. His influence extends through a generation of students who carried the structural revolution he initiated into every branch of mathematics.

Thompson did not just prove theorems. He proved that theorems could be proved at a scale that no single mind could contain. The Feit-Thompson proof was 255 pages. The classification was 15,000. Thompson stood at the transition point between the two eras — the last great solitary prover and the first great collaborative one.