Definitions of Intelligence

From AGIRI.org

71 Definitions of Intelligence

Conveniently compiled by Shane Legg here

Formal Definitions of Intelligence

The most rigorous definition of intelligence given so far is likely in Shane Legg and Marcus Hutter's paper,

Universal Intelligence: A Definition of Machine Intelligence
Shane Legg and Marcus Hutter. In Minds and Machines, pages 391-444, volume 17, number 4, November 2007.

A closely related but non-identical definition was given in Ben Goertzel's 1993 book The Structure of Intelligence

The utility of formal, mathematical definitions of intelligence is hotly debated within the AGI community.