Studies of mind, thought, and reason have tended to marginalize the role of bodily form, real-world action, and environmental backdrop. In recent years, both in philosophy and cognitive science, this tendency has been identified and, increasingly, resisted. The result is a plethora of work on what has become known as embodied, situated, distributed, and even ‘extended’ cognition. Work in this new, loosely-knit field depicts thought and reason as in some way inextricably tied to the details of our gross bodily form, our habits of action and intervention, and the enabling web of social, cultural, and technological scaffolding in which we live, move, learn, and think. But exactly what kind of link is at issue? And what difference might such a link or links make to our best philosophical, psychological, and computational models of thought and reason? These are among the large unsolved problems in this increasingly popular field. This book offers both a tour of the emerging landscape, and an argument in favour of one approach to the key issues. That approach combines the use of representational, computational, and information-theoretic tools with an appreciation of the importance of context, timing, biomechanics, and dynamics. More controversially, it depicts some coalitions of biological and non-biological resources as the extended cognitive circuitry of individual minds.