AbstractWe propose an account of cognitive tools that takes into account the process of enculturation by which tools are integrated into our cognitive systems. Drawing on work in cultural evolution and developmental psychology, we argue that cognitive tools are complex entities consisting of physical objects, representational systems, and cognitive practices for the physical manipulation of the tool. We use an extensive case study of spatial navigation to demonstrate the core claims. The account we provide is contrasted with conceptions of cognitive tools that simplify cognition, in particular that they offload cognitive work, or that the tools themselves are temporary developmental scaffolds or props. Enculturation results in transformed cognitive systems, and we can now think and act in new ways with cognitive tools.