My challenge is to explain how we think with our bodies and the things around us, how it can be literally true that there are times when dancers use their bodies as things to think with, or that students of physics can handle a cup of tea and, in that handling, co-opt the cup to help think about surface tension, suspensions, or gravity. The most effective interactive design enables people to couple so closely and seamlessly with things that they behave as one. I will use data from an extensive ethnographic study of a world-class choreographer at work, and also report on a few simple experiments to show that indeed there is such a thing as enactive thought.