This paper reports on a programme of research carried out over a period of twenty years by Joan Bliss, Jon Ogborn and others, and aimed at understanding how pupils and students reason about the everyday physical world. Our starting point was the science alternative conceptions literature, particularly force and motion, where the results puzzled and motivated us to make sense of the diversity of the findings. In a second step a Commonsense Theory of Motion was developed, which served as a framework for four other studies in the area of force and motion. These revealed that children were indeed using their everyday knowledge to explain these physical notions. The next step was to ask whether children also reasoned in a commonsense way about the physical world more generally, which led to the development of both a new theoretical framework and a further study to investigate these ideas. The findings showed that the physical reasoning schemes shown to exist were: "movement, action/force/effort, container, carrier, support, fall, barrier, resistance, space, flow, break/not break, rigidity, stretch/squash and balance". The last section describes some ideas for future research in this area. (Contains 1 figure and 3 tables.)