Can we understand other minds ‘from the inside’? What would this mean? There is an attraction which many have felt in the idea that creatures with minds, people (and perhaps animals), invite a kind of understanding which inanimate objects such as rocks, plants and machines, do not invite and that it is appropriate to seek to understand them ‘from the inside’. What I hope to do in this paper is to introduce and defend one version of the so-called ‘simulation’ approach to our grasp and use of psychological concepts, a version which gives central importance to the idea of shared rationality, and in so doing to tease out and defend one strand in the complex of ideas which finds expression in this mysterious phrase.

Let us here recap the salient ideas of the simulation approach. Simulationism is to be contrasted with another approach to philosophy of mind which has, at least among Anglo-American analytic philosophers, been the dominant one of the last decades and which has also been an important influence on psychologists and cognitive scientists. We may call this familiar alternative the theory theory. The version best known to philosophers is functionalism in philosophy of mind. This says that to grasp psychological notions is to grasp that there are certain inner states of persons which are typically caused by such and such external events, which interact among themselves to cause further inner states and events, and which finally combine to cause behaviour.