One category of arguments for dualism is constituted by the standard objections against physicalism. Prime examples are those based on the existence of qualia, the most important of which is the so-called ‘knowledge argument’. Because this argument has its own entry (see the entry qualia: the knowledge argument), I shall deal relatively briefly with it here. One should bear in mind, however, that all arguments against physicalism are also arguments for the irreducible and hence immaterial nat