 Suppose Lisa burns herself on the hot stove. One of the causal transactions that then follow can be described thus: Lisa removed her hand from the stove because she felt pain. This is a description which seems to pick out ‘being in pain’ as one causally relevant property of the cause. That ‘being in pain’ is a causally relevant property accords well with our intuitions. However, to say it is leads to trouble. The reason for this is that mental properties, like that of ‘being in pain’, can be realized by physically very different systems. Therefore, mental properties cannot be identified with physical ones. On the other hand, we seem to live in a physically closed and causally non-overdetermined universe. But this means that, contrary to what we have supposed so far, Lisa did not remove her hand because she felt pain. In general, it means that mental properties are not causally relevant, however much they seem to be (cf. Kim 1989 for a famous expression of this problem).