Abstract

When we try to think about the causal nexus and the physical nature of the world as a whole we may be struck by two quite different difficulties in finding room in it to accommodate together knowledge or reasoned belief and causal determinism. may seem to us to exclude and may seem to us to exclude. Taking it as a fact that there is knowledge and that knowledge seems to be indefinitely extensible, it has been felt by some philosophers that we can disprove total determinism by showing that if there were laws of nature which purported to govern all movements of matter in the universe there would still be something which even an ‘all-knowing’ predicter could not predict, viz. his own predictions or his own actions; and that given enough knowledge any agent could refute anybody else's predictions of his actions. So it has been thought that the phenomenon of knowledge somehow shows there cannot be laws to govern all movements of matter in the universe. This comfortably anodyne reflection is examined in the second part of the lecture. It elevates human minds and even confers a sort of cosmic importance on them. The other difficulty in making room for both and is in some loose sense the dual of this. Instead of taking knowledge for granted and questioning total determinism, it merely takes causality for granted but then deduces the total impossibility of knowledge. It simply asks: ‘How can we take a belief seriously, or consider it seriously as a candidate to be knowledge, if it is no better than a simple physical effect?’ This is a more pessimistic reflection and I shall begin with it.