Abstract

The present study examines the concept of epistemic justification, with particular reference to establishing conditions under which this concept can be applied to computer reasoning systems: what is it, we ask, to say of a computer that it has arrived at an unjustified conclusion--that it has reasoned as it ought not to have reasoned? This problem is important because of its relevance to the relation between the two conceptual schemes of mind, thought and reasoning on the one hand, and of computers, programs and computation on the other. Chapter 1 discusses the apparent immiscibility of these two conceptual schemes and how epistemological concepts figure in the relation between them. ;We make a fundamental distinction between two ways in which a reasoner can reason as he ought not: first, by accepting bad principles of reasoning, and second, by inferring something which his beliefs and principles do not license. Chapter 2 attacks the problem of making sense of this second possibility: in what way can a reasoner's beliefs and reasoning principles determine something to be inferable in a way which is partially independent of his inferential dispositions? Chapter 3 goes on to argue that certain kinds of reasoners--those capable of 'default' reasoning--must themselves possess epistemological concepts in order to articulate the principles of reasoning they accept. The outcome of this discussion is an account of beliefs about the justifiedness of one's own putative inferences. The final chapter extends this account to beliefs about the justifiedness of others' inferences. ;The main findings are: Certain epistemological concepts find natural application to some types of computer reasoning systems. Such reasoning systems will themselves require these concepts to articulate the principles of reasoning they accept. Judgements involving the concept of epistemic justification can be explained in terms of the concepts thus identified. The present account of justification has a noncognitivist flavor: we give a theory of what it is to have certain beliefs involving the concept of epistemic justification by saying how such beliefs function; we remain silent as to what, if anything, those beliefs are about