A collection of all but two of the author's philosophical essays and lectures originally published or presented before August 1976.

Popper's definition looked initially promising provided that the restriction of classical logic was removed. As we have seen, this promise is not fulfilled. The search for a satisfactory verisimilitude ordering must therefore be pursued along more mainstream lines. The present exercise ought, however, to make us aware of the possibility that breakdowns of proposed definitions might only occur because of strictly classical assumptions.

PART ONE I 'Alternative' in 'Alternative logic There are many systems of logic — many-valued systems and modal systems for instance - which are non-standard ...

In this paper, a survey is made of some of the contributionsto the interpretation of Hartle and Hawking's theory of thewave function of the universe and its beginning. It is arguedthat there are considerable difficulties with the interpretationof the theory, but that there is at least one interpretationhitherto not found in the literature which survives existingphilosophical objections.

Part of an early version of this paper was read at the University of Warwick in October 1977, and a later version was read at the Newcastle Royal Institute of Philosophy in November 1977 and at Aberystwyth and Oxford in early 1978. Thanks are due to the many colleagues and friends who made helpful comments on early drafts; special thanks to Hugh Mellor, Rita Nolan and Paul Weiss for detailed written criticisms, and to Don Locke, for very helpful discussions.