ABSTRACT
Part IV will be something of a miscellany compared with previous Parts, treating such disparate topics as space and time, meaning, the imagination and necessity. Yet there is a line of argument which connects them. The main purpose is to examine Locke's answer, and to suggest a different answer, to what is perhaps the most puzzling question in epistemology: the question of the nature of a priori knowledge and necessary truth. To get that far it will be necessary to consider his account of the distinction between particular and universal thoughts, in comparison with other accounts. Since he took it that the latter are distinguished from the former by their abstracting from 'considerations of time and place', it will be convenient to preface discussion of these matters with an examination of his general account of time and space, and our ideas of them. By doing so we may at least avoid the assumption that thinking about particulars is unproblematic, and that only thinking about universals raises any problem.
