Donald Mackinnon’s The Problem of Metaphysics (Cambridge University Press, 1974), which is the revised version of his Gifford lectures delivered at the University of Edinburgh in the springs of 1965 and 1966, might be suspected by its readers to be deceptively titled. Though beginning with an overview of Kant’s and Aristotle’s ‘descriptive metaphysics’ (as opposed to ‘revisionary’–Mackinnon takes the distinction from P.F.