who from 1836 held the chair of logic and metaphysics at Edinburgh. He held the view that perception gives us a direct or immediate relation with its objects, although one that is in Kantian vein ‘conditioned’ by the medium and the nature of the knowing subject. Of ultimate or unconditioned reality we can know nothing. Like Kant, Hamilton applies this result to show our inability to know the nature of space and time. In logic, Hamilton was famous for the doctrine of the ‘quantification of the predicate’, the subject of acrimonious dispute with De Morgan. His principal work is the four-volume Lectures on Metaphysics and Logic (1859–60). One of J. S. Mill’s major works is the Examination of Sir William Hamilton’s Philosophy (1865).