Mill’s importance as one of the major figures of nineteenth-century politics and culture, and the current interest in him as a moral and political philosopher, are both so great that they make it hard to see him in another aspect—as a leading contributor to the British tradition of epistemology and metaphysics. Yet it was the System of Logic (1843) that first established his reputation; and his views in this field remain as interesting and relevant as his better known views in ethics and politics.
Throughout his intellectual life Mill sought to weave together the insights of enlightenment and Romanticism. He applied Romantic idealism’s moral understanding to utilitarianism’s concepts of character, imagination and purpose, freedom and reason, human good. To German Romanticism he owes one of his master themes—that of the culture of human nature as a whole, both in its diverse spontaneity and in its rational autonomy. But the metaphysical and psychological foundations of his thought lie securely in the naturalistic empiricism of the British school—and, moreover, in its radical and associationist, rather than its conservative and innatist, wing. Thus the deepest questions about Mill’s philosophical success turn on the possibility of such a synthesis, and on how far he achieved it.
Reasons for doubt centre on two great issues, which at bottom are linked. Must not naturalism subvert reason, as Kant thought? And must not a natural science of man—a scientific psychology—subvert the understanding from within, the moral psychology of autonomy and expressive spontaneity, which Mill shares with the ‘Germano-Coler-