We have seen that, compared to Spinoza at least, Descartes was very conservative in his metaphysics of mind. He was conservative in other ways, too. His whole effort was to introduce his new framework for a science of nature without incurring political, moral or religious censure, and as a result he says very little about religion, morality or politics – and what he does say is traditional, uncontroversial stuff. Spinoza, again, is much more radical. He wrote a Political Treatise, and a Theologico-Political Treatise. In addition, his master work, the Ethics, is an astonishing feat of miniaturisation which, in a little over 200 densely packed and closely argued pages, presents a moral and political theory based on a naturalistic account of human nature which is itself grounded in a complete metaphysical and epistemological system. Book 1, God, lays out the basics of metaphysics, the structure of reality as a whole. Book 2, The Nature and Origin of the Mind, then explains the place of man within that metaphysical framework, by setting
out the fundamentals of Spinoza’s philosophy of mind and epistemology. In Book 3, The Origin and Nature of the Emotions, he builds on that picture to present a detailed theory of psychology, and then in Books 4 and 5, Human Bondage, or the Power of the Emotions, and Human Freedom, we have an extensive working out of what this new, scientifically based understanding of human beings amounts to in terms of the good life for man, both at the individual and at the social level. It is a truly amazing piece of work: astonishing in its scope and completeness, almost beautiful in the austere, remorseless way it works through the exposition of his passionate vision, and magnificently, naively courageous in the simple, honest radicalism of his views. A pity then that it is such hard going as to be almost unreadable.