A History of Philosophy, Vol. IV: Descartes to Leibniz

Summary

Descartes to Leibniz (1958) is the fourth volume of Frederick Copleston's A History of Philosophy and the first of three he devoted to the seventeenth and eighteenth centuries. Volume V would take the British philosophers from Hobbes to Hume and Volume VI the French and German Enlightenment through Kant, so this book carries an unusually long introduction meant to serve all three. That introduction asks what changed when philosophy became 'modern'. Copleston acknowledges the break that Descartes announced, but he also points to continuities with late scholasticism and the Renaissance, and to the immense prestige of mathematical physics after Galileo. He explains the familiar division of the period into continental rationalists and British empiricists, then qualifies it: the labels mark tendencies, not sealed camps, and the rationalists themselves valued experiment and observation. Descartes receives the fullest treatment. Copleston follows the rules of method in the Discourse, the systematic doubt and the cogito of the Meditations, the proofs of God from the idea of the infinite and from the idea of a perfect being, God's role in guaranteeing clear and distinct ideas, the real distinction of mind and body, and the mechanical physics of extended matter. He notes the difficulties Descartes's contemporaries raised, including the charge of circular reasoning and the puzzle of how an unextended mind can move an extended body. Pascal stands apart as a mathematician who refused to make geometry the model of all knowledge. Copleston presents his contrast between the geometrical mind and the intuitive mind, the reasons of the heart, the wager and the portrait of human greatness and misery as the work of an apologist rather than a system-builder. The Cartesian movement and the occasionalists, among them Geulincx and above all Malebranche, follow, with Malebranche's teaching that God is the only true cause and that we see all things in God. Spinoza is expounded through the geometrical order of the Ethics: one infinite substance, God or Nature, known to us under the attributes of thought and extension; the necessity of all that happens; the analysis of the passions; the three kinds of knowledge; and the intellectual love of God. Copleston adds Spinoza's political writings and weighs the old dispute over whether his system is pantheism, atheism or something harder to name. The volume ends with Leibniz, whose monads, pre-established harmony, principle of sufficient reason and defence of this as the best possible world are read in close connection with his logic. Copleston repeatedly measures each system by how it relates God, the mind and the physical world, and he observes how far all of them still depend on the scholastic vocabulary of substance and cause even while transforming it. The book remains in copyright, so this library offers a description and buying links rather than its text.

Top Lessons

• Doubt as a tool, not a home

  Copleston shows that Descartes doubted methodically in order to reach certainty, not to rest in scepticism, and that the method's success depends on whether the proofs of God hold. Students learn the difference between disciplined questioning and corrosive suspicion, and why a starting point inside the self raises the problem of reaching the world again.

• The heart has its reasons

  In Copleston's account Pascal accepts mathematical rigour in its own sphere yet denies that it can settle the questions that matter most. Knowledge of first principles, of persons and of God comes through what he calls the heart, a kind of intuitive grasp rather than mere feeling. The chapter teaches students to recognize different kinds of evidence suited to different subjects.

• Who really causes things?

  Occasionalism, in Geulincx and Malebranche, arose from a serious problem in Descartes: if mind and matter share nothing, how can either act on the other? Their answer, that God alone acts and creatures only supply occasions, shows how a solution to one puzzle can unsettle ordinary beliefs about responsibility and nature.

• Freedom as understanding necessity

  Spinoza denies free will in the ordinary sense and locates human freedom in understanding the necessity of things and loving God intellectually. Copleston expounds this with care before noting how sharply it departs from Christian teaching on creation and personal choice. Students can practise stating a view accurately before saying where and why they disagree.

• Is this the best possible world?

  Leibniz argued from God's wisdom and goodness that the actual world, evil included, is the best of the possible worlds. Copleston places this inside Leibniz's logic of sufficient reason and his account of compossible things. The doctrine invites students to think about providence and suffering with more precision than slogans allow.

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Medical Lens

The volume is a standard map of the seventeenth-century debates from which modern talk of mind and brain descends. Descartes's mechanical physiology and his account of the passions, Spinoza's treatment of the emotions as confused ideas that understanding can master, and Leibniz's unnoticed 'little perceptions' are each expounded. A reader in psychiatry or the history of medicine can use the relevant chapters as a reliable orientation before turning to the primary texts; Copleston himself writes as a philosopher, not a historian of medicine, and the physiology is background rather than his focus.

• Descartes chapters, on the relation of mind and body

  Copleston's exposition of the real distinction between thinking and extended substance, the interaction of soul and body through the pineal gland and animal spirits, and the difficulties critics raised.

• Spinoza chapters, on the passions and human bondage

  Exposition of Spinoza's analysis of the emotions and his claim that forming a clear idea of a passion lessens its power, an early rational therapy of the affects.

• Leibniz chapters, on perception and apperception

  Account of Leibniz's distinction between perception and conscious apperception and of perceptions too small to be noticed, often cited as an early recognition of unconscious mental life.

• Chapter on Cartesianism and Malebranche

  Occasionalist replies to the problem of mind-body interaction, in which God produces bodily motions on the occasion of volitions and sensations on the occasion of bodily changes.