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Cudworth, Ralph (1617–1688)


Ralph Cudworth was one of the leading figures among the Cambridge Platonists, a group of seventeenth-century philosopher theologians. He was born in Aller, Somerset, to a minister who had been a fellow of Emmanuel College, Cambridge. Educated at home by his stepfather, John Stoughton, until 1632, he then entered Emmanuel College. There he was influenced by Benjamin Whichcote, founder of the Cambridge Platonist school. In 1639 he was elected a fellow of Emmanuel, and received the bachelor of divinity degree in 1645, defending for his examination Whichcote's thesis that good and evil are eternal and immutable. This examination, with its opposition to any system that makes morality contingent on will, whether human or divine, already betrays Cudworth's distance from the rigorous Calvinism with which Emmanuel College had always been associated. Nevertheless, Cudworth did have some sympathy with political aspects of the Puritan cause. He was appointed by Parliament master of Clare College and Regius professor of Hebrew in 1645, and served as advisor to Oliver Cromwell's secretary of state on several government appointments. In 1647 he was invited to preach to a sharply divided House of Commons.

In his sermon of March 31, 1647, Cudworth urged parliamentarians not to legislate on doctrinal matters, arguing that salvation depends not on speculative details but on living a life of Christlike love and forbearance. This emphasis on morality over doctrine was characteristic of the Cambridge Platonists and influential for the later Latitudinarian divines. Cudworth was appointed master of Christ's College in 1654, and succeeded in retaining his appointment at the time of the Restoration. He remained in the post until his death in 1688. In 1654 Cudworth was married. None of his sons survived him, but his daughter, Damaris, later Lady Masham (16581708), took custody of her father's writings and became a philosopher in her own right. Intimate friend and correspondent of John Locke, she published A Discourse concerning the Love of God in 1696.


Cudworth's massive True Intellectual System of the Universe (1678) was the only one of Cudworth's principal writings to be published during his lifetime. Lengthy as it is, the published volume represents only the first installment of a three-part project originally sketched by Cudworth, with the parts devoted respectively to attacking mechanistic or atomistic determinism, theological determinism (Calvinism), and Stoic determinism. The True Intellectual System of the Universe in its published form constitutes a defense of theistic atomism and an attack on "Hylopathic" atheism. Hylopathic atheism, which claims that all things can be explained by reference to material atoms, with no need to invoke spirit or incorporeal substance, was an important target because it was represented in Cudworth's own day by Thomas Hobbes. A secondary target of the book is "Hylozoic" atheism, differing from Hylopathic in attributing life to matter, but still materialistic, and worthy of Cudworth's notice because of its recent revival by Benedict Spinoza. Rather than engage directly with Hobbes or Spinoza, Cudworth's argument is directed against ancient schools of philosophy, and much of it consists in a consensus gentium argument; atheism is an anomaly or aberration from an original truth that has been acknowledged from the beginning. This original true system accepted atomism, but only as an account of matter or corporeal reality. Properly understood, atomism reveals matter to be essentially passive or inert, thus making clear that only the existence of incorporeal substance can explain the origin, motion, and organization of matter.

While interested in the ancient theology argument that Plato's insights (particularly what Cudworth regarded as a concept of the Trinity in Plato) derived originally from divine revelation through Moses, Cudworth was finally content to claim that there is a natural prolepsis or anticipation of the idea of God existing throughout all times and places. Atheism is thus a willful destruction of this prolepsis, and Hobbes and Spinoza are not new threats, but reincarnations of old foes. The other leading philosophical thinker among the Cambridge Platonists, Henry More (16141687), devoted more direct attention to Spinoza's thought than did Cudworth, and differed from Cudworth as well in seeking, along with Joseph Glanvill (16361680), empirical evidence for the existence of incorporeal substances in cases of witchcraft and demonic possession.

In embracing atomism, Cudworth was making common cause with Cartesian dualism and rejecting scholastic accounts of substantial forms. Mind cannot be simply a property of material objects. For Cudworth, though, it is passivity, not extension, that essentially constitutes matter, and it is activity, rather than self-consciousness, that essentially constitutes incorporeal substance. The key challenge facing Cartesian dualism was to account for the interaction between body and soul, corporeal and incorporeal substance. Cudworth's solution was to appeal to active incorporeal powers that mediate between wholly passive matter and self-conscious soul, creating a vital union between them. Each finite soul has a finite field of actionits own body.

An analogous solution allows Cudworth to articulate the relationship between God and the world. While God is not bound to physical creation as a finite soul is bound to its body, Plastic Nature does serve as an intermediary between God and world that, like the lower powers of the soul, allows for a vital connection between the two. Critical of Descartes's suggestion that the existing ordered universe could have originated from a single initiating divine act, Cudworth argued that an ongoing divine influence was necessary if the material universe was to maintain an ordered motion. At the same time, God is not required, as in occasionalism, to attend directly to each and every detail of order in the universe. Plastic Nature, an unconscious power that pursues not its own but divine purposes, imposes order and finality on the material world. Nothing works according to mere chance, but according to final causes, divine intentions mediated by Plastic Nature.

Cudworth's Plastic Nature is similar to More's Hylarchic Principle, but Cudworth did not follow More's contentions that both material and immaterial substance are extended and that space is infinite. The concept of Plastic Nature was influential for biologist John Ray and for philosophical biology generally up through Darwin. Pierre Bayle attacked Cudworth's plastic powers as atheistic in tendency in eliminating the need for direct divine action to account for purpose displayed in the physical world. Denis Diderot and Jean d'Alembert's Encyclopédie (17511772) included a detailed account of Cudworth's theory, and the theory may, via Paul Janet, have influenced modern doctrines of the unconscious.

On the one hand, Cudworth cannot be finally understood as opposing the new philosophies of Hobbes and Spinoza merely on the basis of allegiance to an outmoded neoplatonism; his consensus gentium argument advances at the same time a contemporary position. On the other hand, the baroque erudition displayed in the True Intellectual System of the Universe was out of step with the leaner philosophical style of his contemporaries. This did not prevent the work from achieving significant influence in its own day, and in fact the text served for several generations as a key resource on Greek philosophy. But it did in the nineteenth and twentieth centuries often mean that Cudworth's importance as an interlocutor of Hobbes, Spinoza, and Descartes was not fully appreciated.


Cudworth's Platonist epistemology is developed at length in A Treatise of Eternal and Immutable Morality. The Treatise was published in 1731 at the behest of Cudworth's grandson, Lady Masham's son. Cudworth argues against empiricism that knowledge is more than a mirroring or representation of reality, and that the mind is more than a blank sheet of paper upon which the objects of sense are inscribed. Knowledge can never arise solely out of sense experience. When we sense, we sense particulars, but when we know, we know by means of universals. Cudworth insists that universals must precede the empirical particulars that they organize and make sense of; they are not abstracted from particulars, for this act of abstraction would be unmotivated and undirected unless one already knew the universal at which one was aiming. Sense allows the soul to perceive the appearances of things, but not clearly to comprehend them.

The universals of which we have knowledge are eternal and immutable. But the fragmented nature of human nature points beyond itself to God. Given the eternal and immutable nature of intelligible ideas, they cannot solely be modifications of limited and finite intellects, which only come to know them in time, if at all. It is God's infinite and eternal mind that, in perceiving itself, eternally perceives these ideas. Rather than innate ideas, human souls possess innate activities or tendencies, a capacity to exert themselves so as to participate in a limited way in divine self-knowledge. Human persons do not, though, arrive at knowledge by comparing their ideas with ideas in the mind of God. Pointing out the impossibility of such a comparison, Cudworth insists simply on clear intelligibility as the criterion of truth. Descartes, Cudworth argues, fell into circularity in seeking further to defend the criteria of clarity and distinctness by proving that God is not a deceiver. The criterion of clear intelligibility is self-evident and depends on no external support.


As the title of A Treatise suggests, among the eternal and immutable ideas that may be known as clearly intelligible are moral principles. In fact, Cudworth's epistemological discussion is occasioned and motivated by his concern to defeat voluntarist and relativist accounts of morality. This concern reached back to Whichcote, but Cudworth was both much more learned than Whichcote about ancient and more recent Platonism and much more connected to contemporary philosophical discourse. As in the True Intellectual System of the Universe, one of Cudworth's key targets is Hobbes, who argues that right and wrong are relative concepts, based solely in convention. Cudworth also attacks "diverse modern theologers" who argue that morality is created by divine fiat, naming among them William of Ockham and Pierre d'Ailly and one contemporary theologian, the Polish Jan Szydlowski. The Calvinistic theology of Cudworth's Puritan contemporaries is a looming unnamed target. Descartes's argument that the natures and essences of things, including moral good and evil, must depend on the contingent will of God in order not to be independent of God, receives particular criticism. Following Plato's Euthyphro, Cudworth argues that things are not good because they are willed by God; rather, God wills things because they are good. It is either eternally true or eternally false that something is good; no act of will can change this. The good is not, though, an external constraint on divine freedom, but God's essential nature.

If the True Intellectual System of the Universe was originally intended as a comprehensive critique of all forms of determinism, Cudworth's many manuscripts defending "freewill" represent his efforts to articulate a positive account of free human action and a moral psychology to accompany that. None of these manuscript treatises were published during Cudworth's lifetime, and it is unclear how widely they may have circulated. Lady Masham may well have shared them with Locke and Shaftesbury. The shortest of the manuscripts was published in 1838 as A Treatise of Freewill, testifying to ongoing interest in Cudworth's thought. In an innovative move, Cudworth rejects traditional faculty psychology; the will and understanding are not distinct faculties in the soul, but activities of the soul. Drawing on Stoic terminology, Cudworth argues that the soul's hegemonikon or ruling power "is the soul as comprehending itself, all its concerns and interests, its abilities and capacities, and holding itself, as it were in its own hand, as it were redoubled upon itself" (p. 178). It is through this reflexive capacity that the soul is able to adjudicate among conflicting passions, dictates of conscience, and inferences of reason, and act as a unified self. Cudworth considers that in identifying this capacity for reflexive deliberation he has successfully shown that persons are not determined by any "antecedent necessary causes" (p. 179). It is far from clear that this is so, although Cudworth's account of the hegemonikon does make it possible to speak intelligibly of the soul's self-determination and moral responsibility.

For Cudworth, moral agency and thus moral responsibility rest on the capacity to survey in a comprehensive way possible courses of action and to pass judgment on which is best. Only action that issues from such reflection can properly be regarded as one's own. God neither has nor needs a hegemonikon, being simple and unified. God's freedom consists in unfailingly acting according to God's own perfect nature, and God's self-determination in the fact that nothing outside of God determines divine action. Insofar as human self-determination takes the form of an active pursuit of the good, human persons come to participate increasingly fully in God and God's goodness. Thus human "freewill" can be employed in order to arrive at a more perfect, more godlike, freedom.

See also Cambridge Platonists; Epistemology; Ethics; Metaphysics.


works by cudworth

The True Intellectual System of the Universe. Stuttgart-Bad Cannstatt, Germany: Friedrich Fromann Verlag, 1964. Facsimile of 1678 edition.

"A Sermon Preached Before the House of Commons." In The Cambridge Platonists, edited by C. A. Patrides. Cambridge, MA: Harvard University Press, 1970.

A Treatise concerning Eternal and Immutable Morality, with A Treatise of Freewill. Edited by Sarah Hutton. Cambridge, U.K.: Cambridge University Press, 1996.

works about cudworth

Darwall, Stephen. "Cudworth: Obligation and Self-Determining Moral Agency." In The British Moralists and the Internal Ought, 16401740. Cambridge, U.K.: Cambridge University Press, 1992.

Hutton, Sarah. "Ralph Cudworth, God, Mind and Nature." In Religion, Reason and Nature in Early Modern Europe, edited by Robert Crocker. Dordrecht, Netherlands: Kluwer, 2001.

Passmore, J. A. Ralph Cudworth: An Introduction. Cambridge, U.K.: Cambridge University Press, 1951.

Scott, D. "Platonic Recollection and Cambridge Platonism." Hermathena 149 (1990): 7397.

Thiel, Udo. "Cudworth and Seventeenth-Century Theories of Consciousness." In The Uses of Antiquity: The Scientific Revolution and the Classical Tradition, edited by Stephen Gaukroger. Dordrecht, Netherlands: Kluwer, 1991.

Jennifer A. Herdt (2005)

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