Lady Conway (née Finch) was one of the very few women philosophers of the seventeenth century. She studied Cartesian philosophy with the Cambridge Platonist Henry More, who translated Descartes’ Principles of Philosophy especially for her. Barred from attending university because she was a woman, she studied by correspondence. She was thus exposed to both More's enthusiasm for Descartes and his critique of Cartesianism. She published nothing in her lifetime, but her posthumously published Principia philosophiae antiquissimae et recentissimae (1690) (English trans., The Principles of the Most Ancient and Modern Philosophy, 1692) rejects the Cartesianism of her philosophical education. Notably, she argues that on Descartes’ definition of mind and body it is impossible to account for interaction between them. Furthermore, it is contradictory to suppose that God as a perfect living being, would create a substance so unlike himself as body as conceived by Descartes. These objections lead her to posit a monism of substance, where all things consist of living particles, which she calls monads. She outlines a Neoplatonic hierarchy of being in which all things derive from God by a process of continuous emanation. Her critique of Cartesian dualism is tempered by her acknowledgment of Descartes’ achievement in elucidating the laws of mechanical motion (see law of nature). The work registers the influence of Francis Mercurius Van Helmont, who brought it to the attention of Leibniz.

See also Cartesianism; Dualism; Human Being; More, Henry; Principles of Philosophy

The Cambridge Platonist, More, was one of the most influential figures in the early reception of Cartesianism in England, as both admirer and critic of Descartes. He was one of the first to advocate the teaching of Descartes’ philosophy in English universities and is credited with coining the term “Cartesianism.” More's interest in Cartesian philosophy is first registered in his long poem, Democritus platonissans (1646). In 1648 he entered into correspondence with Descartes (1648–49), possibly at the instigation of Samuel Hartlib. He was attracted by Descartes’ natural philosophy, which he regarded as the best account of the phenomena of nature in the post-Aristotelian context of the mid-seventeenth century. Much as he admired Descartes’ natural philosophy, he did not accept Descartes’ physics in every detail but sought to enlarge the metaphysical dimension of Cartesianism.

In his letters, he argues that that all substance, both corporeal and incorporeal, is extended and that God Himself is res extensa. Since both corporeal and incorporeal substance are extended, the operative distinction between them is solidity (or what he called impenetrability), bodies being extended and impenetrable, while incorporeal substance (soul or spirit) is extended and penetrable. He also took issue with Descartes over his denial of the possibility of a vacuum, rejecting final causes, and denial that animals have souls. He raised the problem of transmission of motion from one body to another, if motion like shape is merely a mode of body. He points up areas where Descartes is not fully self-consistent, or has dissembled his position, notably in positing the indefinite extent of the universe but not its infinity. He also criticized his account of refraction, and his vortical theory of celestial motions (see vortex). Descartes responded to More's letters in detail, though he evidently regarded More's arguments as too anthropomorphic for his liking.

The Duchess of Newcastle was a prolific authoress whose writings include several works on philosophical subjects. Her interest in natural philosophy was encouraged by her husband, William Cavendish, Duke of Newcastle (formerly Marquess), and his brother, Sir Charles Cavendish. Through the Cavendish circle she met both Descartes and Hobbes, although she denied having any significant contact with either. She was a beneficiary of the Cartesian turn in philosophy to the extent that she repudiated traditional book learning and took the thinking self as her point of departure. Her own philosophy is, however, fundamentally opposed to Cartesianism, since she denied dualism of mind and body, proposing instead a materialist and vitalist account of nature. In her Philosophical Letters (1664) and her Observations upon Experimental Philosophy (1666), she made specific criticisms of Descartes, particularly of his dualism – for example, she questioned how an immaterial substance could move a solid body, and his locating the human soul in the pineal gland.

See also Cavendish, William; Dualism; Hobbes, Thomas; Human Being; Pineal Gland

Cudworth was the most significant philosopher among the Cambridge Platonists. Only a fraction of his manuscript writings on ethics and epistemology was published, and that posthumously: his Treatise concerning Eternal and Immutable Morality (1731) and his Treatise of Freewill (1838). The major work published in his lifetime was his The True Intellectual System of the Universe (1678), an antideterminist analysis of philosophical atheism in all its manifestations, both ancient and modern. The humanist learning in which this book is steeped masks the modernity of his philosophical outlook and especially, perhaps, his admiration for Descartes. For although Cudworth had major criticisms of Cartesianism, Descartes informs his philosophy in fundamental respects. He lauded Descartes as the reviver of ancient atomism. He regarded the Cartesian conception of body as inert extension as the most intelligible account of corporeality, and the premise of a theory of immaterial (i.e., spiritual) causation. He shared Descartes’ view of mind as a distinct substance from body. And he took clear and distinct perception as the principle of epistemological certainty. However, Cudworth was also critical of Descartes. As concerns dualism, the operative distinction for Cudworth is not between mind and body, but between force and matter, active and passive. Incorporeality is not coterminous with the mental – all self-moving substance is incorporeal; and there are mental activities that neither are conscious nor involve cogitation – in other words, “unconscious.” For Cudworth, the boundaries of the incorporeal and corporeal are softened by his conception of “plastic natures” that govern life processes and direct the workings of nature toward providential ends. He was critical of Descartes’ theory of animal mechanism and rejected his proof of the existence of God based on the truth of our faculties as circular (see Circle, Cartesian). And he criticized Descartes’ rejection of final causes. The fundamental error of Cartesianism was its misidentification of God's will as arbitrary indifference, not subject to divine wisdom. Such a conception of the deity destroys both moral and epistemological certainty, opening the way to irreligion, skepticism, atheism. In his Treatise concerning Eternal and Immutable Morality, he develops the ethical dimension of the argument and lays the basis for a theory of active mind. His theory of mind is developed to an elaborate degree in his A Treatise of Freewill and in his unpublished manuscript writings “On Liberty and Necessity.”

See also Animal; Atom; Cartesianism; Cause; Circle, Cartesian; Dualism; Substance

The question of what educational background any particular philosopher might have had is normally discussed in terms of shaping influences, be these positive or negative, that the individual concerned might have received – for example, Descartes' grounding in mathematics at the Jesuit College at La Flèche or Locke's encounter with academic scholasticism at Oxford. In the case of a woman philosopher living at a time when education for women was the exception rather than the norm, the question of educational background becomes part of the wider question of how she came to philosophy at all. This is a question which is not usually asked about male philosophers, even when the information about their education is quite full. Besides, the broad categories of school and university training do not fit the seventeenth-century female subject very comfortably. Nor are they especially illuminating in Conway's case, unless they are set in relation to other circumstances, in particular her social background, her personal relationships and the state of philosophy and philosophical education in the 1640s and 50s.

That Anne Conway was highly educated there can be no doubt. The address to the reader which prefaces her Principles describes her as ‘a woman learned beyond her sex, most skilled in the Latin and Greek literature and especially well versed in every sort of philosophy’. However, the documentation of her education is patchy, consisting largely in the imperfect record that her surviving correspondence affords.

The anonymous manuscript treatise that lay unpublished among Anne Conway's papers was the culmination of a lifetime's interest in philosophy. In its final form, it was most probably produced no more than a couple of years before she died. But it is the outcome of on-going philosophical discussions which, as we have seen, may be traced back to her earliest study of philosophy. Her youthful doubt as to whether philosophy and religion are compatible opened the way to central questions about the nature of God, the world, and God's relation to the world – questions she tackled using the philosophical tools of Platonism and Cartesianism, and in the light of her study of contemporary natural philosophy. Central to her investigations were the issues of how material reality can be produced by an immaterial God, and how the existence of pain and suffering can be reconciled with the perfection of God. The ‘paper book’ Van Helmont found among her papers contained the answers to these questions in the form of a synthesis which explains the nature of the world through its causes. The resulting Principles is both a philosophy of nature and a philosophy of religion, a cosmology and a theodicy, in which the ultimate origin of all things is God.

The centrality of God is not unusual in seventeenth-century philosophy, but for Anne Conway what matters is not simply the existence of God, but the nature of God, because her system is founded on an analogy between God and the created world.