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Wrangling about Innate Ideas? Reflections on Locke and Cudworth

Theology and Philosophy Department, Lincoln Christian University, Lincoln, IL 62656, USA
Religions 2023, 14(3), 404;
Original submission received: 14 February 2023 / Revised: 9 March 2023 / Accepted: 13 March 2023 / Published: 16 March 2023
(This article belongs to the Special Issue New Voices in Philosophical Theology)


Locke contended that knowledge is learned from experience, taught from without rather than innately known from within. The notion of innate ideas has since been seen by many as innately ridiculous, as a battle long ago waged and won in the first book of Locke’s Essay Concerning Human Understanding. However, there was no fight in the first place, for the most comprehensive defence of innate ideas in the 17th century was not published until the 18th century. Ralph Cudworth’s Treatise Concerning Eternal and Immutable Morality was published posthumously nearly fifty years after its writing, and while Locke and Cudworth wrote on similar subjects—and around the same time and place—the fates never aligned for them to meet and ‘have it out’. This paper places Locke and Cudworth into conversation on this question of innate ideas. Such analysis will reveal that Cudworth sidestepped much of Locke’s critique by hanging his argument not on universal consent but on the Platonic principle of like-knows-like. In the process, Cudworth anticipated many of the responses to Locke that would come in the next century from Berkeley, Hume, and Kant. Thus, his forgotten role in this narrative in the history of philosophy cries out for reappraisal, along with the renewed insights he might bring to the on-going contemporary discussion.

The popular discussion of nature versus nurture has occurred on a primarily moral and sociological level—e.g., would Timmy have ended up in prison if his father loved him or if his mother fed him from her left breast?—for many assume that the epistemological question was long ago settled by John Locke. During the 17th century, Locke contended that knowledge is learned from experience: taught from without rather than innately known from within. With some exceptions (most recently Chomsky and the linguists), the notion of innate ideas has since been seen by many as innately ridiculous, as a battle long ago waged and won in the first book of Locke’s Essay Concerning Human Understanding. However, there was no fight in the first place, or at least, not the fight the people deserved, for the most comprehensive defence of innate ideas in the 17th century was not published until the 18th century, long past the death of Locke as well as the expiry date for optimum readership. Ralph Cudworth’s Treatise Concerning Eternal and Immutable Morality was published posthumously nearly fifty years after its writing, and while Locke and Cudworth wrote on similar subjects—and around the same time and place—the fates never aligned for them to meet and ‘have it out’. This paper intends to put Locke and Cudworth into conversation on this question of innate ideas. Such analysis will reveal that Cudworth sidestepped much of Locke’s critique by hanging his argument not on universal consent but on the Platonic principle of like-knows-like.1 In the process, Cudworth anticipated many of the responses to Locke that would come in the next century from Berkeley, Hume, and Kant. Thus, his forgotten role in this narrative in the history of philosophy cries out for reappraisal.
Such genealogies are not only important for the historian’s reconstructions of our past but for how we philosophically conceive and construct our present and future. The ongoing renaissance in Cambridge Platonist studies at the universities of Münster, Laval, McGill, Cambridge, and Bucharest (et al.) has been helping us reconsider modernity not as a necessary flight away from religion and toward reason but as a time and transition equally mediated by deeply religious figures such as Cudworth, More, or the other Cambridge Platonists. To reconsider the role of one such religious figure in the construction of our modern epistemology, and to show that many of our contemporary shifts could have been, and indeed were, accommodated and constructed within an explicitly religious framework, should help us reconsider the role of religion in our ‘enlightened’ world today.
In turn, the question of innate ideas has long been central to philosophical theology. The source of knowledge has often been considered indicative of the ontology of that which was known, bridging the soul and its higher source. Epistemological questions around innatism have remained central to arguments in the philosophy of religion, contrasting intuitive or internalist arguments for God with a more empirical approach, whether that be for the divine (e.g., Richard Swinburne) or against it. Further, questions about the origin of knowledge and language are perennial concerns in contemporary academia, whether in the more secular contexts of someone such as Noam Chomsky or in discussions surrounding theological speech and the (non)ability of language to univocally and/or analogously describe the divine. Indeed, if our knowledge is innate and comes not from temporal experience but from a former intimacy or on-going link with the eternal, then this opens up radical possibilities for what theological language (and language in general) can accomplish. Thus, this re-evaluation of Cudworth is a way to reconceive a history that is still unfolding in us and which can still lead to very different conclusions.

1. The ‘Almost’ Interaction of Locke and Cudworth

The tale of Locke and Cudworth is littered with near misses, with tantalizing moments of the two almost meeting and discussing innatism. Both Locke and Cudworth were born in Somerset county within the same generation and educated in similar circles at Oxford and Cambridge, respectively. While at Cambridge, Cudworth was deeply influenced by his teacher Benjamin Whichcote—the de facto founder of the Cambridge Platonists—who would later become Locke’s vicar at St. Lawrence in London (Cranston and Locke 1979, p. 124). Their mutual interest in philosophy, theology, and the rising sciences kept them in similar circles (Cranston and Locke 1979, p. 193), and while they differed on questions of epistemology, both Locke and Cudworth emphasized the dignity of humankind as well as the value of reason and its import for the cause of toleration (Broad 2006, pp. 496–99). However, their greatest link—written in blood and affection—was yet to come.
In 1681, Locke met Damaris Cudworth—daughter of Ralph Cudworth—who was “destined to be[come] closer to Locke than any other human being” (Cranston and Locke 1979, pp. 215–19). Raised at Cambridge—where her father was Master of Christ College—Damaris Cudworth displayed an uncanny depth and breadth of knowledge. Locke later wrote that Damaris was “a remarkably gifted woman … Her judgment is singularly keen … [and] beyond the grasp, I do not say of women, but even of the most educated men …” (Locke and De Beer 2007, p. 237) This meeting of minds soon evolved into one of the heart. They developed pet names for each other—Damaris was Philoclea and Locke was Philander—signing over forty intimate letters with these designations (Masham et al. 2003, p. 286). Locke would later even refer to Damaris as “a sister or a daughter, or something nearer than those relations” (Locke and De Beer 2007, p. 139). Yet Locke’s political views soon forced him into exile, and in his absence, Damaris married Sir Francis Masham. She later wrote a poem explaining that she had wanted more but Locke rejected her, only to change his mind when she was married and it was too late.2 While the full nature of their relationship is difficult to discern, it is clear that it had glimmers of something more than mere friendship, which makes what happened next all the more perplexing and—somewhat enjoyably—scandalous.
After the Glorious Revolution in 1688, Locke was able to return from exile, meeting with Lady Masham and her husband in London. Sir Francis Masham was either very understanding or very oblivious, for he invited Locke to make “a Tryal of the Air” at the Masham family home in Oates (Broad 2006, pp. 490–91). After finding his health restored by the country air, Locke decided to make the move permanent, allowing him and Lady Masham to spend the last decades of his life almost constantly together. Now, one would have hoped that Locke moving in with Cudworth’s daughter would have all but guaranteed an inevitable meeting between the two philosophers and, with any luck, a dialogue between them over innate ideas. However, it was not to be. Ralph Cudworth had just died in 1688, the very year that the Glorious Revolution would allow Locke to return from exile and move in with Lady Masham. Further, Locke’s Essay Concerning Human Understanding, with its opening rejection of innatism, did not appear until 1689, one year too late for Cudworth to respond to it. Conversely, while Locke was aware of Cudworth’s works—explicitly quoting him in a number of places (Broad 2006, pp. 489–510; cf. Armstrong 1969, pp. 187–202)—Cudworth’s comprehensive defence of innatism in the Eternal and Immutable Morality was only released posthumously in 1731, decades after Locke had died.
Locke continued to live with the Mashams until 1704, when he died peacefully one afternoon while Lady Masham read to him from the Psalms. In the end, despite their concurrent time, place, ideological circles, and even family connections, neither Locke nor Cudworth was able to directly face nor respond to the other regarding innate ideas. The conversation—so close yet so far—never happened. Such a dialogue is what this paper will now attempt to portray, placing the first chapter of Locke’s Essay toe-to-toe with Cudworth’s Eternal and Immutable Morality.

2. Summary of Cudworth’s Eternal and Immutable Morality

The Eternal and Immutable Morality (EIM) is concerned with two basic questions: what is the nature of the ethical, and how do we know it? Regarding the former, Cudworth is determined to defend the eternal and immutable nature of morality. Regarding the latter, he wishes to show that only innatism can yield knowledge of an eternal and immutable morality. He begins with the former question, reminding us of the many thinkers who ground morality not in an absolute nature but in the arbitrary inventions of the will. Cudworth traces this debate from Plato all the way up to his contemporary Thomas Hobbes, who asserts that
In the state of nature nothing can be unjust; the notions of right and wrong, justice and injustice have no place; where there is no common power, there is no law; where no law, no transgression … Sensuality, in that sense that it is condemned, hath no place until there are laws.
(Hobbes 1651, quoted from EIM 1731, p. 13)
This narrative makes morality a social construct; right and wrong are written not in eternity but on the parchment of parliaments and kings. Something is only immoral because the ruler declares it so and would become moral again if the ruler changed his mind. Cudworth maintains that there is a theological rendition of this narrative as well, found in Ockham and Descartes (EIM 1731, p. 22). Such thinkers maintain that God must be able to decide what is good and bad, or else he is restricted by a set of rules that are above him. Just as humans complain about the constraints of rules, so, too, God’s freedom and power would be impeded by any set of morals he must submit to. Morality according to such thinkers would not be grounded in the eternal and immutable nature of God (e.g., ‘God is love’) but in an “arbitrary” and changeable proclamation of the divine will, for only if God can bend morality to his will can he truly be all powerful. However, were this ‘will’ to change its mind, then greed could become good, love become lame, hate become holy, and up become down. All morality would become relative to the will of the sovereign, regardless of whether that sovereign be earthly (Hobbes) or divine (Ockham/Descartes/Calvinism). One person may say love is good, another that greed and self-preservation are good, and neither has any more claim to objectivity than children arguing over the rules of a game they just invented. Thus, in contrast, Cudworth concludes that morality must be eternal and immutable, for any morality invented by an arbitrary will would have no more claim than any other invented morality.
With the need for an eternal morality established, Cudworth precedes to the epistemological side of the question, demonstrating how this eternal and immutable morality can only be known through innate knowledge. Cudworth begins by wielding his personal brand of atomism, for external matter discloses only physical movement and not qualities. For example, not everyone sees the same colours—e.g., colour blindness—showing that the quality of colour is relative to the perceiving mind rather than merely an external reality.
Those ideas of heat, light, and colours, and other sensible things, being not qualities really existing in the bodies without us, as the atomical philosophy instructs us, and therefore not passively stamped or imprinted upon the soul from without in the same manner that a signature is upon a piece of wax, must needs arise partly from some inward vital energy of the soul itself, being phantasms of the soul, or several modes of cogitation or perception in it.
One does not perceive pure, raw, unadulterated matter in and of itself. Rather, the end product has been filtered and processed by the qualities and relations of the mind. A man and a beast may both look at the same page, and one mind will see meaningless scribble while the other mind finds the poetry and prose of the ages (EIM 1731, p. 99). The mind sketches the heights and depths of reality, filling in its many blanks, where lone perception is at a loss. Atoms merely provide the material ‘knock’ that awakens the qualities already latent in the mind (EIM 1731, p. 60). The mind is both active and passive in this process; it passively receives material pushes from the outside while actively imposing its own qualities upon those pushes:
Sense experience is but a kind of speech (loquela), if I may so call it, nature as it were talking to us in the sensible objects without by certain motions as signs from thence communicated to the brain.
However, we can only understand nature’s speech if we already know the language—if we already have its grammar and syntax latent in our minds. The mind cannot be “a mere naked and passive thing, a rasa tabula, which has no innate furniture or activity of its own” (EIM 1731, p. 144). “All knowledge”, he argues, “involves the activity of mind … knowledge is an inward and active energy of the mind itself” (EIM 1731, p. 93). This paves the way for Cudworth’s strongest argument, which will play a pivotal role in our dialogue with Locke.
Cudworth’s observations thus far have been ironically empirical, observing the perception process and the role the brain seems to play. However, now he moves from what happens to be the case to what must be the case. Cudworth reasons that if something is like us, then it is similar, and we must contain something like it within ourselves. However, if something is other, then it is dissimilar. Now, in order to perceive something that is truly other, we would have to build some kind of bridge of commonality by which we perceive it. However, then it would not truly be other, for there would be some shred of commonality by which we can understand it. Thus, if something is like us, then there is a commonality between knower and known, and what is known must in some sense already be contained within our brains prior to the actual experience. However, if something is truly other, then there is no way to come to know it at all, so the senses are limited to either tautology or ignorance. In Cudworth’s own words:
That which wholly looks abroad outward upon its object is not one with that which it perceives, but is at a distance from it, and therefore cannot know and comprehend it. But knowledge and intellection doth not merely look out (prospicere) upon a thing at a distance, but makes an inward reflection upon the thing it knows, and according to the etymon of the word, the intellect (intellectus) doth read inward characters written within itself (in interioribus legere), and intellectually comprehend its object within itself, and is the same with it … in Aristotle’s sense, it is unquestionably true, ‘In abstract things themselves’, which are the primary objects of science, ‘the intellect and the thing known are really one and the same’. For those ideas or objects of intellection are nothing else but the modifications of the mind itself. But sense is that which is without … sense wholly gazes and gads abroad, and therefore doth not know and comprehend its object, because it is different from it.
If something is truly other, truly different, then in order for it to be other, you cannot even perceive it in the first place, because whatever part of yourself could perceive it would have to be sufficiently like that thing, and so it would not actually be other. In that sense, you can never encounter something that is beyond the human mind, never gaze into the face of the other. Cudworth thus brought the Platonic principle of ‘like-knows-like’ to bear upon contemporary epistemology, for the mind “cannot know anything, but by something of its own, that is native, domestic and familiar to it” (EIM 1731, p. 74). One can only know what is already like, and in that sense the same as, itself.
However, this does not mean that children burst into the world asserting the law of non-contradiction from their cradles. Rather, they merely have the pre-disposition to begin to develop such beliefs over time. This view has become known as dispositional innatism, where we are born with an innate disposition that tends to lean toward the adopting of certain beliefs over time, rather than having fully formed ideas from our very birth. Descartes compared this to an inherited disease that lies dormant for years until triggered by age or diet. Cudworth stands in this tradition, picturing the external world as merely the field on which our natural dispositions are allowed to play out. Experience is—like Socrates in the Meno—a willing midwife, for a midwife does not create but merely delivers the child that was within all along (EIM 1731, pp. 78–79).
While this innate knowledge may be internal to the mind, that does not make it subjective, for Cudworth believes the innate ideas are “exactly the same” for everyone (EIM 1731, p. 131). Public thought and dialogue are possible because our many and diverse individual minds all participate (EIM 1731, p. 26) in one divine mind:
… it is but one truth and knowledge that is in all the understandings in the world. Just as when a thousand eyes look upon the sun at once, they all see the same individual object. Or as when a great crowd or throng of people hear one and the same orator speaking to them all, it is one and the same voice, that is in the several ears of all those several auditors. So in like manner, when innumerable created understandings direct themselves to the contemplation of the same universal and immutable truths, they do all of them but as it were listen to one and the same original voice of the eternal wisdom that is never silent ….
(EIM 1731, pp. 131–32, Italics added)
If eternal truths are only in the mind and not in the temporal realm of the senses, then only if there is an eternal mind can morality be eternal as well (i.e., divine idealism). Otherwise, morality would fluctuate in and out of existence depending on what species or individual minds exist at any particular moment. Further, while sense knowledge deals with the temporal (and so on its own could never give us knowledge of universal and eternal morals), innate knowledge is from the soul and so deals with the eternal and spiritual, giving us ‘like-knows-like’ access to an eternal morality grounded in the divine mind. It is only by our participating in this eternal mind that we can know eternal truths (EIM 1731, p. 128), and thus the innate categories of mind, rather than the experience of sense, is the key to knowledge.

3. Summary of the First Book of Locke’s An Essay Concerning Human Understanding

The first book of Locke’s Essay (Locke and Pringle-Pattison 1969) attempts to provide a sensory alternative to innatism, arguing that “the senses at first let in particular ideas, and furnish the yet empty cabinet, and the mind by degrees growing familiar with some of them, they are lodged in the memory, and names got to them. Afterwards, the mind proceeding further, abstracts them, and by degrees learns the use of general names” (Essay 1690, pp. 22–23). Locke begins by attacking the argument from universal consent, which asserts that since there are principles “universally agreed upon by all mankind” (Essay 1690, p. 17), therefore these principles must be innate, rather than contingent upon one’s unique context or development. However, Locke protests that there are not in fact such universal principles, noting that “children and idiots” (Essay 1690, p. 18) cannot articulate, for example, the law of non-contradiction, and that a “great part of illiterate people and savages pass many years, even of their rational age without ever thinking on this and the like general propositions” (Essay 1690, p. 21). One might respond that these propositions are immediately assented to once people do encounter them and so possess an innate certitude that is obvious to anyone who stops to think about them. However, Locke contends that any innate truth that has to be pointed out is not worthy of the name, for “how can it with any tolerable sense be supposed, that what was imprinted by nature, as the foundation and guide of our reason, should need the use of reason to discover it?” (Essay 1690, p. 21) If the obviousness of a principle upon reflection is all that delineates something as innate, then innatism proves little by proving too much, for then
“that one and two are equal to three, that sweetness is not bitterness”, and a thousand the like, must be innate … I demand whether ready assent given to a proposition, upon first hearing and understanding the terms, be a certain mark of an innate principle? If it be not, such a general assent is in vain urged as a proof of them: if it be said that it is a mark of innate, they must then allow all such propositions to be innate which are generally assented to as soon as heard, whereby they will find themselves plentifully stored with innate principles … that “it is impossible for the same thing to be and not to be”, that “white is not black”, that “a square is not a circle”, that “bitterness is not sweetness”. These and a million of such other propositions … this will be to suppose all our ideas of colours, sounds, tastes, figure, &c., innate, than which there cannot be anything more opposite to reason and experience.
In turn, if one argues the dispositional theory of learning, wherein experience merely awakens what was already innate, then innate merely comes to describe anything the mind is capable of knowing. However, this definition could extend to everything, and so even the knowledge that Caesar crossed the Rubicon or that Franz Ferdinand was assassinated in 1914 could become innate, which seems patently absurd.
If the capacity of knowing be the natural impression contended for, then all the truths a man ever comes to know will, by this account, be every one of them innate; and this great point will amount to no more, but only to a very improper way of speaking; which, whilst it pretends to assert the contrary, says nothing different from those who deny innate principles. For nobody, I think, ever denied that the mind was capable of knowing several truths. The capacity, they say, is innate; the knowledge acquired. But then to what end such contest for certain innate maxims? If truths can be imprinted on the understanding without being perceived, I can see no difference there can be between any truths the mind is capable of knowing in respect of their original: they must all be innate or all adventitious; in vain shall a man go about to distinguish them.
Locke’s attack now shifts from reason to ethics. While there may be no rational truths that are innate, is it possible that there could be moral truths written upon our hearts? “Where is” he asks, “that practical truth that is universally received, without doubt or question, as it must be if innate?” (Essay 1690, p. 28) Par for the course, Locke argues that there are no such truths, for
Have there not been whole nations, and those of the most civilized people, amongst whom the exposing their children, and leaving them in the fields to perish by want or wild beasts has been the practice; as little condemned or scrupled as the begetting them? … In a part of Asia, the sick, when their case comes to be thought desperate, are carried out and laid on the earth before they are dead; and left there, exposed to wind and weather, to perish without assistance or pity … The Caribbees were wont to geld their children, on purpose to fat and eat them.
Local “custom” is a “greater power than nature” (Essay 1690, p. 35). Our deepest beliefs come “from no better original than the superstition of a nurse, or the authority of an old woman [and] may, by length of time and consent of neighbours, grow up to the dignity of principles in religion or morality” (Essay 1690, p. 34). This elevation to innate gives an unquestionable status to our beliefs, revealing Locke’s true target to be both philosophical and political, for those equipped with the fire and ferocity of innate truth will kill and die defending what is, in fact, only local custom. This played out in the Thirty Years War that endured through Locke’s childhood as well as the English civil strife that eventually sent him into exile. Thus, Locke closes with a plea for independent thought and exploration, questioning all truths that are alleged to be innate and therefore unquestionable (Essay 1690, pp. 35–36).

4. A Cudworthian Critique of Locke

Facing Locke, it is clear that Cudworth would have trouble launching any offensive that argues from universals. However, Cudworth is able to drop this premise without negating the power of his underlying argument. He argues that any investigation into the universality of innate ideas is oxymoronic, as this investigation must always be empirically directed toward individuals and cultures outside of ourselves, and so it would—by definition—be unable to reach any absolute morality, as the empirical can only ever deal with the particular (EIM 1731, pp. 133–34). In fact, for Cudworth, it is precisely the non-universality of innate ideas that make them valid, for while one can either be right or wrong about innate truths (EIM 1731, p. 137), sense experience
is not capable of falsehood, because as such it does not comprehend the absolute truth of any thing, being only a phantasm or appearance, and all appearances as such are alike true. So in like manner, if the noetical perceptions of the soul were only fantastical, and did not extend to the comprehension of the absolute truth of things, then every opinion would of necessity be alike true, neither could there be any absolute falsehood in any, because ‘every fancy is true’.
While Cudworth obviously believes certain things to be universal, by the end of the EIM, he is willing to dispose of that defence altogether, writing that even if there
were a world of men created either in the moon or elsewhere, that should affirm the contradictories to all the theorems in geometry … we ought not in the least to question from hence whether our faculties or theirs were made true, or to suspect that truth and knowledge were such whiffling things, as that they merely depended upon an arbitrary make of faculties. But [we ought] to conclude without any controversy that this was but a bedlam world of mad, frantic, and distracted souls, that had no clear apprehensions of any thing, and either by mere chance or humour happened to assent to every thing that was false as true.
Thus, Locke’s critique of universality, considered by many to be the battering ram of empiricism, cannot even make it to Cudworth’s door, for his defence is built on much higher ground. It rests instead atop the old Greek fortress of like-knows-like.
While Locke looks at the external world to investigate what seems to be the case (e.g., non-universality), Cudworth attempts to argue from what must be the case, based on the principle of like-knows-like (LKL). For how can new knowledge reach the island of the self, unless there be some univocal bridge by which to get there, some island chain by which the known is already linked with the knower? This section will show how Cudworth’s use of LKL could critique Book One of Locke’s Essay, arguing that (1) knowledge in general and (2) Locke’s specific beliefs in God and morality necessitate some form of innatism.
To illustrate the principle of LKL in general, Cudworth uses the example of recognizing a face in the crowd (EIM 1731, p. 74). One does not recognize a face in the crowd unless they already have some ‘like’ notion of them in their mind, some pattern in their mind by which they recognize a familiar face. However, Locke would to some extent agree. He does not deny that the adult mind has ideas through which it filters reality, but only that these ideas originated in the mind. The Lockean can retort that one’s memory of a friend in the crowd would itself be based on something learnt, e.g., on their prior sensory experience of encountering the person many years before at school or at a friend’s home. While this is a good retort, it makes Locke’s criteria almost impossible to meet—and perhaps even unfalsifiable—for how could one experience what is prior to experience? Even if we could figure out a way to communicate with, say, a human infant, Locke could respond that an infant has already existed in the world for weeks, observing shapes and sounds and colours, in addition to their many months in the womb, which is itself an experience of sorts (Essay 1690, pp. 25–26, 74). Thus, rather than making a comparison between earlier and later stages of human development, Cudworth wisely switches to comparing human and non-human species:
But if intellection and knowledge were a mere passive perception of the soul from without and nothing but sense, or the result of it, then what reason could be given why brute animals that have all the same senses that men have, and some of them more acute, should not have intellection also, and be as capable of logic, mathematics, and metaphysics, and have the same notions of morality, of a deity and religion that men have? … there is in the souls of men another more active principle or an innate cognoscitive power, whereby they are enabled to understand or judge of what is received from without by sense.
Indeed, what is it about the human brain, as opposed to that of a mollusc, that allows us to develop the categories necessary for language, art, mathematics, or religion? If the human mind brings nothing to the table, and all is a matter of experiencing the world, then why are hamsters—who dwell in the same external world as humans—not capable of similar intellectual feats? Since the external world of matter is the same for a Baron as for a beast, then is it not the internal difference of brain capacity that makes all the difference? One may insist that other species do, in fact, have their own form of intelligence (e.g., some species have brains that can process information from three or more eyes at once), but this would only serve Cudworth’s point, showing that different brains bring different filters to reality, only processing what is similar to (i.e., like) the cognitive categories of one’s own species. Thus, Cudworth can rise to the challenge and provide real-world examples for LKL. However, he need not play that game in the first place. To enter into Locke’s epistemology and provide experiential examples might be to have already lost the argument. The real power of Cudworth’s position—as will now be shown—is that it is true by sheer definition.
By definition, that which is other cannot be known, for if it were knowable, this would suggest some continuum between us and it, which could be traversed in order to come to know it. Then, however, it was never truly other in the first place, for there was some common ground all along, some ‘like’ terrain that could be tread to reach it (EIM 1731, p. 59). An overly simplistic—but perhaps still helpful—illustration would be that of ‘other’ ethnicities. They may seem other, but we can come to know and accept each other by embracing our common humanity, i.e., by realizing we are not truly other at all. However, authentic otherness would be closer to a two-dimensional entity attempting to conceive of a three-dimensional one or a logical mind attempting to fathom a square triangle. Beating Kant to the punch, Cudworth lists numerous categories of the mind (including cause and effect, see EIM 1731, p. 80) that sketch the limits of our reality, for how could we perceive objects in space and time unless we ourselves thought in temporal and spatial categories? Our reality must already be contained within the limits of our mind, and anything that is beyond our conceptual capacities would simply not be perceivable at all, such as trying to stare at the sun (EIM 1731, p. 76). The known must always be lurking down deep within the knower, waiting until the conditions are perfect to bubble back up to the surface. Quoting Aristotle, Cudworth writes that “that which knows and that which is known are really the same thing …” (EIM 1731, p. 135). Locke could press Cudworth’s examples as far back as he likes, locating ideas in infancy, but basic logic shows that at no point could one have experienced something they were not cognitively capable of experiencing; there is, if you will, no cognitio ex nihilo. Like can only know like.
While the above discussion pitted the principle of LKL against Locke’s view of knowledge in general, this principle could also be applied to Locke’s specific beliefs, particularly concerning the existence of God and morality, for it is one thing to say our material senses can grant new information about the material world, and quite another to say they can grasp trans-material, spiritual, eternal truths (i.e., that which is utterly dissimilar). Now, Locke was a deeply religious man, a fact which is sometimes not appreciated because he spent so much energy and time attacking orthodox religion. His religion was that of the Latitudinarian wing of the Church of England. His creed was short, but he held to it with the utmost assurance (Cranston and Locke 1979, p. 124).
Religion was a primary theme in many of Locke’s works, and most of his other writings, when “properly contextualized, also bear upon it” (Locke and Nuovo 2002, p. XV). Though he never finished a systematic theology, he did outline how it would be arranged, and the Essay Concerning Human Understanding initially began as an inquiry into the “true principles of morality and revealed religion” (Cranston and Locke 1979, pp. 140–41). Locke writes that
I think it unavoidable for every considering, rational creature, that will but examine his own or any other existence, to have the notion of an eternal, wise Being, who had no beginning: and such an idea of infinite duration I am sure I have.
In turn, Locke believes morality is founded not merely on the changing whims of humanity but upon the divine:
But there is an other sort of Morality or Rules of our actions which … have a different foundation … not being Ideas of our own makeing to which we gives names but depend upon some thing without us & soe not made by us but for us ... These are properly & truely the rules of good and evill … we come by from the rules set us by a Superior power … This Soverain Law maker who has set rules & bounds to the actions of men is god their maker whose existence we have already proved.
(Of Ethic in General, pp. 10–11, Quoted from Locke and Nuovo 2002, pp. 12–13)
In other words, Locke was not Hobbes. Whereas Hobbes might have avoided Cudworth’s critique by simply abandoning God or a higher morality, Locke leaves himself no such option, allowing Cudworth to inquire how material experience could paint a picture of that which—being immaterial and spiritual—is utterly unlike it.
Now, Cudworth contends that anyone who rejects innatism rejects morality itself (EIM 1731, pp. 144–45). Foreshadowing Hume’s ought/is distinction, Cudworth maintains that matter cannot contain higher morals, but is simply raw material flinging back and forth (EIM 1731, p. 112). Sense can teach us how ‘the good’ is defined in Victorian England, ancient Greece, or Mao’s China, but it cannot transcend its very nature to rise above the temporal and declare the eternal nature of good-ness itself. To know an eternal and immutable morality, there must already be some spark—i.e., the soul—of the eternal and immutable innate within us by which we know it: “the nature of morality cannot be understood without some knowledge of the nature of the soul” (EIM 1731, p. 145). There must already be some speck of likeness innately lodged within our mortal coils. The same problem applies to the divine. While Locke believes that creation declares the glory of God (Essay 1690, p. 37), his experiential epistemology could never glimpse God in and of himself but only see particular, culturally relative projections of him (EIM 1731, pp. 132–33). There would be no starting standard by which to judge that God loving the world is superior to Saturn eating his son. All gods and goods would become relative. Someone like Hobbes may have been willing to accept this, but Locke would certainly have not. Thus, Cudworth can provide both a general and a specific case against Locke using the principle of LKL. The next section will now imagine how Locke might have responded to such an accusation.

5. A Lockean Response to Cudworth’s Objection

While Locke does not directly attack the principle of LKL, one could assume he would employ the same response to Cudworth that he gave to the dispositionalist and immediate assent accounts. He could argue that LKL proves little by proving too much, for then everything could be called innate (Essay 1690, pp. 23–24). The principle of LKL could theoretically be used to render not only morality or the law of non-contradiction innate but the entire pantheon of knowledge as well. In order to know the difference between yellow and red, must the mind have a like notion of colours within it prior to any actual sight? Must the mind have a like notion of Lincoln’s death to discover he was shot in a theatre on 14 April 1865? This could go on ad absurdum, rendering innate truths indistinguishable from any other (Essay 1690, p. 18). Thus, while Locke does not show how the underlying principle of LKL is actually wrong, he could be used to show that it must be in one way or another, or else absurdity would result. All things would become innate, in which case ‘innate’ becomes a designator of nothing specific at all (Essay 1690, p. 18). The legacy of Locke’s objection continues today: Stephen Stich says that such extreme innatism renders an account “humdrum”, and is a sure sign that what may have once been an “exciting thesis” has now become “philosophically uninteresting” (Stich 2011, pp. 2–3). Thus, Cudworth proves little by proving too much, and this paper must now deal with Locke’s objection if Cudworth’s account is to be taken seriously.

6. A Cudworthian Response to Locke’s Critique of LKL

Cudworth’s work suggests three ways one might respond to Locke’s objection that LKL absurdly renders all things innate. First, atomism provides Cudworth with a way to distinguish innate and non-innate beliefs. Second, LKL would not require that everything be innate, for there could still exist many things beyond the mind’s reach. Finally, even if Locke’s accusation is correct, Cudworth is all too willing to embrace such an all-encompassing idealism, protecting himself from its more relativizing or solipsistic implications by making it a divine idealism.
First, Cudworth’s atomism could provide a structure by which innate and non-innate ideas could be distinguished. Atomism helps demarcate the lines of knowledge, for just as swirling atoms of matter do not contain higher qualities, the mind does not contain or choose the vulgar thrusts of material objects (EIM 1731, p. 51). While the notion of colours may be innate, the knowledge of what specific colours we will see walking down the street tomorrow is not and varies depending on the unique mixture of atoms and objects (EIM 1731, p. 105). The brain contains all the innate qualities of existence (e.g., time and space), but only sense can inform us of the unique mixture of those qualities that we encounter in the world (e.g., that at the time 1492, Columbus sailed through the space of an ocean blue). The brain has all the puzzle pieces, but only experience can show us how they are actually put together. Thus, not all would be rendered innate, and the contingent realms of history, science, and experiential knowledge would still have its place in the EIM.
However, Locke could still argue that if the principle of LKL truly holds, then it would apply not just to qualities but to the quantitative mixture of those qualities, and that Cudworth’s distinction between innate quality and external quantity is an arbitrary one; in “vain shall a man go about to distinguish them” (Essay 1690, pp. 18–19). In order to allow certain types of knowledge to escape the clutch of the innate, Cudworth must defy the principle of LKL in some—albeit small—way. However, if small violations are allowed, then why not bigger ones; why not push through and make the tear larger? These are difficult questions to answer, but they are just as difficult for Locke as for Cudworth. Indeed, the same accusation could be turned back on Locke’s line between primary and secondary qualities. Locke defines primary qualities as utterly
inseparable from the body, in what state soever it be … These I call original or primary qualities of body, which I think we may observe to produce simple ideas in us, viz. solidity, extension, figure, motion or rest, and number.
In turn, secondary qualities are
nothing in the objects themselves but power to produce various sensations in us by their primary qualities, i.e., by the bulk, figure, texture, and motion of their insensible parts, as colours, sounds, tastes, &c. These I call secondary qualities.
Thus, primary qualities are truly in the object itself, while secondary qualities are not. Secondary qualities are evoked by the external object (“produce various sensations”) but not in the external object. I.e., the object is not actually red, but its particles are arranged in such a way as to cause the brain to see red (Essay 1690, p. 69). Now, this sounds suspiciously close to the dispositionalist account which Locke already rejected. More importantly, how is this line between secondary and primary qualities to be held? Cudworth argues that even matter itself could be reduced to secondary qualities (EIM 1731, p. 101), and that the soul only has indirect contact with the world of objects through its own body (EIM 1731, p. 66). We can thus have physically stimulating dreams and hallucinations without anything externally present (EIM 1731, pp. 67, 70–72), potentially reducing all primary into secondary qualities, with any line between them drawn merely for the sake of whichever empiricist or innatist system is under discussion. Therefore, if distinguishability is indeed a problem, it is equally a problem for both Cudworth and Locke. Locke is in danger of falling into his own trap, and the slackening line between primary and secondary qualities is not strong enough to pull him out.
Second, LKL would not require that everything be innate, for many things could still exist beyond the mind’s reach. The Platonic tradition, writes Stich, does not “bloat the concept of innateness to encompass all knowledge, but rather shrink[s] the concept of knowledge until it coincides with what we know innately” (Stich 2011, pp. 2–3). The mind does not know all innately, for there may be many things beyond our cognitive categories. Cudworth hints at this when discussing the inaccessibility of the thing in itself:
the soul by sense doth not perceive the things themselves … it doth not take immediate cognizance of those very motions immediately as they are in themselves ….
(EIM 1731, pp. 62, 63, Italics added)
Nay, undoubtedly so long as we consider these things no otherwise than sense represents them, that is as really existing in the objects without us, they are and must needs be eternally unintelligible.
(EIM 1731, p. 57, Italics added)
[the soul does not] perceiv[e] them as they are in themselves … it does not perceive them in the same manner as they absolutely exist without us ….
(EIM 1731, pp. 52–54, Italics added)
We do not have knowledge of matter in itself, for sense is deceitful and the mind covers over raw matter by imposing its own categories upon it, such as cause, effect, means, end, order, proposition, similitude, dissimilitude, equality, inequality, aptitude, inaptitude, symmetry, asymmetry, whole and part, genus and species, and the like (EIM 1731, pp. 82–83).
Thus, there are inklings in Cudworth of what could anachronistically be deemed the ‘noumenal’. Cudworth here foreshadows what was only appreciated a century later through Hume and Kant regarding the non-empirical nature of causality and a noumenal/categorical response to it. As long as there is a noumenal realm that is ‘unlike’ us, the principle of LKL need not render all things innate.
Finally, even if the previous defences fail against Locke’s claim that all becomes innate, Cudworth could blithely retort “So what?” Indeed, Cudworth seems quite comfortable embracing an all-encompassing idealism. Locke’s threat that LKL would render everything innate is like threatening to beat the masochism out of a child. Cudworth runs to idealism with joy and a fattened calf, eagerly relocating more and more of reality into the mind, writing that the “several relative ideas of cause, effect, symmetry, proportion, order, whole and part, and the like … be only in the intellect itself”. And “yet”, Cudworth continues, “notwithstanding, the intellect doth not forge or falsify anything in apprehending of them” (EIM 1731, pp. 88–89). This last line is key, for while Cudworth does not share the fears of Locke and company, he does understand what lies beneath those fears. He, too, wants reality to be more than a mere subjective plaything of our own making. For Cudworth, knowledge is in, but not of, the human mind:
And yet, notwithstanding, though these things exist only in the mind, they are not therefore mere figments of the understanding … they have a constant and never-failing entity, and always are, whether our particular minds think of them or not ….
Yet how can Cudworth maintain such an objective reality, if the qualities of existence are merely in the mind? Because even though human minds may falter or pass away, there is an eternal mind in which all qualities of existence are eternally grounded (EIM 1731, p. 128). If all the colour and juice of reality is a thing of mind, then without an everlasting mind, reality is nothing but a subjective plaything of human fancy to be twisted and rewritten in the image of man. Indeed, Berkeley’s response to Locke was preceded by Cudworth, who says there must “of necessity be some one universal mind, the archetypal and exemplary cause of the whole mundane music” (EIM 1731, pp. 96–97). There must be a “sun that never sets, an eye that never winks” (EIM 1731, pp. 130–31).
Ironically, Cudworth’s divine idealism does not negate Locke’s beloved science but rather props it up. For if left to the senses alone, then men would not be
readily furnished with the ideas to conceive all things by at every time, it being merely casual and contingent what things occur to men’s several senses. Neither could their ideas be exactly alike to one another, because no individual objects are so. And therefore when one spoke of one thing, another would mean another … men could not possibly confer and discourse together in that manner as they do, presently perceiving one another’s meaning, and having the very same conceptions of things in their minds, if all did not partake of one and the same intellect. Neither could one so readily teach, and another learn, ‘if there were not the same ectypal stamps of things in the mind both of the teacher and the learner’.
Sense on its own would make knowledge relative to divergent experiences, turning science into a fully subjective discipline. However, if all minds share in a common, unified source (i.e., a divine mind), then a global community of authentic conversation and commensurability is possible. This not only grounds science, but provides a commonality by which different religious, ethnic, and social groups can communicate, enabling innatism to have the same potential for fruitful dialogue and tolerance that is often thought to be exclusive to Locke’s account. Locke believed it was precisely when inner sentiment trumps evidence that religious wars occur over differing convictions. Conversely, Cudworth maintained that since everyone’s experiences are different depending on their context, we can only be united by our commonly inherited notions (EIM 1731, p. 132). Locke believes innatism negates tolerance and reason while Cudworth thinks it is the only thing that can actually affirm them, for otherwise there is no innate commonality that can bridge the diversity of our unique contexts and experiences. Such a commonality must be provided by the mind of God, in whose image we are made and so commonly share in as siblings.
Now, Locke could obviously object that this divine idealism is a return to an argument from universal acceptance, for all are alleged to share in universals through the mind of God. However, there is a certain sense in which Locke also believes in universals: the universality of material science. Of course, this is not an innate universality, for not all cultures practice science or acknowledge its basic principles. However, the empiricist must believe that if one is properly educated in the sciences, then these taught principles will become clear, or else science would sink back into the very subjectivity it claims to transcend. The beauty of science is precisely its universality, that any person across the globe could go out and repeat an experiment and get the same results (Essay 1690, pp. 59–60).
Because matter is allegedly the same for all, universal truths can arise from it, giving science its beloved objectivity. Locke writes of such universal consent (“no one will deny”) regarding an array of notions, including solidity, number, pure space, existence, and unity:
Existence and Unity are two other ideas that are suggested to the understanding by every object without ….
(Essay 1690, p. 63, Italics added)
Amongst all the ideas we have, as there is none suggested to the mind by more ways, so there is none more simple, than that of unity, or one: it has no shadow of variety or composition in it: every object our senses are employed about; every idea in our understandings; every thought of our minds, brings this idea along with it. And therefore it is the most intimate to our thoughts, as well as it is, in its agreement to all other things, the most universal idea we have.
(Essay 1690, pp. 120–21, Italics added)
But my question is, whether one cannot have the idea of one body moved, whilst others are at rest? And I think this no one will deny.
(Essay 1690, p. 58, Italics added)
Locke even explicitly refers to certain notions as garnering “universal assent”:
On this faculty of distinguishing one thing from another depends the evidence and certainty of several, even very general, propositions, which have passed for innate truths; because men, overlooking the true cause why those propositions find universal assent, impute it wholly to native uniform impressions ….
(Essay 1690, p. 85, Italics added)
Of course, in this quote Locke also reminds us that these universals are known from experience, and it would be a mistake to “impute it wholly to native uniform impressions”.
However, it is too late, for Locke has admitted that certain truths are universally recognized, or at least, recognized immediately upon being exposed to them through scientific education. This would merely be the dispositionalist account seen from the other end; a universal that is taught to the mind at some point would be factually indistinguishable from a universal that is awoken in the mind at some point. Now, Locke’s usual retort to such a claim of dispositionalism was that it would render all things innate. However, as was shown earlier, this is equally a problem for his own distinction between primary and secondary qualities, and so his line in the sand has been washed away. Locke has admitted the truth of universals, while failing to provide a sufficient reason why they cannot fit into divine idealism as consistently as they do into his empiricist system.
Since this universality is conceptually consistent with both the innatist and empiricist accounts, it cannot be used as the deciding premise to prove one over the other (similarly, if two applicants for a scholarship have equal grades, then grades alone cannot be the deciding factor.) However, this impasse actually works for Cudworth and against Locke, for innatism does not need universality as a premise (EIM 1731, pp. 140–41), only as a conclusion. While Cudworth clearly believes that certain things are universally accepted, he does not think their universality needs to be empirically provable, for to prove a universal using a particular is an oxymoron (EIM 1731, pp. 133–34). The empiricist could retort that this ‘hiddenness of evidence’ is unfalsifiable and enables one to justify belief in anything. Yet this would only be a problem if idealism was epistemically justified based on an experience of universals, which it is not. Cudworth’s argument for innatism and idealism does not need universals as a premise, but merely draws it as a conclusion. The true justification for the argument does not come from the appearance of universality but from the powerful premise of LKL. In contrast, empiricism does rely on universality as the premise for its validity, for it is precisely the ability of a scientist in Geneva to test the results of one in Tokyo that proves the alleged objectivity and supremacy of empiricism. Ironically, any critique of universality would be far more damning to an empiricist who relies on it as the premise for their worldview than for Cudworth who can merely use it as an outflowing implication of the principle of LKL. Since both accounts embrace universality, it is doubly valid for Cudworth to maintain it as a conclusion, while being invalid for Locke to use it as a premise arguing one side over the other, for it is consistent with both.
Thus, Cudworth not only provides an alternate epistemology to Locke’s, but one that manages to justify the science and tolerance that Locke wished to justify, while avoiding the pitfalls of subjectivity that Locke and others wished to avoid. What is more, Cudworth manages to do all this while sidestepping the Lockean critique of universality, which, as it turns out, can be turned back upon empiricism itself (which uses universality as a premise rather than just a conclusion). Thus, Cudworth provides a coherent and intriguing picture of mind, reality, and the means by which the one accesses the other. Had this other side been sufficiently heard, the history of philosophy may have played out differently in a number of key areas. As Armstrong writes:
Locke’s rejection of the innate idea theory is … somewhat unfortunate. It threw his successors in this line of thought, Berkeley and Hume, off the right track. For if Locke had not been so adamant about innate ideas the suggestions of More and Cudworth regarding the active role played by the mind in the process of sensation could have been developed in eighteenth century England. As it turned out, however, this development was to wait for Immanuel Kant.

7. Conclusions

While this paper has not settled the question of innate ideas once and for all, it has shown that Locke did not accomplish this either. Due to Cudworth’s hesitation to publish, Locke did not have the chance to wrangle with the most comprehensive defence of innate ideas in the 17th century, leading to a one-sided narrative that came to define enlightenment mythology (and which continues to define the narratives we construct and tell ourselves today, both within and outside of philosophical theology). Had the other side of that tale been told, perhaps history would have seen that Locke himself struggled with the materialistic limits of empiricism (i.e., he was not Hobbes), and that Cudworth’s critique of empiricism, which re-emerged in Kant’s transcendental philosophy, deserved a much better hearing. This paper has attempted to imagine how such a ‘hearing’ might have played out. Cudworth would have spoken up for the principle of LKL, only for Locke to laugh and retort that this proves little by proving too much, rendering all things innate. Cudworth could then have turned the accusation back on Locke, for the same problem occurs in the distinction between primary and secondary qualities and can only be solved by divine idealism. Thus, while it would be over-reaching to declare a victor, this paper has shown that Cudworth provided a plausible alternative to Locke on the question of innate ideas, without which 17th century British empiricism is left like David without Goliath, Napoleon without Nelson. And just as the Napoleonic wars reshaped Europe and the globe for centuries to come, so, too, our modern intellectual landscape has been, and continues to be, shaped by the telling and retelling of this early modern struggle (or lack thereof).


This research received no external funding.

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Conflicts of Interest

The author declares no conflict of interest.


As explored extensively throughout the Meno, Phaedo, Phaedrus, et al.
B.L. MSS. Locke, c. 17.


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