Features of space

For Newton, space is an existence condition for any substance and ‘an affection of every kind of being’.Footnote ⁶ This latter description refers to the manner of existing in nature, a manner of existing quite different from that of an abstract entity or a number, as J. E. McGuire has explained.Footnote ⁷ As space is an affection of every kind of being, so is it a condition for their existence. As Newton asserts in a well-known remark, one repudiating the concept of spirits as transcendent, ‘No being exists or can exist which is not related to space in some way. God is everywhere, created minds are somewhere, and body is in the space that it occupies; and whatever is neither everywhere nor anywhere does not exist.’Footnote ⁸

Since space is an existence condition of substances, it is not surprising that Newton takes it to have its own manner of existing. It is neither substance, he emphasizes, nor accident.Footnote ⁹ That it is not an accident inhering in a subject means, in part, that as an affection of every kind of being, it cannot be localized to or associated with any one created being. Accordingly, it is independent of bodies; if all bodies were annihilated, it would continue to exist unchanged.Footnote ¹⁰ Space more nearly resembles a substance than an accident, Newton indicates, and as we shall see later, he ascribes a degree of ‘substantial reality’ to it. Indeed, he cites it as the one thing that can in some circumstances be conceived apart from God – a feature he will use to attack Descartes's account of matter as atheistic.Footnote ¹¹ Yet though it has some substantial reality, space is not a substance. For one thing, it is ‘not absolute in itself, but is as it were an emanative effect of God’.Footnote ¹² Its not being absolute could not alone explain its failure to qualify as a substance; for created substances too are not absolute in themselves, being dependent upon God. Yet created substances have a different relation to God, precisely in virtue of having been created. There is also another important difference. Substances act, whereas space produces no effects.Footnote ¹³

Though neither substance nor attribute, space is not nothing, Newton emphasizes, for it has properties. The properties he describes indicate a Euclidean space, three-dimensional, homogeneous, and infinite. Space is also eternal and immutable, and though parts may be distinguished within it, those parts are motionless and indivisible.Footnote ¹⁴ It is these features – the immobility and indivisibility of space's distinguishable parts – that are especially significant for Newton's account of body.

The creation hypothesis and the definition of body

Newton develops his creation hypothesis in two stages, first ignoring mobility but subsequently introducing it. He begins from the realization that we can temporarily make regions of space impervious to other bodies by moving our own bodies into them, observing that this might somehow simulate the divine power of creation. By his will alone, God ‘can prevent a body from penetrating any space defined by certain limits’.Footnote ¹⁵ Such an entity would either be a body, or would be indistinguishable from bodies by us.Footnote ¹⁶ For if God made some region above the earth impervious to bodies and all ‘impinging things’, it would be like a mountain; it would reflect all impinging things, including light and air, and it therefore would be visible and coloured, and would resonate if struck.Footnote ¹⁷

These entities would be very similar to corporeal particles, Newton notes, except for this important feature: as he has imagined them thus far, they are motionless. For an entity to be a body, or at least to resemble bodies in all humanly perceptible ways, it must be mobile. He therefore now adds that the hypothesized entities be capable of being moved from place to place, and in a law-governed way, a feature that is relatively new to conceptions of body.Footnote ¹⁸ Additionally, the entities can stimulate perceptions in minds and be operated upon by minds.Footnote ¹⁹ The hypothesized entities are now just like bodies, being perceptible, and having shape, tangibility, mobility, and the ability both to reflect and be reflected. They therefore could be ‘part of the structure of things’, just like ‘any other corpuscle’.Footnote ²⁰ This enables Newton to provide a definition of body (insofar as we can know them).

One of the interesting things about this definition is that Newton sees it as serving theological goals, as will become evident from his commentary, and yet it is firmly rooted in experience. The fundamental features of our experiences of bodies appear in the definition: their mobility; the mutual impenetrability that results in law-governed reflections of other bodies, light, and air; and the sensations they produce in us, such as those of colour. Newton's remark at the end of the passage highlights the fact that experiences, specifically perceptions, make his description of the bodies’ origin possible; if bodies lacked the power to produce sensations, we could never have any ideas of them.Footnote ²² It is notable that Newton specifies condition (3), the power to produce sensations, as distinct from condition (2), impenetrability. One reason for distinguishing them is that in the hypothesis's context – the first creation of matter – impenetrability could not be sufficient to produce sensations in minds. For if any minds existed when God first created matter, no human bodies would exist to touch that matter, and so the mutual impenetrability of bodies could not then produce sensations in minds. Yet there is another explanation for the inclusion of condition (3) as independent of condition (2): even in the context of actual experiences, Newton does not seem to consider sensations as explicable solely in terms of impenetrability. He rather seems to share a belief common in the early modern period – that while the contact of light particles with the eye and food particles with the tongue seem to play some necessary role, they are not sufficient for the production of sensation, and so some role must be attributed to God.Footnote ²³

The definition's third condition is thus the basis for Newton's claim that Descartes's account of matter leads to atheism, while his own confirms God's existence. As indicated above, he takes space to be the one thing sometimes conceivable apart from God, since it produces no sensations or other effects, and so by identifying matter with extension (space), Descartes allows that matter is conceivable apart from God.Footnote ²⁴ For as Newton indicates elsewhere, ‘we find almost no other reason for atheism than this notion of bodies having, as it were, a complete, absolute and independent reality in themselves.’Footnote ²⁵ On his own account, bodies are not conceivable apart from God, because their capacity to produce sensation cannot be so conceived, and that inconceivability is expressed directly by his definition's third condition.

Interpreting Newton's account: determined quantities of extension and the role of divine action

Yet what exactly are the ‘determined quantities of extension’ endowed with the three conditions that Newton asserts? The question is essential to an understanding of his account of body, but it also has implications for the nature and extent of divine providence, as we will see. It is often supposed that in his creation hypothesis, Newton takes God to create bodies from parts of absolute space itself. For example, Christopher Conn speaks of a body in De gravitatione as ‘nothing more than a divinely-modified region of space’.Footnote ²⁶ Geoffrey Gorham also takes Newton's determined quantities of extension to be parts of absolute space itself, contrasting the ‘favored regions of space’, which God endows with powers, against the ‘normal’ regions (though on his soft occasionalist interpretation, the favoured regions of space are given only powers of producing sensations).Footnote ²⁷ If Newton were seeking some sort of substrate in which properties could inhere, space might initially seem suitable, since as noted earlier, he considers it to be more like a substance than an accident. Nevertheless, there are powerful reasons to deny that he supposes God to create bodies by modifying parts of absolute space itself.Footnote ²⁸

The starting point of the creation hypothesis, though hardly decisive, is potentially significant. That starting point is the observation that we can make spaces impenetrable by moving our bodies into them – an action that does not, notably, alter the nature of space itself. Also significant, I think, is the ‘metaphysical truth’ that God ‘has created bodies in empty space out of nothing’;Footnote ²⁹ to square his account with that truth, as he means to do, Newton cannot say that God creates bodies out of space, since space is not nothing. A consideration that should be decisive, however, is the nature of space as he describes it, together with the implications of supposing that actual parts of space figure in his creation story and definition. He describes space as being eternal, immutable, immobile, unable to produce effects, and as having parts that are distinguishable but indivisible. To suppose that certain parts of space could be divinely modified, rendered able to produce sensations, solidified and set into motion, is to suppose a full contradiction of Newton's claims. It is to suppose that space is not eternal, because some parts of it may be turned into bodies; that space is not immutable, because some parts could be made impenetrable and able to produce sensations; and that its parts are not immobile and indivisible, because some parts, once made impenetrable, could be torn away from their neighbours and set into motion. And if some parts could be torn away, what exactly would ensue – would space be left with gaps, or would additional space appear to fill the gaps?

These are the sorts of conceptual problems that Newton points to when clarifying the first condition of his definition. Mobility is the first stated condition with which determined quantities of extension are endowed, and since space is immobile, he immediately clarifies that he is not speaking about the parts of space itself, but rather about their quantities: ‘therefore I did not say that they are numerical parts of space which are absolutely immobile, but only definite quantities which may be transferred from space to space.’Footnote ³⁰ Significantly, a quantity of some part of space is not identical to the part of space itself – after all, some numerically distinct parts of space have the same volume. Thus as Newton's own clarification indicates (a clarification we should keep firmly in mind when he seems to stray from it by employing more abbreviated locutionsFootnote ³¹), it is a mistake to reify his determined quantities of extension, by mistaking them for parts of space itself.Footnote ³²

Since Newton associates only quantities with the qualities or powers identified by his three conditions, and not parts of absolute space itself, bodies are constructed from powers alone. Insofar as it is useful to speak in terms of subject and the properties predicated of it, the quantity of any given region of space in which the powers are present may serve as a logical (grammatical) subject, but the utility of such locutions should not lead us to suppose that bodies consist in anything beyond powers. There is nothing like a substrate. Rather, bodies consist in sets of powers, distributed at multiple points of one region of space if the body is resting, or at points of successive regions if the body is moving. This interpretation does require that Newton's first condition, mobility, be considered differently from the other two, in that mobility must apply to something. I therefore suggest that Newton takes bodies (insofar as we can know them) to consist in mobile sets of spatially configured powers for mutual impenetrability and production of sensation. These mobile sets of powers must somehow be unified, so as to maintain their characteristic configurations as they either rest or move through space, and I propose that he assigns the task of unifying them to God. The powers are unified and maintained as enduring configurations by God – by y^e divine arm, to borrow a phrase that Newton uses elsewhere.Footnote ³³ The divine will accomplishes the task that he takes to be performed in the Aristotelian account by prime matter or substrate.

This interpretation fits well with his emphasis upon perceived qualities as the basis of a substance. In one of the explanatory points following his definition of body, he explains that the entities he has described are no less real than bodies and may be called substances, since ‘whatever reality we believe to be present in bodies is conferred on account of their phenomena and sensible qualities.’Footnote ³⁴ And a remark elsewhere in the manuscript, which I discuss in more detail in a subsequent section, points to attributes as the basis of ‘substantial reality’. An interesting implication of my interpretation is that the extension of bodies is parasitic upon the extension of space. Since bodies are extended in virtue of the presence of their constituent qualities or powers in space – a view whose conceptual predecessor is a concept of immaterial spirits as spatially located powers, as noted laterFootnote ³⁵ – only space is extended in the sense of having parts outside parts, a complete reversal of the Aristotelian view that all extension is corporeal, an attribute of matter.

An objection and response

Still, more needs to be said, because some of Newton's remarks may seem to conflict with the interpretation I have given. In an explanatory remark claiming an advantage for his own account over that of the Aristotelians, he writes, ‘Extension takes the place of the substantial subject in which the form of the body is conserved by the divine will.’Footnote ³⁶ This remark, which refers to extension itself, might make one wonder whether Newton does after all mean that God creates bodies by modifying regions of actual space.

I already noted a powerful reason to reject the view that this objection recommends, namely, that it conflicts with Newton's own concept of space and his own clarification that his definition refers to definite quantities, not to numerical parts of space. It should also be acknowledged that the mere mention of extension (space) cannot by itself imply anything, since the mobility condition ensures that absolute space must play some role in Newton's account and hence in any interpretation. Still, the remark figuring in the objection must be explained. To investigate Newton's meaning, then, I quote the remark in full, along with a second explanatory remark following his definition, which will help illuminate the one particularly at issue.

In both of these passages, Newton compares his account to the Aristotelian one, but the first passage repudiates the Aristotelian framework while the second points to a structural similarity between that account and his own.Footnote ³⁸ We will need to understand that structural similarity as well as the criticism in order to understand the remark figuring in the objection. Newton's criticism of the Aristotelian account, as elaborated elsewhere in the manuscript, is clear enough: its notions of prime matter or substrate (substantial subject, here) and of a substantial form inhering in that prime matter are unintelligible.Footnote ³⁹ This charge motivates the advantage he claims for his own account: since extension ‘takes the place of the substantial subject’, he avoids the unintelligible notion of prime matter.

Turning to the structural similarity, Newton takes extension (space) in his own account to be analogous to prime matter in the Aristotelian account; and he takes form in his account (which he also refers to as the product of the divine will) to be analogous to their substantial form. Before proceeding, we must ask what he could mean by ‘form’ in connection with his own account. I think he means ‘form’ to refer to the extent and shape of the configured set of powers. For in a limited class of cases, the Aristotelians take form to be little more than shape, and that is a use of the term that Newton can accept, even as he rejects the notion of substantial form more generally. Thus, when he writes that the form of the body is conserved by the divine will, he means that the spatial configuration of the set of powers is maintained by God's action, as I argued earlier.Footnote ⁴⁰

Proceeding, then, we next need to understand the relation Newton sees between prime matter and substantial form in the Aristotelian account, since that will enable us to understand the relation he asserts between extension and form in his own account.Footnote ⁴¹ He represents the Aristotelians as saying the following. Since prime matter can be associated with any form, its association with any body, via a particular form, is merely contingent; and so it is the substantial form that individuates the body.Footnote ⁴² That is to say, although prime matter facilitates a body's existence (since both prime matter and substantial form are needed for the body to exist), it never truly belongs to the body because its association with that body is contingent; and therefore, to refer to the body is actually to refer to its form.

Newton sees the same sort of relation in his own account, writing that ‘any form may be transferred through any space, and everywhere denote the same body.’ Space facilitates a body's existence, in that the body's powers must be distributed in space – for as noted earlier, no being can exist without being somehow related to space. Yet any given region of space may be associated with any body, since any body may occupy or pass through it; and since that region's association with the body (set of powers) is contingent, it cannot be said to belong to the body. This is Newton's point when he writes that the form denotes the same body, even as it is transferred through different spaces. Thus the interpretation that I have given can make sense of the passages discussed. (And it makes better sense of them than does the interpretation claiming bodies to be divinely modified parts of actual space. That interpretation cannot account for the contingent, transitory relation the passages assert to hold between a part of space and the form, for if a part of space were modified so as to become a body, its relation to the form would not be contingent or transitory.)

The account of body and the extent of God's providence

In another of the explanatory remarks following the definition of body, Newton states that the entities he has described subsist ‘through God alone’.Footnote ⁴³ The interpretation I have given provides a specific way of understanding this: the entities subsist through God alone in that the sets of powers are unified and maintained in their configurations by divine action. Since this action is direct, God's providence is much greater than if he merely concurred with the bodies’ continued existence. Still, Newton also leaves ample room for secondary causation, for as indicated earlier, he sees the account of body and thus God's direct action as limited to corpuscles. This suggests a view similar to that found in a much later text, Query 31 of the Opticks. Query 31 sidesteps the problem of cohesion at the sub-corpuscular level by suggesting that corpuscles are created by God, but it speculatively attributes the cohesion of aggregate bodies to interparticulate forces, and thus to secondary causes.Footnote ⁴⁴ Here too, by restricting his account of bodies to corpuscles, Newton leaves the cohesion of aggregate bodies to secondary causes.

The role that Newton assigns to God in De gravitatione therefore falls considerably short of occasionalism. This is consistent with the expectations that he evinces in other texts. In a letter of 1680, Newton writes: ‘Where natural causes are at hand God uses them as instruments in his works’.Footnote ⁴⁵ Furthermore, as I have argued elsewhere, Newton never endorses the hypothesis that God causes gravitational effects directly, and his continuous search for an explanation expresses his expectation of secondary causes.Footnote ⁴⁶

I therefore disagree with the interpretation defended recently by Gorham, who attributes occasionalism to Newton, albeit a soft sort.Footnote ⁴⁷ The occasionalism is soft in that God does not cause perceptions in minds directly, instead endowing varying regions of space with the power to do so, in a continuous creation of matter.Footnote ⁴⁸ Yet it is still a kind of occasionalism, because Gorham argues that the first and second conditions of Newton's definition of body are superfluous, doing ‘no independent work of their own’,Footnote ⁴⁹ and that bodies consist in only the powers to produce sensations. Regions of space are the ‘spatial occasions’ for the sensations, and God creates matter continuously by creating the powers to produce sensations in varying regions of space.Footnote ⁵⁰ Gorham claims a powerful advantage for his interpretation: it implies that Newton solves the mind–body problem, avoiding problems about mental causation ‘by embracing a quasi-idealistic ontology of matter’.Footnote ⁵¹ Yet his interpretation requires us not only to accept that conditions (1) and (2) of Newton's definition are superfluous, but also that condition (3), the power to produce perceptions in minds, is not merely necessary for body-hood but also sufficient. Gorham reaches this latter conclusion partly through his reading of the comment that Newton adds to this third condition – that it is not surprising that bodies have the power to cause perceptions in minds, ‘since the description of their origin is founded on this’.Footnote ⁵² Yet there is a natural reading of that remark which does not require either dismissing the definition's first two conditions as superfluous or supposing the third to be sufficient. That natural reading, which I explained earlier, is simply that if bodies lacked the power to produce sensations, we could never have any ideas of them. The remark is an instance of Newton's oft-repeated acknowledgement that we can know only perceived qualities, not the ‘essential and metaphysical constitution’ of things.Footnote ⁵³

Since I reject the occasionalist interpretation, I also reject Gorham's conclusion that ‘Newtonian bodies do not seem to qualify as self-standing substances’.Footnote ⁵⁴ On my interpretation, Newton considers bodies to be created substances. This is a desirable result, since bodies would have to be substances in order for Newton to accept a substantial distinction between mind and body – and he does, as we shall see in the next section.

Does Newton defend a substantial mind–body distinction? Two negative responses

Newton's discussion of mind contains an interesting fragment that one commentator interprets as a move towards substance monism. Concerning ideas of extension and thinking, the fragment reads, ‘the distinction between these ideas will not be so great but that both may fit the same created substance, that is, but that a body may think, and a thinking being extend.’Footnote ⁵⁷ The latter possibility, that thinking beings are extended, is not the interesting one, since Newton clearly asserts some sort of spatial extension of thinking beings, and that is compatible with a certain sort of substance dualism.Footnote ⁵⁸ The first possibility, however, ‘that a body may think’, calls to mind Locke's discussion of the possibility of thinking matterFootnote ⁵⁹ and Hobbes's overt materialism. One commentator, Liam Dempsey, interprets the fragment mentioning that possibility as a move toward monism.Footnote ⁶⁰

Dempsey's opening observation – that Newton does not take body to be the ‘metaphysical antithesis of mind’ – poses no threat to the claim that he accepts substance dualism.Footnote ⁶² It is rather the possibility that ‘a body may think’ that would conflict with dualism.Footnote ⁶³ The question to answer, therefore, is whether Dempsey is correct in taking Newton actually to endorse that possibility. Before turning to that question, however, we should note that Newton's commitment to the mind–body distinction has also been questioned on quite different grounds.

According to Howard Stein, it is not that Newton denies the distinction between mind and body; it is that he is simply uninterested in it.Footnote ⁶⁴ For Stein, focal statements include this cautionary remark, ‘It would be rash to say what may be the substantial basis of mind’,Footnote ⁶⁵ and especially Newton's comment, mentioned earlier, about attributes: ‘Substantial reality is to be ascribed to these kinds of attributes, which are real and intelligible things in themselves and do not need to be inherent in a subject.’Footnote ⁶⁶ In Stein's view, such remarks indicate that Newton is setting aside the question about dualism or monism, with respect to minds and bodies, in order to focus solely upon research questions about mental attributes and their relationship to corporeal attributes.Footnote ⁶⁷ Although Newton does suggest in another text that mental attributes may be investigated as internal phenomena, via the sense of reflection,Footnote ⁶⁸ Stein sees the ‘Newtonian Style’ in De gravitatione.Footnote ⁶⁹ He takes Newton to be restricting his gaze to empirically tractable questions alone.

Three truths of metaphysics

The remarks mentioned above, which might seem to cast doubt upon Newton's commitment to the substantial mind–body distinction, occur during the course of his attacks upon Descartes and upon the Scholastics. Throughout those attacks, his main goal is to show that his account of body is better able than either of those competitors to confirm three truths of metaphysics. Just before launching his attacks, then, he claims the advantage.

Thus Newton sees his account as confirming the following metaphysical truths. (1) God exists. (2) God has created bodies ex nihilo in empty space. (3) Minds and bodies are distinct, and specifically, there is a substantial distinction between them (as opposed to the mere distinction in reason that would be compatible with substance monism). The first truth, closely connected to the second, will number among Newton's desiderata for an account of substance; he holds that nothing dependent upon God could be truly understood independently of the deity, and will attack competitor accounts for implying that body could be understood independently of the deity and thus that they could actually be independent.Footnote ⁷¹

In light of Newton's explicit assertion that bodies ‘are beings distinct from created minds’, it would seem difficult to maintain either that he is indifferent to the substantial distinction, or that he is turning away from it in favour of monism. Still, there does seem to be some tension between that assertion and the remarks quoted earlier that the commentators find so telling. It will therefore be interesting to see whether closer inspection of those remarks might effect a reconciliation. Those remarks occur in connection with Newton's arguments that the Cartesian and the scholastic accounts cannot uphold the three truths of metaphysics. The fragment that caught Dempsey's attention will be considered directly. Although that discussion should refute not only Dempsey's conclusion about the substantial distinction but Stein's as well, Stein also suggests that Newton may be eliminating the concept of substance entirely; so I will reserve my discussion of the remarks that Stein focuses upon for a subsequent section, ‘Newton's reductive account of substance’.

Newton and the mind–body distinction

The fragment that led Dempsey to conclude that Newton is moving toward substance monism occurs during the course of his attack upon Descartes. Newton has already indicated that he thinks Descartes's account of matter compromises the first truth, by identifying matter with the one thing conceivable apart from God, space.Footnote ⁷² And trouble for the second truth follows; if space is eternal and can be conceived independently of God, then asserting that bodies are nothing more than regions of space undercuts the claim that God created them ex nihilo. The passage containing the fragment continues the attack by arguing that Descartes's view forces him into the horns of a dilemma, in which he must abandon either the second truth of metaphysics or else the third. Newton's charge implicitly relies upon a tenet that he accepts, namely, that whatever God creates is eminently contained within him; and he then uses Descartes's claim that the ideas of thinking and extension are mutually repugnant against him.

The first horn of the dilemma is the theologically intolerable claim that bodies were not created by God. This is set out in the extended sentence that opens the passage, with Newton reasoning as follows. Descartes seeks a ‘complete’ distinction between minds and bodies, according to which only bodies are spatially extended. But if extension cannot be associated with thinking things, then it cannot be eminently contained within God.Footnote ⁷⁴ Further, if extension is not eminently contained in God, and if, as Descartes holds, body is nothing more than extension, then since everything that God creates is eminently contained within him, body is not divinely created. So Cartesian body is elevated to being a substance in the same, absolute sense that God is substance, in violation of the second truth of metaphysics.

The second horn of the dilemma, set out in the long, second sentence of the passage above, contains the fragment at issue. This horn of the dilemma is the admission that minds and bodies are not distinct in the sense of sharing no properties whatsoever – which for Descartes would imply that they are not substantially distinct. Newton reasons as follows. If Descartes wants to avoid the first horn of the dilemma, so as to preserve the truth that God created bodies ex nihilo, he can do that only by agreeing that extension is eminently contained in God. But if Descartes agrees to that, it follows that ‘the idea of extension will be eminently contained within the idea of thinking’ – and that contradicts his claim that the ideas of extension and thinking are mutually repugnant, which is the very basis of his dualism. Thus if Descartes tries to avoid the dilemma's first horn, he will be forced into the second horn, violating the third truth of metaphysics by admitting both the possibility ‘that a body may think’ and the possibility that ‘a thinking being extend’.

Thus Newton is not endorsing the possibility of thinking matter, as Dempsey thought, but is rather trying to show how Descartes can be driven to admit that possibility.Footnote ⁷⁵ Contrary to Dempsey's conclusion, then, Newton is not advancing towards monism. The fragment and the surrounding remarks are fully consistent with Newton's earlier advocacy of the third truth of metaphysics, and thus with some manner of substance dualism. The dualist reading is reinforced by other remarks, not least this: ‘Created mind (since it is in the image of God) is of a far more noble nature than body.’Footnote ⁷⁶ In light of Newton's commitment to a substantial mind–body distinction – and his reliance upon such non-empirical concepts as eminent containment – Stein's claim that Newton is uninterested in the distinction can now be rejected, along with Dempsey's monism. Yet the remarks that caught Stein's attention remain puzzling. I will address them in the next section, since they pertain not only to mind but also to God and to substance generally.

Attributes, substantial reality, and the question about eliminativism

The context of Newton's remark about substantial reality, which indicates his positive view, is his attack upon the Scholastics’ account of body, for he sees their notion of substance as the source of their troubles, notably their inability to confirm the three truths of metaphysics. They cannot confirm the third truth, he reasons, because they suppose an ‘unintelligible reality that they call substance’ to reside in bodies, and yet distinguishing the substance of mind from the substance of body requires that the latter be intelligible.Footnote ⁷⁷ Yet more to the point here are the first and second truths of metaphysics.

According to Newton, the correct account of created substance will imply the deity's existence, because anything that could not exist without God cannot be conceived without God. Created substances are intermediate between accidents and God – intermediate in their degree of dependence and hence their ‘degree of reality’, since they sustain accidents yet are themselves sustained by God. In particular, bodies have only a ‘derivative and incomplete reality’, not the absolute, independent reality properly ascribed only to God. Newton's own account, as we have seen, implies the deity's existence by defining bodies in terms of the perception-stimulating qualities that cannot be conceived apart from God. But the scholastic account of bodies fails to imply their created, dependent state. This is because it relies upon the notion of bare substance, which, as a property-less thing, is a ‘subject which we cannot conceive as dependent’.Footnote ⁷⁸ The charge can be expressed in terms of two traditional concepts of substance, the first being the Scholastics' concept, that which is a subject of inherence, and the second being that which is self-subsistent. Newton charges that by employing that first concept, the Scholastics fail to classify substances correctly according to the second concept; whereas an account should imply that God alone is fully self-subsistent, their account improperly implies that bodies are as well.

Here we arrive at the remark in question. It will be useful to consider it together with some comments that follow.

In the opening sentence, Newton indicates that substantial reality – self-subsistence – can be ascribed to certain attributes. He next suggests that space, which he clearly denied is a substance, is an attribute, and one having some substantial reality. He then proceeds to attribute full substantial reality to God's power to create, suggesting that the deity might be conceived in terms of an attribute alone; and he closes the passage by expressing ignorance about the mind's substantial basis.

Is Newton suggesting here that the very concept of substance should be eliminated? Stein seems to draw that conclusion with respect to God. He first notes, ‘Newton goes so far as to suggest that even God might be conceived entirely in terms of his attributes, if only we could form clear “Ideas” of these.’ Stein then infers that Newton rejected the Trinity because he rejected the concept of substance altogether: ‘the view of substantial reality described here would make not so much false, as entirely unintelligible, the proposition that God is “three persons, but one substance”!’Footnote ⁸⁰ Eliminativism simply does not fit, however, with Newton's claims throughout the manuscript. For one thing, he considers the entities of his creation story and associated definition to be substances, as we saw earlier, asserting that they are no less real than bodies, ‘nor (I say) are they less able to be called substances’.Footnote ⁸¹ Additionally, he asserts a substantial distinction between mind and body, as we saw in the previous section, and that distinction implies the concept of substance. Finally, we should note Newton's criticism of the scholastic account of body: ‘The same word, substance,’ he writes, ‘is applied univocally in the schools to God and his creatures.’Footnote ⁸² Implicit in this criticism is an acceptance of the distinction between the strong and weak concepts of substance, and thus of the concept of substance itself.

A reductive account of substance

Since Newton accepts the concept of substance, it seems that by ascribing substantial reality to attributes, he is giving a reductive account of it, by identifying a substance with its characteristic attributes. This is not immediately evident, perhaps, since he devotes part of his discussion to something that he already denied is a substance, space. Space is implied to be an attribute, in the passage, though this is consistent with his earlier claim that it is an affection of every kind of being, not an accident in a subject. Interestingly, even though space is not a substance, it has more substantial reality than the created substances, as indicated by its being independently intelligible. Yet this is consistent with Newton's claim that space has its own manner of existing, and it makes sense of the attention he devotes to it. From the passage as a whole, we can extract his reductive account of substance.

Newton's position is clearest in the case of the divine substance. God's power has full substantial reality, and so only that attribute is fully self-subsistent. The divine power to create is thus a substance, and the only substance in the strong sense. There must of course be a caveat: this is a concept of the substance insofar as we can know it, for as he indicated earlier, we do not know the ‘essential and metaphysical constitution’ of things.Footnote ⁸³ This was so in the account of body, and it is all the more true of God, since we are not capable of formulating a clear idea of the divine power. Nevertheless, Newton indicates, we would recognize the power as self-subsistent, ‘if we should form an idea of that attribute’; in other words, we recognize that the power is self-subsistent, even though we do not understand how it is so. Thus in Newton's view, the divine substance just is the power to create. He is certainly not the first to embrace such a reductive concept, which identifies God with attributes. Precedents for that reach back to the medieval nominalists, and also include Descartes, who identifies substances generally with their attributes, which must themselves be identical to one another.Footnote ⁸⁴ Although Newton does not mention other divine attributes, such as omniscience, his view presumably includes the belief that God is identical to that attribute, which is in turn identical to omnipotence and creative power. But space is not among the attributes identical to the divine substance. If space were identical to God, it would be difficult to account for Newton's claim that space is the one thing conceivable apart from God.Footnote ⁸⁵ Even more significantly, space is not a substance, as Newton unequivocally stated earlier and implies anew in the above-quoted passage. Space is not absolute in itself, whereas God, the one being that is fully self-subsistent, the one substance in the strong sense, is absolute in himself. Moreover, space does not act, whereas God acts, by creating and sustaining the world. Thus space is an effect of God, as Newton indicated earlier; it is neither a divine attribute nor God himself.Footnote ⁸⁶

Turning to the mind, there is compelling reason to think that Newton means to identify this created substance too with attributes, even though his remarks are spare. At the end of the passage, he indicates that we do not know the mind's substantial basis (substantiale fundamentum), since we do not understand the ‘proper power’ by which it moves the body. Here his point seems to be that to understand an entity's substantial nature is to understand its characteristic attribute or power.Footnote ⁸⁷ A contrast is implied to the case of body, in which we can associate its characteristic attribute, impenetrability, with a tendency to be reflected in a law-governed way. We lack such knowledge about the mind, and if the substance just is the attribute, then failing to understand the mind's power to move the body is to fail to understand its substance.Footnote ⁸⁸ Still, much as Newton thinks we know that God's power is self-subsistent, without knowing how, we also know that the mind consists in this power, though we cannot explain how it works. So though our knowledge of the mind is incomplete, we can claim to know something about it, namely, that it is present in space; that it is immaterial, being substantially distinct from body; and according to my interpretation, that its weakly independent substantial existence consists in certain powers, present in space. This reductive account of the mind agrees with his reductive account of the divine substance. He has identified God with a power, and he has also said that mind, which is nobler than body, is created in ‘the image of God’.Footnote ⁸⁹

My reason for preferring Stein's term for the account of body, ‘creation hypothesis’, over Slowik's term, ‘determined quantities of extension hypothesis’, should now be clear: the latter term does not apply to bodies alone, but may also be applied to minds, since minds too are powers present in space. Minds do not have parts outside parts, but instead are spatially located and extended in virtue of the presence of their constituent powers in space, the one thing that does have parts outside parts. The space in which the mind's powers are present will presumably be the same as that in which the body's powers are distributed, since Newton takes the mind's spatial location to make its union with the body intelligible and possible.Footnote ⁹⁰ One question remains. If both minds and bodies consist in powers present in space, such that they equally lack parts outside parts, how are we to understand the distinction that Newton draws between them? He distinguishes them clearly, remarking that ‘any being has a manner proper to itself of being present in spaces’. Continuing, he compares the presence of a moment of duration and of a mind in space to one another, while contrasting them to body: just as a moment of duration is ‘diffused throughout all spaces … without any concept of parts’, so a mind ‘can be diffused through space without any concept of its parts’.Footnote ⁹¹ While this certainly seems to imply that bodies do have parts outside parts, it may refer to our phenomenal experience of them. We experience bodies as having parts outside parts, because of their impenetrability powers. Moreover, those powers differ from the powers comprising immaterial substances, both in the effects they produce and in their domain. Each power belonging to a body might correspond to only a single point in space; yet the power comprising a spirit may be a unity, even as it is present in multiple points of space.