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Is Kant's Realm of Ends a Unum
per Se? Aquinas, Suárez, Leibniz
and Kant on Composition
Lucas Thorpe a
a Philosophy Department, Boğaziçi University
Version of record first published: 10 Jun 2010.
To cite this article: Lucas Thorpe (2010): Is Kant's Realm of Ends a Unum per Se?
Aquinas, Suárez, Leibniz and Kant on Composition, British Journal for the History of
Philosophy, 18:3, 461-485
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ARTICLE
ISKANT’SREALM OF ENDS A UNUM PER SE?
AQUINAS,SUA
´REZ,LEIBNIZ AND KANT ON
COMPOSITION
Lucas Thorpe
Kant and Leibniz are interested in explaining how a number of individuals
can come together and form a single unified composite substance. Leibniz
does not have a convincing account of how this is possible. In his pre-critical
writings and in his later metaphysics lectures, Kant is committed to the
claim that the idea of a world is the idea of a real whole, and hence is the
idea of a composite substance. This metaphysical idea is taken over into his
ethical writings and becomes the idea of a realm of ends. I explain why a
realm of ends, should be thought of as both a unum per se and as a real
whole. A realm of ends is a whole of individuals unified by laws they have
given themselves, that is, it is a community of autonomous individuals. Only
such a community can be thought of as a composite individual. Such a
whole will be real rather than ideal because the source of the unity of the
whole is intrinsic to the whole, for what gives unity to the realm are laws and
the sources of the laws are the individual members of the whole. It will be a
unum per se because both the laws and the individuals constituting the realm
are incomplete without one another. If this reading is correct, this requires a
fundamental reevaluation of Kant’s notion of autonomy. To be autono-
mous is not, primarily, to be understood in terms of ruling oneself, but
instead must be thought of primarily in terms of being a generative source of
laws for an ideal community.
[N]o moral principle is based, as people sometimes suppose, on any feeling
whatsoever. Any such principle is really an obscurely thought metaphysics that
is inherent in every human being because of his rational predisposition, as a
teacher will readily grant if he experiments in questioning his pupil socratically
about the imperative of duty and its application to moral appraisal of his
actions. The way the teacher presents this (his technique) should not always be
metaphysical, nor his terms scholastic, unless he wants to train his pupil as a
philosopher, but his thought must go all the way back to the elements of
metaphysics, without which no certitude or purity can be expected in the
doctrine of virtue, nor indeed any moving force (Metaphysics of Morals, 6:
376, my emphasis).
British Journal for the History of Philosophy 18(3) 2010: 461–485
British Journal for the History of Philosophy
ISSN 0960-8788 print/ISSN 1469-3526 online ª2010 BSHP
http://www.informaworld.com DOI: 10.1080/09608781003779800
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INTRODUCTION
In this paper I argue that Kant’s idea of a realm of ends is not essentially an
ethical idea, but a theoretical one – namely, the idea of a community of
individuals, an idea to which Kant refers in his theoretical works as the idea
of a world, or the intelligible world. The development of this idea was
originally part of Kant’s monadology and meant to solve a theoretical
problem that Leibniz was unable to solve. Kant began his philosophical
career as an unorthodox Leibnizian, and he spent much of the 1750s and
1760s trying to develop a monadology. Unlike Leibniz, Kant was committed
to the position that monads can really interact, and he believed that any
adequate monadology must be able to explain how a set of monads could
constitute a ‘world’ in a meaningful sense. In particular, like many
eighteenth-century German metaphysicians, he believed that the idea of a
world is the idea of a composite and so any adequate monadology must be
able to explain the possibility of monadic composition, a possibility that
Leibniz was unable to explain.
The problem of monadic composition, for both Leibniz and Kant, had
been to explain how a number of independent individuals can come together
and form one thing. For both of them, this is a metaphysical problem.
Ultimately, Leibniz was unable to explain how a substantial composite was
possible and bequeathed this problem to Kant. Kant’s solution to Leibniz’
problem of composition was inspired by Rousseau. A set of independent
individuals can form a true substantial composite only if each member of the
composite is responsible for the laws that provide the composite with its
unity. In other words, in a substantial composite, each member of the
composite must be autonomous. Kant names our idea of such a composite
substance an intelligible world or a realm of ends (Reich der Zwecke).
1
It
should be clear that I am here advocating a particular conception of
autonomy that differs from the standard understanding in a number of
respects. First, the idea of autonomy is originally a theoretical and not a
practical/ethical notion. Second, to be autonomous on this interpretation is
not primarily to give law to oneself, but rather for oneself to generate laws
for a possible ideal community. Such laws bind all, and only bind oneself as
a member of the community. An autonomous individual, then, does not
merely ‘give laws to herself’, such an individual generates laws for all, and
only as part of the all are the laws binding on the individual giving them.
What is important in the ‘auto’ in autonomous is that the laws are from the
self, not to the self. Those (and I believe that the majority of Kant scholars
are guilty of this) who identify autonomy merely with a kind of ‘sovereignty’
1
This identification of the idea of a realm of ends with the idea of an intelligible world is a
central claim of this paper and textual support will be provided later in the paper.
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over oneself miss this point.
2
Finally, the primary meaning of ‘autonomy’ is
substantial, not adverbial. Most readers of Kant take the adverbial sense as
primary, in that they think that being autonomous has to be understood
primarily in terms of how one acts. If I am right, being autonomous has to
do primarily not with how we act, but with what we are. The adverbial sense
of autonomy is secondary, and determined by the substantial sense. We have
the idea of an autonomous being, namely the idea an individual that is the
source of laws for a community, and to be autonomous is to instantiate this
idea.
Although in the 1750s and 1760s, Kant, like Leibniz, had believed that the
purpose of metaphysical speculation was to provide us with a true account
of the way the world actually is, altogether independently of us, over time
his attitude to metaphysical speculation diverged from that of Leibniz. He
came to see that such speculation cannot give us insight into the way things
are, altogether independently of us. However, although such metaphysical
speculation cannot provide us with any knowledge of the way the world is in
itself, it can provide us with an ‘image’ of the way the world could and
should be.
3
The idea of a world of individuals in interaction (the idea of a
realm of ends) is not a possible object of or faculty of intuition (and as a
result, is not a possible object of cognition), it is, however, a possible object
of our faculty of desire; that is, it is a possible object of choice, for we can
choose to be a member of such a world.
4
Kant’s account of how this idea can be a possible object of choice is rather
complicated. The idea a member of an intelligible world is the idea of an
autonomous individual, that is, the idea of an individual that is the source of
the laws that provide the world with its unity. To choose to be a member of
such a world, then, is to choose to instantiate this idea. However, the
possibility of such a choice presupposes that we have the capacity to give
such laws and that we have a reliable way of realizing this capacity. We have
no theoretical reason to assume that we have such a strange capacity, but we
2
See Richard Tuck, The Rights of War and Peace: Political Thought and the International Order
from Grotius to Kant, Oxford University Press (1999) for an interesting discussion of the
relationship between the ideas of sovereignty and autonomy.
3
For more on this point, see Lucas Thorpe, ‘According to Kant, What’s the Point of Studying
Ethics?’, Journal of Value Inquiry, 2006.
4
In Kant’s language, the idea of a world of monads cannot be an object of our faculty of
cognition (the faculty examined in the Critique of Pure Reason), but it can be an object of the
faculty of desire (the faculty examined in the Critique of Practical Reason). To make the idea of
an intelligible world the object of our faculty of desire is to make the choice that such a world
actually exists, for to claim that it is possible to make this idea an object of our faculty of desire
is, by definition, to claim that we can be the cause of the object of the idea; for ‘the faculty of
desire is the faculty to be, by means of one’s representations, the cause of the objects of these
representations’ (Metaphysics of Morals, 6: 211). If it is possible for us to make the idea of being
a member of an intelligible world the object of our faculty of desire, then, by definition, by
means of this representation (idea) of a member of an intelligible world, we can be the cause of
the object of this idea.
AQUINAS, SUA
´REZ, LEIBNIZ AND KANT ON COMPOSITION 463
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also have no theoretical reason to deny it. Morally, however, in so far as the
idea of being a member of a world presents itself to us as the good, we must
assume that we have such a capacity and some way of realizing it. Therefore,
we have a sufficient practical reason to assume the existence of this capacity.
Through introspection, the only possible candidate for such a capacity is our
conscience and our disposition to experience the feeling of respect, so we
must make the assumption that if we really listen to our conscience, the
moral law will come pouring out via the spontaneously generative powers of
this capacity, and we will instantiate the idea of being an autonomous
individual.
This paper has two main sections. In the first section I examine Leibniz’
problem in accounting for monadic composition. I begin by explaining
the problem and then look at a number of unsuccessful attempts Leibniz
makes to provide a solution, focusing on one particular attempt to offer a
solution, namely, Leibniz’s appeal to the notion of a vinculum substantiale
in his correspondence with Des Bosses. In this correspondence Leibniz
suggests that we can understand real composition in terms of a
substantial chain superadded by God. The reason I focus on this account
is because, although he never uses this language, Kant believes that
something like a vinculum substantiale, or the intrinsic structure of a real
whole, is necessary to explain the possibility of composite substances. In
his metaphysics lectures, Kant calls this something a nexus realis, and I
believe that in his writings on the foundations of natural science, this
becomes the notion of a natural law and in his ethical writings, it
becomes the notion of moral law. Thus, my claim is that Kant replaces
Leibniz’ notion of a vinculum substantiale with that of natural or moral
law and believes that in order for this to provide real unity, it must be
either cognized (in the case of natural law) or willed (in the case of moral
law) by a rational human member of the world rather than being
superadded by God.
In the second section I examine Kant’s engagement with the problem and
argue that Kant’s idea of a realm of ends should be thought of as offering a
solution to Leibniz’ problem.
In the course of my discussion, I distinguish between two senses of unity:
the scholastic notion of unity per se (which is contrasted with unity per
accidens) and Kant’s notion of real unity (which is contrasted with ideal
unity). I will argue that the idea of a kingdom of ends satisfies the
requirement for both real unity and unity per se. Before turning to Leibniz
and Kant, I will briefly explain these two senses of unity.
REAL UNITY AND UNITY PER SE
I will now distinguish between two senses of unity, namely, between the
scholastic notion of a unum per se (contrasted with a unum per accidens) and
464 LUCAS THORPE
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the Kantian notion of real unity (contrasted with ideal unity). The
scholastics distinguished between a unum per se and a unum per accidens,
with an individual material substance being a unum per se consisting of both
form and matter. There seem to be two essential elements in two things
forming a unum per se. First, the two things must be incomplete without the
other, and second the relation between them must be immediate. Leibniz
often uses this scholastic language, but often contrasts unum per se not with
aunum per accidens but with unum per aggregationem.
5
It is not clear
whether his understanding corresponds to the scholastic one.
Kant, in his metaphysics lectures, frequently distinguishes between real
unity and ideal unity.
6
Kant, like Leibniz, is not particularly transparent
about what is involved in real as opposed to ideal unity, but I suggest that
the best way of understanding this distinction is in terms of a distinction
between ‘intrinsic’ and ‘extrinsic’ unity. In something that is intrinsically
unified, the ground of the unity is to be found in the thing possessing the
unity, whereas in an extrinsic unity the ground of the unity is external to the
thing unified.
The scholastic notion of a unum per se is stronger than the Kantian notion
of real unity. A unum per se has real unity,
7
but something that has real unity
may not have to be a unum per se in Leibniz’ (or Kant’s) sense. I will argue
that both Leibniz and Kant believe that real unity, as opposed to unity per se
(in the scholastic sense), is the type of unity required for something to be a
composite substance.
For the scholastics, a unum per se is composed of both form and matter.
Thus, for example, the human being is a composite being, consisting of both
form (the soul) and matter (the body). Leibniz seems to accept this aspect of
the scholastic definition of unity per se. Thus, for example, in De mundo
praesenti (1784–6) he explains,
Every real entity is either a unity in itself, or an accidental entity. An entity
(unity)in itself is, for instance, a man: and accidental entity (unity) – for
example, a woodpile, a machine – is what is only a unity by aggregation . . . in
an entity per se some real union is required, consisting not in the situation and
5
See, for example, the correspondence with Des Bosses (GPII, 506)
6
Leibniz distinguishes between real unity and (mere) phenomenal unity, and perhaps this maps
onto Kant’s distinction. Leibniz also sometimes talks of metaphysical unity. Brandon Look
argues for a strong distinction between ‘metaphysical unity’ and ‘real unity’. I am not so
convinced by this distinction and am not clear about what he thinks is involved in the
distinction, so I will ignore this possible distinction in this paper. See Look, ‘Leibniz and the
‘‘Vinculum Substantiale’’’, Studia Leibnitiana Sonderhefte #30 (Franz Steiner Verlag Stuttgart,
1999) 55–63.
7
I think the reason for this is that for the scholastics, matter and form are intrinsic properties,
and I have defined a ‘real unity’ as something that has intrinsic as opposed to extrinsic unity. As
Des Chene explains: ‘Of the four Aristotelian causes, two – the material and formal – are
intrinsic, since they are parts of the thing of which they are causes, while the other two – the
efficient and final – are extrinsic’ (128).
AQUINAS, SUA
´REZ, LEIBNIZ AND KANT ON COMPOSITION 465
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motion of parts, as in a chain, a house, or a ship, but in some unique individual
principle and subject of its attributes and operations, which in us is called a
soul, and in every body a substantial form, provided the body is a unity in
itself.
8
This composite is a unum per se, because (a) both soul and body are, in some
sense, incomplete without each other, and (b) the relation between soul and
body is immediate. I will focus exclusively on this first condition of unity per
se, and I will focus on the account of Sua
´rez.
Sua
´rez argues that form and matter are really distinct in that they can
exist independently of each other through the will of God. In other words,
there is no logical contradiction in the notion of formless matter or
matterless form.
9
Form and matter together constitute a unum per se,
however, because they are naturally dependent upon one another, and are
naturally incomplete without the other. Thus, Sua
´rez writes that,
since matter and form per se are not complete, whole beings in their kind, but
are instituted by their nature to be composed into [a substantial nature], that
[nature], which is composed immediately from them, is deservedly called, and
is, a nature and essence which is one per se.
10
A number of further points about the scholastic notion of a unum per se
ought to be mentioned: first, there were disagreements about whether the
form and matter themselves were independent substances, capable of
independent existence. It was thought by some that in the case of most
composite substances, the form (called ‘the material form’) was incapable of
existing without the matter.
11
At least in the case of human beings, however,
it was generally agreed that the form (the intellectual soul) was capable of
8
G. W. Leibniz: The Labyrinth of the Continuum, edited and translated by R. Arthur (New
Haven: Yale University Press, 2001) 283. Similarly, in Definitiones notionum atque logicarum
(1685?), Leibniz explains that, ‘the ancient philosophers rightly attributed substantial forms,
such as minds, and souls or primary entelechies, to those things which they said make a unum
per se, and denied that matter per se is one entity’. Ibid., 271.
9
As we shall see, Aquinas will deny this, arguing that the idea of formless matter is
contradictory.
10
Sua
´rez, Disp.4x3{8, Opera 25: 127–8. Quoted from Des Chene, 135.
11
Although this is denied by Sua
´rez who argues that,
Aristotle and [other] philosophers perhaps could deny that [material forms] can in any
way subsist separately from matter, because they judged that dependence and actual
inherence in matter are essential to them. But we Catholics, who believe that God
conserves accidents without their subjects, cannot doubt that (although certain
moderns do) that God could also conserve substantial material forms without matter,
since the dependence of an accident on its subject [ .. . ] is greater’ than that of a
substantial form on matter.
(Sua
´rez, Disp.15x9{1, Opera 25: 532.)
Quoted from Des Chene, 124.
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existing without the body.
12
This fact is the source of a serious problem with
Brandon Look’s criticism of Leibniz’ vinculum substantiale. Look argues
that the vinculum substantiale must either be a form or a substance and
assumes without arguement that it cannot be both, thus ruling out without
arguement a fairly standard scholastic position, namely that the human soul
was both a form and a substance.
13
With regard to matter, there was some
disagreement between different scholastic writers. Aquinas seems to hold
that matter cannot exist without form (either naturally or supernaturally)
14
,
and Sua
´rez, for example, holds that matter can exist without form.
15
Second, the scholastics clearly need to provide a more detailed account of
the way in which matter and form are incomplete. Given the belief that the
human soul (form) could exist independently from the body, this
incompleteness could not be explained in terms of being incapable of
existing apart from one another. Instead, as Des Chene explains, ‘matter, as
pure potentia, and form as the actus substantialis of matter are ‘ordered first
of all to each other’.
16
It is not clear, however, how we are to cash this out.
In the case of a realm of ends, in contrast, there is a quite natural way of
understanding how the form and matter are incomplete without one
another. In a realm of ends (or ‘world’), the matter is the individuals making
12
Thus, in the course of his discussion of the soul in the Summa Theologica, Aquinas explains
that, ‘nothing can intrinsically act unless it intrinsically subsists, since things act in the same way
that they exist. We conclude therefore that the human soul, which we call the intellect or mind is
something immaterial and subsistent’ (1, 75, 2, 61) and he continues by explaining that, ‘nothing
subsistent can come to be or pass away incidentally, that is when something else has come to be
or passed away’ (1, 75, 6, 63). In contrast to the human soul,
non subsistent things (e.g. accidents and material forms) can come to be and pass
away by the coming-to-be and the passing away of composites. The souls of irrational
animals are not intrinsically subsistent, and so those souls pass away when irrational
animals’ bodies pass away. But human souls are intrinsically subsistent and so they
could not pass away.
(1, 75, 6, 63–4)
These passages should make it clear that Aquinas believed that a form may, or may not, be a
substance. Translations are from Aquinas: A Summary of his Philosophy, translated and edited
by Richard J. Regan (Hackett, 2003).
13
‘Leibniz and the ‘‘Vinculum Substantiale’’’, Studia Leibnitiana Sonderhefte #30 (Stuttgart:
Franz Steiner Verlag, 1999).
14
As Des Chene explains,
[t]he Thomists argued that matter without form would be actu sine actu, which is
openly contradictory. Soncinas, citing Averroes, writes that ‘matter differs from form
but is never denuded of form, and indeed when it is separated from one form, it takes
on another, since if it were denuded of all forms, what is not in actu would be in actu’.
(Soncinas Q. meta. 8q1resp., 180b; Averroes In Phys.
2c2comm12, Opera 4: 52G. Des Chene, 126)
15
The position of Sua
´rez is that although, ‘matter can exist without form, according to God’s
absolute power; matter cannot naturally exist without form’ (Des Chene, 126). It is this natural
dependence that is meant to explain the way in which form and matter are incomplete without
each other.
16
Des Chenne, 135.
AQUINAS, SUA
´REZ, LEIBNIZ AND KANT ON COMPOSITION 467
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up the world and the form is the laws which provide the world with the unity
that it has. The law and the individual members of the world are logically or
analytically distinct, because it is logically consistent that individuals can
exist without the law and also that the law exists independently from the
individuals. The individuals are, nevertheless, morally incomplete without
the law (and they are incomplete individually not merely collectively)
and the law is incomplete if it is not actually realized in a community.
Therefore, the complementarity between the law and the individuals in a
real whole is non-logically or synthetically a priori necessary. Otherwise put,
a real whole is a synthetically a priori necessitated whole.
1. LEIBNIZ
(a) The Problem
It is well known that Leibniz believes that everything that really exists must
be one, in the sense of being essentially unified. He also, however, seems
committed to the possibility of composite substances.
17
Many of Leibniz’
contemporaries were committed to the coherence of the notion of composite
substance, because they believed that a human being is such a substance,
being a substantial union, consisting of both mind and body. Of particular
concern to Leibniz, and his contemporaries, then, was the attempt to give an
account of the union of mind and body.
18
There are also texts that suggest
that Leibniz believed that a world must also be a substantial composite.
19
Even if Leibniz himself was not committed to this view, we shall see that a
17
It is important to distinguish the question of whether of not Leibniz believes in the existence of
composite substances from the question of whether he regards matter (body in general) as
phenomenal. It is quite consistent to claim that body is phenomenal (as the mature Leibniz
does) but that animals really are composite substances. For Leibniz, or at least for the mature
Leibniz, this second question is no longer a question about the relationship between two distinct
types of substance (mind and body) but the relationship between a single monad and a
multitude of monads, for a mind is a monad, and a body is an infinite collection of monads (that
is confusedly perceived to be one). In providing the monads that constitute its body with unity,
the mind and these monads come to constitute an organism (or living being). Thus, Leibniz
writes that ‘the body belonging to the monad that is its entelechy or soul constitutes with this
entelechy what might be called an organism 5i.e. living being4, and with a soul what is called
an animal’ (Monadology # 63).
18
As we shall see, there are disagreements as to whether Leibniz actually believed in the
existence of composite substance. As early as 1685, Leibniz could claim that, ‘no entity that is
truly one [ens vere unum] is composed of parts. Every substance is indivisible and whatever
has pars is not an entity but a phenomenon’, Defintitiones notionum metaphysicarum atque
logicarum (1685?). Quoted from R. C. Sleigh, Leibniz and Arnauld (Yale University Press,
1990) 124.
19
In a reply to Bayle, written in 1702, Leibniz writes that,
not all entelechies are, like our soul, images of God; for they are not all intended to be
members of a society or a state of which he is the head. But they are still images of the
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number of his followers (and critics) in eighteenth-century Germany, such as
Baumgarten, Meier and Crusius, were committed to this position, and Kant,
following their lead, took it as part of the definition of a world that it must
be a real composite.
The postulation of composite substances, however, presents Leibniz
with a problem, for it is not clear how, given his own account of the
nature of substance, something composite can really be an individual. It
is not clear in what sense a composite of Leibnizian monads can be
essentially unified.
Leibniz’ most common account of the unity of a (mind) monad and the
monads that make up its body is to argue that a mind is ‘dominant’ over
these other monads and that it is this relation of dominance that constitutes
the (unifying) relation between the mind and (the monads that constitute)
the body. Leibniz, however, seems to deny the existence of real relations
between monads, and so this dominance can only be explained in terms of
the harmony between individuals.
At least up until the late 1690s, Leibniz seems to have believed that the
union between a mind and the monads that constitute its body could be
accounted for in terms of the harmony that existed between them. Thus, in
his New System of the Nature and Communication of Substances, and of the
Union of Soul and Body of 1695, Leibniz expounds his account of the nature
of individual substances, and argues that,
There will be a perfect agreement among all of these substances, producing
the same effect that would be noticed if they communicated through the
transmission of species or qualities, as the common philosophers imagine
they do. In addition, the organized mass, in which the point of view of the
soul lies, being expressed more closely by the soul, is in turn ready to act
by itself, following the law of the corporeal machine, at the moment when
the soul wills it to act; without disturbing the laws of the other – the spirits
and blood then having exactly the motions that they need to respond to the
passions and perceptions of the soul. It is this mutual relation, regulated in
advance in each substance of the universe, which produces what we call their
communication, and which alone brings about the union of soul and body.
20
universe. They are in their own way scaled down worlds: fertile simplicities;unities of
substance, though, because of the multitude of their modifications, virtually infinite,
which express an infinite circumference.
(Leibniz’s ‘New System’ and Associated Contemporary Texts, translated by
R. S. Woolhouse and Richard Francs (Oxford University Press, 1997) 116)
A few pages later, he adds that for the soul not God, ‘it is enough for it to be a little world’
(118). The idea that the soul is like a world (and vice versa) suggests that Leibniz thinks that a
world has the same sort of unity as a soul.
20
Ariew and Garber (1989) 143–4, my emphasis.
AQUINAS, SUA
´REZ, LEIBNIZ AND KANT ON COMPOSITION 469
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Here, then, Leibniz argues that the unity of mind and body can be explained
in terms of the harmony between them. However, as Rene
´Joseph de
Tournemine pointed out in his Conjectures on the Union of the Soul and the
Body, a work not unsympathetic to Leibniz and written in response to his
New System, pre-established harmony does not seem strong enough to
account for the union between mind and body. De Tournemine begins his
article with a recounting of Leibniz’s attack upon Descartes and the
occasionalists. The Cartesians, de Tournemine argues, will tell you that,
the soul and the body . . . are united because to each change in the body there
corresponds a change in the soul, and in the same way to each change in the
soul there corresponds a change in the body.
21
Tournemine praises Leibniz for pointing out that the mere correspondence
between changes in the mind and changes in the body is not sufficient to
account for real unity. He argues, however, that Leibniz’ own position is
subject to similar criticisms. Thus, he argues that Leibniz,
makes against the Cartesians an objection which entirely destroys their theory
of the union of the soul and the body. Neither the law which God lays down
for himself to act in parallel on the soul and on the body, nor the
correspondence between the changes in the one and the changes in the other,
can produce any genuine union between the soul and the body. There is, if you
like, a perfect correspondence; but there is no real connection, any more than
there would be between two clocks [the motions of which are perfectly
matched]. There is no answer to this objection; but unfortunately, it destroys
M. Leibniz’s theory as well as that of the Cartesians. For after all,
correspondence,orharmony, does not make a union, or essential connection.
Whatever parallels we imagine between two clocks, even if the relation
between them were perfectly exact, we could never say that these clocks were
united just because the movements of the one corresponded to the movements
of the other with perfect symmetry.
22
Leibniz himself accepts this criticism, and in a commentary on de
Tournemine’s article he recognizes that,
I have to admit that I would be greatly mistaken if I objected against the
Cartesians that the agreement which, according to them, God maintains
immediately between the soul and the body, does not create a genuine unity,
because most certainly my pre-established harmony could not do any better.
23
21
Woolhouse (1997) 247.
22
Woolhouse (1997) 248–9, my emphasis.
23
Woolhouse (1997) 250.
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Leibniz continues by suggesting that in offering his theory of pre-established
harmony, he ‘attempted only to give an explanation of the phenomena, that
is to say, of the relation we perceive between the soul and the body’ (ibid.).
The metaphysical union between mind and body, however, is not
phenomenal, and so Leibniz claims that he has ‘not taken it upon [himself]
to look for an explanation of it’ (ibid.). Leibniz’ reaction here seems pretty
disingenuous, for it seems clear that Leibniz’ monadology, of which his
doctrine of pre-established harmony is an essential component, is clearly
more than an attempt to ‘explain the phenomena’.
Leibniz seems to have taken Tournemine’s criticism on board, for
although Leibniz argues in the Monadology that all monads are, in some
sense, embodied, he seems to have accepted that pre-established harmony
cannot really account for true unity between mind and body. Thus, he
argues that,
these principles have given me a way to explain naturally the union, or rather
the conformity of the soul and the organic body. The soul follows its own laws
and the body likewise follows its own; and they agree by virtue of the pre-
established harmony among all substances.
24
(Monadology #78, my emphasis)
Here, Leibniz seems to accept that, strictly speaking, the relationship
between monads in an organism is something less than union. Passages such
as these have led many commentators to conclude that Leibniz’ mature view
is that, strictly speaking, there are no composite substances. Thus,
Rutherford argues that ‘the most reliable texts come down firmly on the
side of monads alone, with real union and composite substance rejected’.
25
24
He also refers to his discussion with Tournemine in his correspondence with Des Bosses,
explaining that,
I do not deny some real metaphysical union between the soul and the organic body,
according to which it can be said that the soul is truly in the body; I have also said this
in reply to Tournemine. But because such a thing cannot be explained by the
phenomena and changes nothing in them, I cannot explain any more distinctly of what
this union formally consists. It is enough that it is tied up with the correspondence.
You will understand, moreover, that I have been speaking so far, not of the union of
the entelechy or active principle with primary matter or passive power, but of the
union of the soul or of the monad itself (which is the result of both these principles)
with the mass or with other monads.
(Leibniz to Des Bosses, 30 April 30 1709. GII, 369–72, Loemker, 972)
25
Leibniz and the Rational Order of Nature, Donald Rutherford (Cambridge University Press,
1995) 281. A similar position is advocated by Adams who argues that (even in the so-called
middle years) corporeal substances, ‘are reducible to simple substances or monads, related in
certain ways’ (R. M. Adams, Leibniz, Determinist, Theist, Idealist, (Oxford University Press,
1994) 242). Rauzy summarizes the dominant reading in a recent article: ‘most commentators
agree that when Leibniz speaks of ‘corporeal substances’, he is ultimately referring only to soul-
like substantial forms’ (Jean Baptiste Rauzy, ‘Leibniz on Body Force and Extension’
Proceedings of the Aristotelian Society, CV, (2005) Pt 3: 363–84, esp. 366). Such a view has
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(b) Leibniz’s Vinculum Substantiale
It seems that Leibniz has at least four strategies he sometimes uses, or at
least toys with, for attempting to deal with this problem. The first strategy
(1) involves appealing to the form/matter distinction and arguing that
composite substances are a composite of form and matter in the scholastic
sense. There are at least two versions of this strategy. The first (a) involves
treating the dominant monad as the form and the subordinate monads as
the matter. Such an account can be extrapolated from the correspondence
with Arnauld. The second (b) involves treating all the monads (the
dominant and subordinate) as the matter and arguing that the substantial
form is some additional thing. This seems to be the position Leibniz defends
in his correspondence with Des Bosses where he introduces the idea of a
substantial bond (vinculum substantiale) that is superadded by God and
which seems to function analogously to a scholastic substantial form in
providing a set of monads with real unity.
26
The second strategy, (2), is that
Leibniz does not really deny the reality of relations and the real
relations between monads can account for unity of the composite
been forcefully challenged by Daniel Garber, who argues that in his ‘middle years’ (c.1685–
c.1695) Leibniz was committed to the reality of composite corporeal substances. Thus, Garber
argues that in his middle years, Leibniz ‘does feel the need to recognize in bodies something over
and above the immaterial substances he calls forms, something from which extension can arise’
(D. Garber ‘Leibniz and the foundations of Physics: The Middle Years’ in The Natural
Philosophy of Leibniz, edited by K. Okruhlik and J. R. Brown (Dordrecht: Reidel, 1985) 27–
130). More recently, Phemister has argued that Leibniz remained committed to the reality of
composite corporeal substances until the end of his life, arguing that,
Leibniz considered bodies to be rather more that the results of the aggregation of
unextended and indivisible monads: that he regarded them also as aggregates of
corporeal substances. Corporeal substances are living creatures, having both a soul (or
something similar) and an extended body.
(Pauline Phemister, ‘Leibniz and the Elements of Compound Bodies’,
British Journal for the History of Philosophy (1999) 57–78)
26
Leibniz also seems to offer a third account of the way in which composite substances can be
thought of as composites consisting of matter and form and matter, which is to identify the
form of a body with its primitive acting force and the matter of a body with its primitive passive
force. Thus, he writes in a note dated to the mid 1680s that,
Corporeal substances have parts and species. The parts are matter and form. Matter is
the principle of passion, or primitive force of resisting, which is commonly called bulk
or antitypy, from which flows the impenetrability of body. Substantial form is the
principle of action, or primitive force of acting.
((A 6.4.1508), quote from Daniel Garber, ‘Leibniz on Body, Matter and
Extension’, Aristotelian Society Supplementary, LXXVIII (2004) 34)
Garber notes that ‘it is not at all clear how to reconcile [this view of matter] with the conception
of matter as the organic body of a corporeal substance’ (35). This view would seem to be
applicable to all bodies, including tables and chairs, and not just living beings. Ultimately, as
Garber notes, we have to ask about the ontological status of primitive passive force. At least by
the time of the Monadology, Leibniz seems committed to the view that this can be explained in
terms of (and reduced to) monads and their states.
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substance.
27
The third strategy, (3), involves an appeal to God’s scientia
visionis.
28
Finally, (4), one can solve the problem by having Leibniz
argue that there is no need for composite substances. I believe that given his
other ontological commitments, Leibniz has no compelling philosophical
reasons to be committed to the existence of organisms as composite
27
When Rutherford argues that Leibniz denies the existence of composite substances in Leibniz’
mature ontology, he adds that, ‘this is exactly what we should expect given his deep and abiding
commitment to the ideality of relations’. The standard reading of Leibniz is that all relations
between substances are reducible to properties of the individuals and are, therefore, ultimately
ideal. However, although Leibniz denies the possibility of real interaction between monads, it is
not absolutely clear that he denies all real relations. For example, Leibniz believes that monads
possess knowledge of the states of other monads; one might think that this could be used to
ground some sort of real relations, for, although he thinks that perception cannot be explained
in terms of causal influence, he does argue that monadic perception is a form of knowledge, and
it would seem that knowledge is either a type, or perhaps a ground, of real relation. Thus,
Leibniz writes in 1695 that ‘I am also far from willing to admit that the soul ‘does not know
bodies, even though this knowledge arises without any influence of the one on the other’
(Leibniz’s ‘New System’ and Associated Contemporary Texts, translated by R. S. Woolhouse and
Richard Francs (Oxford University Press, 1997) 49.) If ‘knowing’ is a real relation, Leibniz
might be able to use it in an account of the unity of composite substances.
28
See Donald Rutherford, ‘Leibniz and the Problem of Monadic Aggregation’, Archiv fu
¨r
Geschichte der Philosophie, 76 (1994): 65–90. Look, in contrast, argues that Leibniz’ appeal to
God’s scientia visionis is not intended to play the part of an account of the unity of composite
substances, but is merely meant to explain their reality, as it applies to all phenomenal objects
(tables, chairs, cabbages and kings), some of which Leibniz believes are not composite
substances, and so the scientia visionis cannot, and is not intended to, explain the real unity of
organic beings. Thus, he writes that ‘‘‘scientia visionis’’ applies to all bodies, including composite
substances’, Look, 12. He argues that the appeal to God’s scientia visionis is not meant to
explain the unity of phenomenal objects, but merely their reality. Thus, he explains that
there are two issues here that have not been properly delineated; namely, the
explanation of the unity of composite substances and the explanation of the reality of
composite substances. Scientia Visionis provides us only with a guarantee of the
‘reality’ of composite substances, and this is done primarily on an epistemological
level: while phenomena (of composite substances) may appear differently to different
observers, there is a sense in which there is a ‘fact of the matter’; and this ‘fact of the
matter’ concerning substances is known by God.
(Look, 115)
This distinction between explaining ‘reality’ and ‘unity’ ultimately does not seem to be useful,
for what Leibniz needs in his explanation of the unity of composite substances is an adequate
account of the reality of such unity, so if Leibniz’s theory of scientia visionis is able to offer an
adequate account of the reality of phenomenal substance, part of this account should have to do
with the reality of the unity of such substances. God’s scientia visionis is supposed to ground the
reality of the relations between monads, and the relations between monads in an organic body
are different from the relations in a non-organic body. Therefore, it seems to me that this
criticism is not successful. If God’s scientia visionis can explain reality, it could be used to
explain how cabbages and kings have real unity while tables and chairs do not. The real
problem as I see it, which as we shall see was also Kant’s major worry, is how to guarantee the
reality (as opposed to ideality) of the unity of composites, and if the scientia visionis can really
explain the reality of the relations between monads, then it can do this. The problem, as Kant
suggests and with which I agree, is that the unity provided by God’s scientia visionis can only be
ideal and not real.
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substances and so personally was attracted by the fourth strategy.
However, many of his contemporaries were strongly committed to the
existence of organisms and so he recognized that in order to make his
position as appealing as possible to as wide an audience as possible, it
would be expedient to offer some sort of account of how his monadology
was compatible with the real existence of organisms. In addition, and
perhaps more problematically for his philosophy as a whole, without some
sort of account of the possibility of monadic composition, he cannot explain
what it is that makes a world aworld.
29
Many of his German followers in the
eighteenth century, including Kant, believed that a world must be a unified
composite in a strong sense. For Kant, the material parts of the whole must be
intrinsically nomologically structured. Leibniz himself seemed to be less
worried about this than he should have been, for it seems that his whole
theory of possible worlds rests upon being able to make sense of the idea of a
possible world. If Leibniz cannot give a convincing account of the nature of
monadic composition, it is difficult to explain what it is that makes a possible
world aworld.
In this paper I will focus on one particular strategy (1b), which is
Leibniz’s suggestion in his correspondence with Des Bosses that a
composite substance is a composite of form and matter, with the matter
being the monads making up the substance and the form being a
‘substantial chain’ (vinculum substantiale) which is superadded by God. In
this correspondence, Leibniz introduces the idea of a vinculum substantiale
(substantial chain or bond). There are disagreements among scholars as to
why he introduces this notion. The traditional reading is that Leibniz was
motivated, as Russell puts it, purely by an anxiety, ‘to persuade Catholics
that they might, without heresy, believe in his doctrine of monads’.
30
29
Indeed, if Leibniz believed that the world was infinite, then he was explicitly committed to the
fact that it was not a unity. Thus, in Deum non esse mundi animam, he explains that
if it is assumed that the world is infinite, it is not one being, i.e. a body one in itself
(unum per se corpus) . . . Therefore, no soul can be understood as belonging to it.
Certainly, an infinite world is no more one and whole than infinite number, which
Galileo demonstrated is neither one nor whole.
He makes a similar point in De mundo praesenti where he explains that ‘the aggregate of all
bodies is called the world, which if it is infinite, is not even one entity, any more than an infinite
straight line or the greatest number are’. Both quoted from Gregory Brown, ‘Leibniz’s
Mathematical Argument against a Soul of the World’, British Journal for the History of
Philosophy, 13 (2005) No. 3: 450. This article contains an interesting discussion of this issue,
although the title is misleading, for what Leibniz wishes to prove is not that the world cannot
have a soul, but merely that God cannot be the soul of the world. Leibniz’ argument is that if
the world if infinite, it cannot have a soul because it cannot be a real unity, but that if it is finite,
God could not be its soul. Although Leibniz is committed to the infinitude of monads (i.e. to the
claim that the world is infinite in multitude), he is not necessarily committed to the belief that
the world is infinite in magnitude.
30
Bertrand Russell, The Philosophy of Leibniz (Routledge, 1992) 152. Russell continues by
claiming, ‘(t)hus the vinculum substantiale is rather the concession of a diplomatist than the
creed of a philosopher’.
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In contrast to Russell, I take Leibniz’ suggestion of the vinculum substantiale
seriously, not necessarily because I believe that Leibniz ultimately saw it as
anything more than an ad hoc attempt to persuade a Jesuit that his
monadological theory was compatible with the Catholic doctrine of
transubstantiation (although I think he probably did take it more seriously
than this), but because I believe that, although he never uses this language,
Kant believes that something like a vinculum substantiale is necessary to
explain the possibility of substantial composition. As we shall see, in his
metaphysics lectures Kant calls this something a nexus realis, and I suggest
that in his ethical writings this is replaced by the notion of law. Thus, my claim
is that Kant replaces Leibniz’ notion of a vinculum substantiale with that of an
intrinsically structuring law and believes that in order for this to provide real
unity, it must be cognized or willed by every rational human member of the
world rather than being superadded by God.
According to Leibniz, the vinculum substantiale is something over and
above the monads that compose a composite substance:
The peripatetics as a whole recognize something substantial besides monads;
otherwise they would have no substances besides monads. Monads do not
constitute a complete composite substance, since they do not make up a unity
per se but merely an aggregate, unless some substantial chain [vinculum
substantiale] is added.
31
This vinculum substantiale must be superadded by God:
The unity of corporeal substance in a horse does not arise from any ‘refraction’
of monads but from as superadded substantial chain [vinculum substantiale]
through which nothing else is changed in the monads themselves.
32
One of the points of contention between Leibniz and Des Bosses was over
the nature of such a chain, with Leibniz arguing that it must be substantial
and Des Bosses arguing that it would have to be accidental. Des Bosses
defines an accident as, ‘whatever in itself presupposes a complete substance,
so that it cannot naturally exist without this substance’.
33
Leibniz, in what
31
Leibniz to Des Bosses, 26 May 1712. GII, 444. Loemker, 980.
32
Leibniz to Des Bosses, 16 June 1712. GII, 450–2. Loemker, 984.
33
My emphasis. Here is the paragraph in which this explanation occurs:
It remains for us to accept something absolute in which the reification of phenomena
consists [i.e. a vinculum substantiale]. This you call a substance, I an accident; but I
believes we are not in disagreement about the matter itself.I call an accident whatever
in itself presupposes a complete substance, so that it cannot naturally exist without this
substance. And this absolute unifier presupposes complete substances or the monads,
without which it cannot exist naturally. For according to you ‘monads are in fact
ingredients of this added being’.
(Des Bosses to Leibniz, 20 May 1712. GII 441–2. Loemker 978–9. My emphasis)
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we shall see is a standard scholastic position, rejects this definition as too
broad, believing that it locates the distinction between substances and
accidents at the wrong place. Substances are really distinct whereas a
substance and an accident are not, and the criterion for real distinctness is
not whether two things can naturally exist apart from one another, but
whether they can be separated by God – which can be done if there is no
logical contradiction in the things existing apart from one another. Thus,
the scholastics accepted that the human soul is something substantial
although it cannot naturally exist without a body, although it can so exist
through an act of divine will (i.e. it is logically possible for the human soul
to exist without a body and so it could be made to exist without body).
Kant is able to get between this opposition between the merely natural or
a posteriori impossibility of mind–body separation and the logical
possibility of mind–body separation by holding that the mental and the
physical are at once synthetically a priori necessarily connected and also
logically or analytically distinct, hence really complementary yet irreducibly
different kinds of property.
It seems to me that given his commitments, Leibniz has no way to
explain how a composite substance can be a unum per se in this sense, for
it would seem contradictory to say that monads are incomplete without
the vinculum substantiale. Indeed, Leibniz seems to insist on this every
time he stresses that the vinculum substantiale must be superadded by
God. It seems to me that if xneeds to be superadded to y, then xis (or
at least can be) complete without y.
At the start of the paragraph in the letter to Des Bosses I cited above, in
which Leibniz claims that the vinculum substantiale must be superadded by
God, Leibniz writes that
I believe that monads always have full existence and that we cannot
conceive of parts being said to be potentially in the whole. Nor do I see
what a dominant monad would detract from the existence of other
monads, since there is really no intercourse between them but merely an
agreement.
34
The problem is that for two things to form a unum per se,theyhavetobe(a)
logically or analytically distinct
35
and also (b) in some metaphysically real sense
incomplete without each other. Leibniz has absolutely no problem with the first
condition, but it seems to me that he has no way of explaining the second
condition.
36
34
Leibniz to Des Bosses, 16 June 1712. GII, 450–2. Loemker, 984.
35
In that logically, if not naturally, it is possible for one of them to exist without the other.
36
Also, I do not see how he could say that such a composite is a real as opposed to an ideal unity
in Kant’s sense, for the fact that the unifying principle must be superadded implies that
ultimately, the source of the unity is extrinsic to the things unified. Kant, I believe, attempts to
offer a solution to this problem. A composite substance will be a real (as opposed to an ideal)
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2. KANT
My discussion of Kant is divided into four sections. I begin (a) by briefly
comparing Kant’s notion of a nexus realis with Leibniz’s vinculum
substantiale. I then (b) take a more detailed look at Kant’s account of the
idea of an intelligible world in his metaphysics lectures. Next, (c), I suggest
that in a realm of ends the (moral) law should be regarded at the form
whereas the (law-generating) members of the world should be thought of as
the matter. The form (¼law) and the matter (¼rational human law-
generating individuals) are complementary proper parts of the same real
whole. As such I suggest that a realm of ends can be thought of as being
both a real unity and a unum per se. Finally, (d), I distinguish between the
way in which the law is the form of the realm of ends for Kant and the way
in which the intellectual soul is the form of the human body for Aquinas.
I believe that there is something plausible behind Kant’s position. If I am
right, then at the heart of Kant’s ethics is the idea that being moral involves
really interacting with others, and that such interaction is possible only if the
individuals interacting are the source of the laws that make the interaction
possible. One could, thus, quite plausibly call Kant’s ethics an ethics of
interaction, for if I am right, being virtuous ultimately comes down to
striving to really interact with others. I think that the best way of bringing
this out is by making an analogy with a conversation.
There are two plausible assumptions about communication. The first is
that two individuals can communicate only if they speak the same language,
and the second is the Davidsonian suggestion that language does not exist
prior to, or independently of, individual speech acts or speakers.
37
If these
assumptions are correct, then in order to communicate, both speakers have
to generate the same language through their individual utterances. This idea
of two individuals speaking the same language is an ideal, and an ideal that
probably can never be instantiated, but it can be approached and
approximated; that is, I am suggesting that even if, as Davidson suggests,
there is no such thing as language, this does not imply that ‘speaking the
same language’ cannot be our criterion for successful communication, or
trying to speak the same language our criterion for genuinely trying to
unity if the members of the composite are responsible for the unity of the whole and it will be a
unum per se if the individuals composing the composite are (individually and not merely
collectively) incomplete without the form. I will argue that this will be the case in the Realm of
Ends, for in such a realm (a) the individual members of the realm ‘give’ the laws which provide
the real with its unity, and (b) individuals who do not ‘give law’ are (morally) incomplete.
37
Davidson famously claims that ‘I conclude that there is no such thing as language, not if a
language is anything like what many philosophers and linguists have supposed. There is
therefore no such thing to be learned, mastered, or born with’ (107). ‘A Nice Derangement of
Epitaphs’ in Donald Davidson, Truth, Language, and History (Oxford University Press, 2005).
See also, ‘The Social Aspect of Language’, ibid., 109–25. My suggestion is that, when it comes
to language, the fact that there is no such thing to be learned or mastered does not imply that
there is no such thing to be approached.
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communicate. Analogously, really interacting, for Kant, involves being an
autonomous member of a world each member of which is a source of the
same laws that govern the whole world. The fact that a world governed by
laws given by all might be an impossible ideal does not mean that being a
member of such a world cannot be our criterion for real interaction and
striving to be a member of such a world cannot be our criterion for
genuinely trying to interact with others, for although such a world might be
impossible to realize, we can approach it asymptotically, just as someone
who believes that there is no such thing as language might think that
successful communication involves the idiolects of the individual speakers
converging on one another, with the ideal being a single idiolect or language.
Such a model captures very well the way that sincere conversations actually
work. Very often, when engaged in a conversation, misunderstandings occur
and much of the work in such conversations involves trying to overcome
these misunderstandings, and this can be understood in terms of trying to
ensure that we are both speaking the same language as the process of trying
to make our idiolects converge. The idea of a community of individuals
‘giving the same laws’ can be thought of in similar terms.
(a) Kant’s Vinculum Substantiale
Although in discussion of the question of the possibility of composite
substances, Leibniz was particularly concerned with the question of organic
animals, we have also seen that there is some textual evidence to suggest that
he believed that a world must be a substantial composite as well. At the very
least, many of his followers (and critics) in eighteenth-century Germany,
such as Baumgarten, Meier and Crusius,
38
were committed to this position,
and, as I will show, Kant, following their lead, took it as part of the
definition of a world that it must be a real composite.
39
In the cosmology sections of his metaphysics lectures, Kant always begins
by claiming that a world (or our idea of a world) must be a real unity and
must consist of (a) a matter (the individuals that make up the world) and (b)
a form, which Kant calls a ‘nexus realis’. I suggest that Kant’s nexus realis
plays the same function as Leibniz’ vinculum substantiale. Kant’s account,
38
For a good discussion of this, see Eric Watkins, Kant and the Metaphysics of Causality
(Cambridge University Press, 2005) esp. 85–9.
39
I think that one reason Kant was committed to the idea that the world must be thought
of as a composite substance is that this makes it impossible for me to think of myself as a
world:
If the world is a connection 5nexus4of substances, then I cannot think of the world
egoistically, i.e. I cannot say: I am the world . . . For since a world requires many
substances and yet in addition a connection 5nexum4of them, then I as a single
substance cannot constitute a world.
(Metaphysik Mrongovius, 29: 852)
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however, is far more successful than Leibniz’ in explaining monadic
composition.
I want to argue that Kant’s account of ‘a world’ in his metaphysics
lectures should be identified with the ethical ideal of a realm of ends, and
believe the idea of a realm of ends did not originally emerge as an ethical
idea, but rather, as a way of explaining a problem in Leibniz’
metaphysics. Later, in the critical period, Kant came to realize that
metaphysics itself has an ethical foundation – nothing can be metaphy-
sically real that makes autonomy impossible. This is one deep implication
of what he means by ‘the primacy of practical reason over theoretical
reason’ in the Groundwork and the Critique of Practical Reason. The idea
of a realm of ends is the idea of a community of autonomous individuals,
that is, a world of individuals (monads) each of which is responsible for
giving the laws that provide the community with its unity. I suggest that
such a community will have real unity in Kant’s sense and be a unum per
se in the scholastic sense. The matter of such a community will be the
individual members of the community, the form of such a community
will be the laws that provide the community with its unity. In a realm of
ends (or ‘world’), the matter is the individuals making up the world and
the form is the laws which provide the world with the unity it has. The
law and the individual members of the world are logically or analytically
distinct, because individuals can consistently exist without the law and
the law exists independently from the individuals.
40
The individuals are,
nevertheless, synthetically a priori necessarily morally incomplete without
the law (and they are incomplete individually, not merely collectively) and
the law is synthetically a priori necessarily incomplete if it is not actually
realized in a community.
There are two significant (and interconnected) differences between
Kant’s account and Leibniz’: (a) the individual members of a composite
substance have to be the source of the vinculum substantiale rather than
God, and (b) the individual members of the composite have in some
metaphysically real sense to be incomplete without the addition of the
vinculum substantiale. The first condition is necessary if the composite is
to be a real unity; the second condition is necessary if the composite is to
be unum per se.
40
It is, I believe, to guarantee this second condition that Kant often stresses that we must think
of the law as a command of God. Kant does not say this because he agrees with natural law
theorists such as Aquinas that the moral law gets its force from the will of God; rather; he
stresses this because it is important to him the law be thought of as, in some sense, independent
of human individuals. By using the scholastic notion of a unum per se, I am trying to suggest
why the independence of the law might have been important to Kant. He is committed to the
idea that the law of a community is logically or analytically but not really distinct from the
individuals who make up a community.
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(b) Kant’s Discussion of the Idea of a World in his Metaphysics Lectures
For Kant, our idea of a world is the idea of a substantial composite and, like
the scholastics, he is committed to the idea that such a composite must be
composed of a matter and a form.
41
He makes his commitment to the idea
of the world as the idea of a substantial composite in the cosmology sections
of his metaphysics lectures. The first point he makes is that our idea of a
world is the idea of a whole. Thus, he argues that ‘[a] multitude of
substances without connection makes no world. One must thus not define
world: the universe of substances, but rather the whole of them’ (Metaphysik
Dohna, 28: 657). However, he also argues that to constitute a world,
substances they must form what he calls a real as opposed to an ideal whole.
Kant believes that any composite must have both a form and a matter,
and hence there are two conditions that distinguish a real from an ideal
whole, a material condition and a formal condition: (1) the material
condition for existence of a real whole is that the parts of a real whole must
be true individuals. This condition, which Kant sometimes characterizes in
terms of saying that the world must be a substantial whole, implies, Kant
believes, that spatial wholes, for example, are merely ideal wholes.
42
This
material condition for real wholeness is a major motivation for Kant’s claim
that space is ideal. We also find similar claims in Leibniz.
43
(2) The formal
condition is that the unity of the whole must be ‘real’ rather than ‘ideal’ and
41
Kant calls our idea of a world ‘the intelligible world’. Kant makes this clear in the Critique of
Pure Reason where he claims that ‘The mundus intelligibilis is nothing but the concept of a world
in general, abstracting from all [i.e. spatio-temporal] conditions of intuiting it’ (A433/B461, my
addition in square brackets). He makes a similar point in his metaphysics lectures from the same
period when he claims that,
a foreigner called it fantasy to speak of the intelligible world 5mundo intelligibili4.
But this is just the opposite, for one understands by it not another world, but rather
this world as I think of it through the understanding.
(Metaphysik Mrongovius, 29: 850, my emphasis)
42
The world is thus a substantial whole 5totum substantiale4, hence not merely ideal.
We can think of diverse ideal wholes 5tota idealia4, but they do not constitute a
world, e.g. I can represent to myself a syllogistic whole 5totum syllogismorum4,an
accidental whole 5totum accidentale4, or a whole in space, etc.; but these are mere
ideal wholes 5tota idealia4, which consist of concepts. But the world is a real whole
5totum reale4, which consists of concepts.
(Metaphysic Mrongovius, 29: 851)
43
Thus, in a letter to Dangicout written shortly before his death, Leibniz writes that,
Intellectual wholes have parts only potentially . . . It is like unity in Arithmetic which
is also an intellectual or ideal whole divisible into parts, such as into fractions for
example, not actually in itself, otherwise it would be reducible into minimal parts
which are not to be found in numbers, so as to produce assigned fractions. I therefore
say that matter which is something actual is a result only of monads by which I mean
simple, indivisible substances, but extension or geometrical magnitude is not
composed of possible parts that can only be assigned there, nor is it resoluble into
points, and points too are only extremities and must not be taken for parts or
components of the line.
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the guarantee of the reality of the unity is the existence of ‘real’
connection(s).
What is most significant here is his account of this formal condition, for
when we are talking of a world of monads, it is assumed that the material
condition is met, for the matter of the world is the individuals that make up
the world. In explaining this condition, he writes that, ‘Substances are the
matter of the world, the formal aspect of the world consists in their
connection 5nexu4and indeed in a real connection 5nexu reali4. The
world is thus a real whole 5totum reale4, not ideal’ (Metaphysik L2. 28:
581). Our idea of a world is the idea of a real as opposed to an ideal whole in
this sense.
44
Elsewhere, Kant is a bit more explicit about this distinction. He
argues that,
The connection 5nexus4is ideal if I merely think the substances together,
and real if the substances actually stand in interaction 5commercio4. // The
form of the world is a real connection 5nexus realis4because it is a real
whole 5totum reale4. For if we have a multitude of substances, then these
must also stand together in a connection, otherwise they would be isolated.
Isolated substances, however, never constitute a whole 5totum4, then they
must also be a real whole 5totum reale4. For were they ideal, then surely
they could be represented in thought as a whole 5totum4,orthe
representations of them would constitute a whole 5totum4; but things in
themselves would still not constitute a whole on this account.
(Metaphysik Mrongovius, 29: 851)
An ideal whole is a whole that can be ‘represented in thought’ as a whole. In
such a whole, the unity exists only in the mind of the observer (or perhaps,
as a weaker transcendental constraint, is necessarily cognizable by a possible
rational human observer). In a real whole, in contrast, the unity must be
intrinsic to the whole. Although Kant himself does not explicitly make this
claim, I suggest that what this means is that the individuals that constitute
(Quoted from Jean-Baptiste Rauzy, ‘Leibniz on Body, Force and Extension’,
Proceedings of the Aristotelian Society, CV (1995) Pt 3: 382)
44
He frequently makes similar points. For example, elsewhere he claims that,
The aggregation of the substances in which there is no community still does not
constitute a world. Reciprocal determination, the form of the world as a composite
5compositi4, rests upon interaction 5commercio4.If we thought substances without
real connection 5absque nexu reali4and without interaction 5commercium4, where
every substance would be in and for itself and they would have no community with one
another, then that would indeed be a multitude 5multitude4, but still not a world. //
Thus the connection 5nexus4of substances that stand in interaction 5commercio4
is the essential condition of the world.
(Metaphysik L2, 28:196, my emphasis)
Elsewhere, he explains that the world as a composite must consist of form and matter and that
while the ‘material of the world are substances’, the formal element ‘is the real connection 5nexus
realis4of these substances. Real connection is reciprocal influence (acting and suffering) . . . a
multitude of substances without connection makes no world’ (Metaphysik Dohna, 28: 657).
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the whole must be both individually and collectively responsible for the
unity of the whole. If we believe that what supplies unity to a whole are laws,
then a real whole will be one in which the individuals that make up the
whole are the source of the laws that provide the whole with its unity; that is,
a real whole will be a realm of ends and the only way of being a member of
such a whole is to be an autonomous being (that is, a being that is the
generator of the laws that provides the whole with its unity.) As we shall see
in the following section, it seems that Kant is explicitly trying to make such
an argument in the Groundwork.
(c) Kant’s Realm of Ends as Both a Real Unity and a Unum Per Se
In the Groundwork, Kant explains that, ‘[b]y a realm I understand a
systematic union of various rational beings through common laws . . . what
these laws have as their purpose is just the relation of these beings to one
another as ends and means’ (4: 434) Here, Kant makes it clear that the
purpose of laws in a realm of ends is to provide the ‘glue’ that gives a
community of individuals some sort of unity. He continues by explaining
that the only way to be a member of such a community is through being
autonomous, that is by being (individually) the source of the laws that
provide the community with its unity. Thus, he explains that ‘a rational
being belongs as a member to the realm of ends when he gives universal laws
in it but is also himself subject to these laws’ (4: 434). Here, Kant seems to be
quite explicit about the fact that being autonomous is the membership
condition for belonging to a realm of ends. I have suggested that the best
way of making sense of this claim is in terms of the argument, given in the
previous section, that a world of intelligible beings can have real unity only
if the rational individuals that are members of the world are both
individually and collectively the generative source of the laws that provide
the world with its unity. Kant seems to be quite clear about this a few pages
later, where he argues that ‘in this way a world of rational beings (mundus
intelligibilis) as a realm of ends is possible, through the giving of their own
laws by all persons as members’ (4: 438). Here, Kant makes it quite clear
that it is the generating of laws by the rational members of a world that
makes the world possible.
45
45
I believe that Kant tries to make a similar point in the Critique of Practical Reason, although
here he is not so clear. For example, he argues that,
supersensible nature . . . is nothing other than a nature under the autonomy of pure
practical reason. The law of this autonomy, however, is the moral law, which is
therefore the fundamental law of a supersensible nature and of a pure world of the
understanding.
(5: 43)
He seems to repeat, or at least allude to the idea that autonomy is a condition for the possibility
of an intelligible world. For example, he argues that, ‘[t]he moral law is, in fact, a law of the
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In addition to being a real whole in Kant’s sense, a case can be made for
claiming that a realm of ends would also be a unum per se in the scholastic
sense. If we remember, Suarez explains that,
since matter and form per se are not complete, whole beings in their kind, but
are instituted by their nature to be composed into [a substantial nature], that
[nature], which is composed immediately from them, is deservedly called, and
is, a nature and essence which is one per se.
46
The idea of a realm of ends is the idea of a community of independent
individuals (monads) unified bylaws they have given themselves. The laws will
be the intrinsic structuring form of the community and the independent
individuals will be the causally efficacious matter. For this community to be a
unum per se, both the law and the individuals have to be, in some metaphysically
real sense, incomplete without each other. As we saw in the discussion of
Leibniz, the big problem he has in explaining monadic composition is that
monads are totally independent of each other and it is difficult to see in what
sense they could possiblybe incomplete without the vinculum substantiale.Kant
can be thought of as offering a solution to this problem, for on his
understanding of a realm of ends, both the form and matter are synthetically
a priori necessarily incomplete without each other. The laws can be thought of
as synthetically a priori necessarily incomplete if they remain unwilled and do
not actually govern particular individuals. The individuals, even though
independent and essentially active, are also synthetically a priori necessarily
incomplete without the moral law. The moral law is an intrinsic structure of
our volition in autonomous action. Willing the moral law completes us in a
moral sense. Both the form (the moral laws) and the matter (the individual
members of a realm of ends) are incomplete without one another, and thus a
realm of ends should be thought of as a unum per se in the scholastic sense.
47
causality through freedom and hence a law of the possibility of a supersensible nature’ (5: 43)
and that ‘Freedom considered positively’ can be defined as, ‘the causality of a being insofar as
it belongs to the intelligible world’ (5: 132).
46
Sua
´rez, Disp.4x3{8, Opera 25: 127–8. Quoted from Des Chene, 135.
47
Another way of putting this is in terms of Flathman’s distinction between ‘high-liberal’ and
‘low-liberal’ interpretations of citizenship. Beiner (forthcoming) discusses whether or not Kant
has a ‘high’ or ‘low’ liberal conception of citizenship and my claim that individuals must be
considered incomplete in so far as they do not ‘give law’ would suggest a ‘high liberal’
reading. Another way of making this point would be to claim that we are completed as
individuals by becoming citizens in a realm of ends. See Richard E. Flathman, ‘Citizenship
and Authority: A Chastened View of Citizenship,’ in Theorizing Citizenship, edited by R.
Beiner (Albany, NY: State University of New York Press, 1995) 105–51. As Beiner explains
the high liberal position,
According to what I’m calling the high-liberal view, our dignity as human beings is
itself implicated in our civic identity, and hence our lives as citizens count for a great
deal in establishing or expressing our moral status.
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(d) Kant and Aquinas – Is the Law the Soul of the Community?
I have suggested that in an ideal community (the realm of ends) we should
regard the members as the matter and the law as the form. To finish, I would
like to distinguish between the way in which the law is the form of a realm of
ends for Kant and the way in which the intellectual soul is the form of the
human body for Aquinas. At first sight, this might seem to be an odd topic
to address, but I think this may help us to understand something important
about Kant’s ethics and his conception of a realm of ends.
Aquinas argues that ‘the human being is a composite of soul and body,
not the soul alone’ (ST 1, 75, 4, p. 62), and that the human soul is an
intellectual soul which is ‘a pure form’ (1, 75, 5, p. 65). The soul is the source
of intellectual activity and, for Aquinas the intellect is not united to the body
as ‘the efficient cause that moves the body’ (1, 761, p. 65) instead,
the source of activity is the form of the thing to which we attribute the
activity . . . [T]he soul is the primary source whereby we nourish ourselves and
sensibly perceive and move ourselves from place to place, as well as the
primary source whereby we understand.
(1, 76, 1, p. 65)
For the law(s) to be the form of the kingdom of ends in a way similar to
that in which, for Aquinas, the intellectual soul is the form of the human
body the law would have to be the source of all the vital activities of the
community. On a fairly common misreading of Kant, it would seem that
he would accept something like such a claim. According to such
misreadings, to be moral involves not acting from inclination, with the
suggestion that it is the law itself which is ultimately the source of all
moral action. If this were the case, then Kant’s account of the relationship
between the law and the individual members of a realm of ends would
seem to be remarkably similar to Aquinas’ account of the relation between
the human soul and body.
As I understand Kant, however, in a realm of ends, it is not the law that
acts but the individual members of the community that act, with the law
being understood as placing limits on the inclinations of each individual
member, but not replacing it. In scholastic terms, this would be to say the
source of activity in a kingdom of ends is the matter (the members) not the
form. This question really comes down to the question of what, or who, in
a realm of ends, really acts? The law or the individual members of the
community? According to the traditional reading, the law is basically
acting through the individual members of the community, but according to
the present reading, the individual rational human members of the
community are causally efficacious intentional agents by means of their
desires, which incorporate the moral law intrinsically when and only when
they are fully autonomous. For Kant the law does not replace inclinations,
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but merely orders or structures them, and it is this rational ordering and
structuring of our inclinations which completes both ourselves and the
law.
48
Philosophy Department
Bo
gazic¸i University
48
In addition to audiences at various workshops and conferences where I have presented
material from parts of this paper, I would like to thank Paul Guyer, Shane Duarte, Michael
Rohlf, Bill Wringe, Sandrine Berges, Ilhan Inan, Sun Demirli, Berna Kilinc¸,Zu
¨beyde Karada
g,
Alix Cohen, and Robert Hanna for comments on earlier versions of this paper.
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