## 1. Life and Writings



Although Robert Desgabets (1610-1678) is perhaps the most
original of the Cartesian thinkers, even lauded by his most famous
student, Pierre-Sylvain Regis, as "one of the greatest
metaphysicians of our century" (Regis, 1704, 328), only one book
and two small works were published anonymously during his
 lifetime.[2]
 His correspondence indicates that he was interested in mechanics
before 1644, prior to his acquaintance with the writings of Descartes.
For a metaphysical thinker like Desgabets, it was Descartes, not
Galileo or Bacon, who offered a new and complete philosophic system.
In Desgabets's estimation, the only legitimate rival system to
Descartes's was the one developed by Pierre Gassendi, but in the
final analysis, the "new scientific discoveries" weighed
decisively in Descartes's favor.



In 1658 Desgabets participated in the Cartesian conferences held at M.
de Montmort's where he reportedly participated in discussions
with Rohault, Clerselier, and Cordemoy. Desgabets delivered a lecture
which outlined his invention of an apparatus and procedure for blood
transfusion, but he seems to have abandoned its study shortly
thereafter. In 1667, after a controversy erupted between the English
and the French over who first invented the procedure, a French
physician by the name of Jean Denis was spurred to publish the written
version of Desgabets's lecture. This appeared in 1668, four
years after the physicians Clark and Henshaw of England had attempted
the operation on animals without success (Desgabets, 1668). Prior to
this research, in 1656, Christopher Wren successfully injected
medications directly into the veins of animals, after which in 1665,
another Englishman and physician, Richard Lower, a teacher and friend
of John Locke, successfully injected blood into animals using this
same method. Genevieve Rodis-Lewis has sorted out many of the details
of this history and shows that the two procedures created by Lower and
Desgabets are so different as to confirm the independence of their
inventions (Rodis-Lewis, 1974). But whether and when Desgabets
experimented with his procedure has not been firmly established. What
is evident, however, is that Desgabets, like Wren, was inspired by
Harvey's discovery of the circulation of blood. Once Harvey had
shown how the circulation of blood is best understood as a mechanistic
process operating according to lawful movements, he opened the way for
blood transfusion to be understood along similar lines, as a species
of the communication of movement. Where evidence of Desgabets's
actual experimentation with blood transfusion is lacking, his
descriptions of it show that he was aware of the possibility of shock
if the quantities transferred were too great for the subject
(Rodis-Lewis, 1974).



Throughout his lifetime Desgabets engaged in many theological and
philosophical controversies with distinguished seventeenth-century
thinkers such as Mabillon, Rapin, Foucher, Malebranche, Cordemoy,
Arnauld and Poisson. One of his more famous interlocutors was the
Cartesian Gerauld de Cordemoy (1626-1684). Despite his
admiration for Cordemoy, Desgabets was dismayed by the atomism in the
*Discernement du corps et de l'ame* (1666), a copy
of which had been sent to him by Clerselier. Desgabets subsequently
wrote to Clerselier, opposing Cordemoy's arguments for the
existence of the void and against the infinite divisibility of
extension. In an unpublished letter to Clerselier, Desgabets comments
that the marriage of Cartesian and anti-Cartesian elements in this
work formed an irreconcilable schism in the Cartesian philosophy.
(Prost, 1907, 158) Although Desgabets himself was not one to adopt
Cartesianism in its entirety, in his view his criticisms perfected and
maintained the integrity of the Cartesian principles, while
Cordemoy's adoption of atoms and the void was a direct affront
to the Cartesian
 metaphysics.[3]



Another, much more scandalous exchange took place between Desgabets
and Thomas Le Geant between 1671-1672 over
Desgabets's thoughts on the Eucharist. Desgabets published his
views anonymously in *Considerations sur l'etat
present de la controverse touchant le T. S. Sacrement de
l'autel* (1671). Lemaire credited this work with having been
the primary cause of the persecution of Cartesianism in France, since
it brought to light the incompatibility of the Cartesian philosophy
with the official Church doctrine on the mystery of the Eucharist
(Lemaire, 1901, 124). Desgabets had entered the on-going debate
regarding Christ's real presence in the host in 1654 at
Clerselier's request. Desgabets set out to defend the Cartesian
doctrine of material substance against the Peripatetic doctrine of
substantial forms in his explication of real presence and
transubstantiation. Clerselier and Rohault had defended
Descartes's ideas on the subject along similar lines, but no one
had been willing, either privately or publicly, to argue as Desgabets
eventually did, that the body of Christ is extended in the host. In
addition, Desgabets's persistence and perhaps even imprudence,
pushed the issue into the open. For, it was shortly after the
publication of the anonymous *Considerations* that
Desgabets sent additional writings on the topic to Abbey Le Roi, who
communicated them to Nicole and Arnauld. The latter found
Desgabets's views dangerous and completely against tradition. It
was through his acquaintance with Nicole and Arnauld, that the
non-Cartesian Le Geant learned of the document and the identity
of its author. Le Geant alerted the Procurer General of the
Congregation of Benedictines, who ordered Desgabets to report to his
superiors concerning the matter. This led to an interrogation and the
subsequent issuance of an order on the 15th of December 1672, which
demanded that Desgabets renounce his views on the Eucharist
(Armogathe, 1977, 104-105; Lemaire, 1901, 51; 127-128).
Desgabets obeyed and retreated to a monastery at Breuil. Fortunately
this did not end his philosophical productivity. The controversy
attracted the attention of Cardinal de Retz, who was known for his
radical spirit of reform among conservative ecclesiastics in France.
Cardinal de Retz, who was a partisan of the new Cartesian philosophy,
provided protection for Desgabets and invited him to the Cartesian
conferences held at Chateau de Commercy. It was here that Desgabets
criticized and corrected what he saw as the errors of Descartes, and
completed his "indefectibility thesis," which he had
started in 1653-1654.



Desgabets's last published work, *Critique de la critique de
la Recherche de la verite* (1675), was intended as a
defense of Malebranche against the skeptic Simon Foucher. The
controversy began with the publication of Malebranche's
*Recherche de la Verite* (1674), followed by
Foucher's critique, *Critique de La Recherche de la
Verite* (1675), and Desgabets's rejoinder,
*Critique de la Critique de La Recherche de la Verite*
(1675)*.* Foucher presses Malebranche on a number of issues he
sees as errors of dogmatism, centering on how ideas can be said to
represent external objects to us. Foucher argues that ideas fail to
represent if ideas share no likeness or similitude to their objects.
Desgabets replies that ideas have an intentional or representational
resemblance not a strict resemblance in the sense in which a painting
pictures its subject. Desgabets's response on behalf of
Malebranche did not settle the controversy, nor was it appreciated by
Malebranche himself. Malebranche wrote that although he was pleased
with the person, he was not pleased with the contents of his book; he
further lamented that Desgabets ought to have better understood his
ideas before taking on a defense. Desgabets himself was never to see
Malebranche's scolding assessment which was published in the
"Advertissement" of the third edition of the *Search
After Truth* (Malebranche, 1958-84, v2, 500-503).
Desgabets died at Breuil on March 13, 1678, just fourteen days before
it appeared.



Desgabets's most important philosophical text,
*Supplement a la philosophie de M. Descartes*
(1675), was intended as a supplement to Descartes's
*Meditationes de prima philosophia* (1641)*.* In this
work, Desgabets examines many of Descartes's important doctrines
and arguments. Desgabets defends the Cartesian doctrines of sensible
qualities, matter as extended substance and mind as thinking
substance, mind-body dualism, mind-body union and interaction in man,
while criticizing Descartes's argument for the *cogito*
as the first principle of knowledge, as well as Descartes's
arguments for pure intellection, innate ideas, and ideas having
objective reality (pure possibility). What is particularly interesting
is the central importance that Desgabets gives to the role of
sensation in knowledge, and his development of Descartes's
treatment of truth as both eternal and immutable but in some sense
(one much contested in the literature) contingent. Desgabets more than
once remarks in this work that "M. Descartes is not always a
good Cartesian," which typifies his conviction that Cartesianism
is more than the sum of the particulars set down by Descartes
himself.



Viewing Desgabets's work as a whole, there is no doubt that what
he viewed as a revision or perfection of the Cartesian philosophy
others have viewed as a fundamental departure. In his favor, he never
strayed from the Cartesian metaphysics, i.e., its substance dualism of
mind and matter, substance-mode ontology, mind-body union and
interaction, and the view that extension is the essence of matter and
thought the essence of mind; and he remained loyal to the Cartesian
physics against the atomists. However, heretically to some, he
strongly rejected several key rationalist doctrines which often
dominate in Descartes and argued that Descartes's own principles
favor a sensory foundation for knowledge.


## 2. Metaphysics



Desgabets has been variously described as an "orthodox
Cartesian" for the fidelity with which he defended Descartes
against his critics (Watson, 1966; 1987), and a "radical
Cartesian" for the originality of his ideas in the development
of the Cartesian philosophy (Schmaltz, 2002; Adriaenssen, 2015). On
the side of orthodoxy, we can see Desgabets's adoption of the
new Cartesian philosophy in his adherence to the core Cartesian
metaphysics of dualism, mechanism, and union, and his various
critiques of Scholastic doctrines. On the side of radicalism,
Desgabets took up arguments and ideas that would be difficult if not
impossible to reconcile with Descartes's published philosophy.
There is Desgabets's argument that the body is essential for all
operations of the human mind making innate ideas impossible, his
defense of the intentionality principle, and his controversial
doctrine of indefectibility especially with respect to matter, and his
unorthodox defense of the "Creation Doctrine." Notably, as
Malfara and Lennon have argued, there is Desgabets's development
of the metaphysics of matter in the Eucharist controversy, which
serves as a fascinating philosophical and theological litmus test for
Desgabets's Radical Cartesianism (Malfara & Lennon,
2023)



Desgabets subscribed completely to the Cartesian doctrine of matter as
a substance extended in length, width, and breadth. It was posited
against the prevailing Peripatetic view that posits prime matter and
substantial forms in order to explain the permanence underlying the
continuous change matter undergoes. On Descartes's view, the
essence of matter is its extension in three dimensions, and all of its
changing attributes, properties and modes, such as movement, rest,
figure, situation and composition of parts, are completely dependent
upon and follow from this unified extension (OPD 2, 27). Matter, or
corporeal substance, is clearly known when it is viewed as the
geometrical object of mathematicians, as a magnitude extended in
length, width and breadth. Likewise, corporeal bodies are best viewed
as the movements, rest, figures, arrangements and sizes of which
corporeal substance is capable, and which, in its various
configurations and assemblages, "... now pass for the form
of all particular bodies of which the world is composed" (OPD 1,
3). And, in all of this, "... there is nothing which is not
governed by the laws of mechanics" (OPD 2, 4).



Furthermore, Desgabets viewed bodies as portions or divisions of
matter, which in the case of animals are highly delicate and organized
machines composed of an infinite number of parts capable of an
infinite diversity of movements. He held this view against that of the
Peripatetics who believed that there must be an internal principle of
thought in beasts because of the intricacy and apparent human-like
intelligence of their movements. According to Desgabets, the kind of
thinking that attributes such an internal principle to beasts is the
same kind of thinking that results in the attribution of intelligence
to clocks, "However, the same affront to reason and philosophy
is committed by the Americans and the Barbarians of the Orient who not
being able to understand the mechanical reasons for the movement of
clocks, or the true causes of natural effects, attribute souls and
intelligence to machines, and likewise to fire, lakes etc., and in
doing so expose themselves to the mockery of Europeans" (OPD 4,
132-133). In other words, no appeal to internal principles, or
final causes is required to explain the movements of beasts, any more
than it is needed to explain the movements of clocks. The complexity
of movements, whether involved in the operations of clocks or those of
animate bodies, is explicable in purely mechanistic terms.



Likewise, all motions communicated within or between material bodies
are effected by physical contact and proceed according to the laws of
local motion. Desgabets was careful to emphasize that the ultimate
source of movement is not matter but God, who imparted motion to the
universe in its creation. For Desgabets, it is this fact that grounds
the laws of nature: "It is the constant and uniform manner of
the action of God which founds these laws, by means of which He forms
and maintains this beautiful harmony in the world which is one of the
greatest objects of our sciences" (OPD 1, 13). As Desgabets saw
it, the operation of these laws of nature and the rules of the
communication of movement were the true and unique foundations of the
new physics.



Desgabets also subscribed to the Cartesian conception of mind as an
immaterial substance whose essence is thought. The distinction between
mind and matter is thus a real and substantial one, impossible not to
perceive: "Never has an infant asked for lies or truths for
breakfast, nor has he imagined that the stones encountered along his
path were the gross thoughts of some countryman" (OPD 5, 197).
Minds, or immaterial substances, are of three kinds: uncreated, which
is God; mind detached from body, which is an angel; and mind united to
organized body, which is a reasonable soul. The second of these,
angels, are the only pure minds in the created universe and they have
no corporeal extension, no local presence or correspondence to
time--they are simple and indivisible minds. Such minds or
spirits cannot be perfected by any substantial union since their
specific spiritual being does not require anything corporeal to carry
out its functions. However, they are capable of participating in the
movements of the visible world, though in doing so, they must undergo
a kind of degradation and punishment in order to receive pain. The
third of these spiritual beings is man, who consists of a cross
between purely intellectual and purely corporeal things. In this
Desgabets appears to have strayed slightly from the official Cartesian
doctrine of dual substances, since he claimed that outside of God
there are three sorts of simple created substances, matter or body,
angel, and one which is composed of body and soul, which is man.
However, this tripartite division of substances is supported by a more
fundamental bipartite division of material and spiritual substances,
so that strictly speaking, individual bodies and individual persons
are best understood as *modal beings* not substances. This is
not unlike Descartes's account of man as a "composite
entity" possessing two principal attributes, namely extension
and thought, a being which itself is not a simple substance.
Nonetheless, in Desgabets as in Descartes, how to interpret the human
soul as a substance (Miller, 2008), or as a modal being (Lennon,
1994), is a matter of continued debate.



It was an important point for Desgabets that man, unlike angels, is a
being composed of body *and* soul, who continually experiences
the union of the two substances by the endless impressions he finds in
himself. The relation of mind and body in man is an essential one
which must not be regarded as a penal state of the soul, but as the
*accomplishment* of its natural perfection. Human thought has
duration, succession, a beginning and an end--qualities that
depend on the movements of the corporeal organs and which follow the
rules of local movement. Although Descartes and Malebranche after him
claimed that the human mind is capable of detachment from the body,
Desgabets rejected this, since the human mind is not like an
angel's but requires continual commerce with the body and its
senses for all its operations.



One further issue concerning Descartes's general account of the
nature of the mind-body union, which Desgabets raised in order to
dispel, concerns the common complaint that the Cartesian view fails to
account for the interaction of material and immaterial substances.
Desgabets did not regard this as a true problem because he thought
that the question demanded the impossible--an explanation of how
the organized body and reasonable soul, which are in fact made for
each other, *can* exercise a mutual commerce. He likened this
to asking an artisan to explain how the convex surface of a peg
*can possibly* fill that of a concave hole. It is akin to
asking why extension is the essence of body, or why thought is the
essence of mind. It's just the way God made the world.



What could be explained, according to Desgabets, is the way in which
the mind and body are in fact united and dependent upon one another.
He found an analogue in the nature of the body-body relation: two
bodies are united when their superficies touch and their movements
take on a mutual dependence. Similarly, two minds are united when
their thoughts and wills agree and depend on one another. The union of
mind and body is not by touch, nor by agreement of thoughts, but by
the dependence that exists between certain thoughts and certain
movements such that one in fact *follows from* the other. The
union of the mind and body in man is so strict that it founds a
species of communication for their commerce, in virtue of which our
thoughts are said to have duration, succession, etc., without
themselves being corporeal. The union and its interaction cannot be
further reduced in explanation. In short, the essence of man, who is
composed of mind and body, *is* the union of mind and body, and
the only legitimate questions which concern this union relate to how,
*given* the union, the mind determines the body and the body
determines the mind, which is an empirical question, known through
experience not reason.



Desgabets's thesis concerning the indefectibility of created
substances, which underlies his metaphysics, is perhaps his most
original if not radical philosophical contribution (Schmaltz, 2002;
Easton, 2005; Gatto, 2017). Gatto argues that this thesis is the key
to understanding Desgabets's peculiar development of
Descartes's philosophy (Gatto, 2017). In a letter from Desgabets
to Malebranche, we learn that he had begun the *Treatise on the
Indefectibility of Substances*, as early as 1649 (Letter from
Desgabets, Sept. 1674, Malebranche, 1958-84, vol. II: 85). It
was Desgabets's view that substances, in their essence and
existence, are eternal, indivisible, immutable, and indestructible,
which is to say, indefectible. While the modes of substance can
undergo change, the essence of substance and its existence cannot.
According to Desgabets, the indestructibility, eternality, and
indivisibility of substances follow from the fact that God created
substances by a free and indifferent will. Once the world was created,
it could not be uncreated. Thus, the key to understanding
Desgabets's indefectibility thesis lies not only in his analysis
of the Cartesian doctrine of substance, but in his interpretation of
Descartes's notoriously opaque doctrine of the free creation of
the eternal truths, discussed in a later section, under
"Truth."



As we have seen, Desgabets's adoption of the new Cartesian
philosophy came with radical revisions that Descartes himself likely
would not have sanctioned. As Desgabets himself puts it in Preface to
the *Supplement*, Descartes made the true philosophy possible:




> 
> 
> I will again affirm that we need only look at the works of Descartes
> to speak thoroughly of these four great subjects I have just proposed.
> He raised them all with the purpose of treating them and had views so
> extensive concerning them that we cannot fail to profit notably from
> his work, if we take the trouble to examine his ideas. Nonetheless, I
> must show in what follows that after delivering us from infinite
> error, he himself was caught in imperceptible prejudices concerning
> fundamental things, which deprived the world of the greatest fruits of
> his work. I will take the occasion of his own inventions to mark the
> places where he failed and to extend them as far as he should have. I
> will uncover the contrarieties that are found among the things he
> advanced and how sometimes he himself ceased to be a good Cartesian,
> by abandoning his finest discoveries to embrace popular opinions. I
> will show that it is almost by his own doctrine that the errors are
> corrected and that it is he who gives the remedy for the ill he
> produced. I will establish his reputation upon eternal foundations by
> giving his philosophy its expected reputation. For, it has to be known
> that his philosophy, once purged of certain errors and having received
> the vast scope possible to it, must pass for the masterpiece of the
> human spirit, and for what is the greatest of its kind in the world
> (OPD 5, 152).
> 
> 
> 


## 3. Epistemology



There is a long tradition of interpreting Desgabets as an empiricist
from Victor Cousin (1852), and Francisque Bouillier (1868), to
Genevieve Rodis-Lewis (1981, 1993), Patricia Easton and Thomas Lennon
(1992), Tad Schmaltz (2002a; 2002b) and Sean Allen-Hermenson (2008).
Monte Cook (2008) has raised an important challenge to the empiricist
reading, questioning whether the senses provide any real content to
our ideas. A discussion of some of the interpretive complexities
around sensible qualities, the nature of ideas, the intentionality
principle, and the method of truth follows below. Nonetheless, there
is consensus that Desgabets rejected hyperbolic doubt, pure
intellection and innate ideas, and insisted on the necessary role of
the senses in the formation of all ideas. Moreover, it is agreed that
these positions lean away from Descartes in varying degrees and
constitute a major if not radical revision of the Cartesian
philosophy.



In Desgabets's estimation, Descartes's truly great
discovery was his identification of the true nature of sensible
qualities (OPD 5, 164). The importance of this 'discovery'
in Desgabets's development of the Cartesian philosophy is
paramount, since he believed that because of it, the way had been
opened at last to lay the foundations of a true philosophy. Desgabets
drew out six important consequences (OPD 5, 165ff.), which he admits
shows that "Descartes is mistaken in what is the most
fundamental in his method" (OPD 5, 164). The six consequences
are: (1) sensible qualities "... are nothing else in
objects but the local dispositions of the small parts from which
result the sensations that we call heat, sound, light, etc."
(OPD 2, 17); (2) sensible qualities are sentiments in the human soul
that have no resemblance to modes of matter, such as shape, size, and
motion; (3) external objects have the power to excite innumerable
perceptions in us that we call sensations and ideas; (4) simple
conceptions arise in us from objects outside us and are known truly,
as they really exist; (5) knowing the true nature of sensible
qualities as perceptions of the mind caused by bodies makes possible
the true physics; and, (6) by distinguishing the true nature of the
body from the sensible qualities it causes in us, we can unite physics
with the infallible sciences, for the solid of the geometer is the
same as the object of the physicist (extended matter). Each of these
consequences will be examined in more detail to investigate what was
at the heart of Desgabets's adoption and revision of the
Cartesian philosophy.



(1, 2, 3) Sensible qualities are states or modes of the human mind
having only a causal relation to the specific local movements of our
sensory organs, which in turn, are the effects of the local movements
produced by the corporeal qualities of matter. According to both
Descartes and Desgabets, sensible qualities are nothing but
"various dispositions" in objects to cause ideas in us.
Since Descartes clearly held that sensible qualities are not the
*forms of material things* but rather *modes of the
mind*, the only sense in which sensible qualities could be
"in" the various dispositions of objects is in the causal
sense, that is, as their effects. While the status and nature of these
dispositions in Descartes's account has been a subject of much
debate, he undeniably distinguishes between on the one hand, light,
color, smell, taste, sound and touch (the so-called secondary
qualities), and on the other hand, size, shape, and motion (the
so-called primary qualities). Sensible qualities belong to the mind as
modes of perception, and primary qualities belong to body as modes of
matter. Desgabets follows suit by adopting the Cartesian distinction
between minds and bodies, thereby attributing size, shape, and local
motions to body as modes of matter and sensible qualities such as
heat, color, smells, sounds, pains and pleasures, and tangible
qualities as modes of thinking things. Thus, sensible qualities
*qua* modes of the mind have no resemblance or similarity to
the modes belonging to matter: "the sun is not luminous, the
snow is not white, the fire has no heat in the sense that we imagined
previously." (OPD 5, 165) However, Desgabets maintains that
sensible qualities *qua* modes of mind do represent the soul
*and* its relation to corporeal things, just as our ideas of
body and its modes when clearly perceived as shape, size, and local
motion, truly represent their object. How this is so brings us to the
fourth consequence, that our simple conceptions arise in us from
objects outside us and are known as they actually exist.



(4) Eclipsing the *cogito* as the first principle of knowledge
in Desgabets's system is what has come to be known as the
"intentionality principle" (Schmaltz, 2002; Hill, 2011;
Adriaenssen, 2015). According to Desgabets by reflecting on the true
nature of sensible qualities we are able to grasp the most general
principle underlying all truths: *that simple conception or the
first operation of the mind is always true and conforms to its
object*. As Desgabets describes this foundational principle:
"... that every idea has a real object; that nothing cannot be
thought; that simple conception always conforms to its object; that to
think and to think of something are inseparable things, and as the
natural order would have it, we begin to philosophize by the
exposition and development of this great principle ..." (OPD5.
178). If such a principle could be established, as Desgabets claims
that it can, it would mean that simple conception conforms to its
object, it preserves the truth, and hence provides the foundation for
human knowledge. Most of Desgabets's discussion of the
intentionality principle treats it as self-evidently true. If we
reflect on the nature of human thought itself--as by its nature
presupposing an object--then we see the absurdity of there being
a thought with no object. If we reflect on the existence of human
knowledge itself then we see that it presupposes knowable
things--for what is knowledge unless there are prior knowable
things? The intuition Desgabets seems to be working with is that
*given* there is human thought and knowledge, *there must
be* objects of thought and objects known to make it possible. 



Although Desgabets gives a new meaning to the doctrine of simple
conception, he and Descartes agree that simple conception is always
true and conforms to its object, while error is a product of
precipitous judgment. This is a theme found in Descartes that depends
on the Cartesian distinction between the scope of the two basic
operations of the mind--that of the intellect and that of the
will. The functions of assenting and dissenting are performed by the
will, while those of perception and conception are performed by the
senses and intellect. Desgabets challenges Descartes's
"pretension" that he could detach himself from all
commerce with the senses, which sets the rationalist tone of the
*Meditations*. Of course, Descartes saw this detachment as
desirable because he thought it was in virtue of it that he could
avoid error and defend the certainty of human knowledge. Descartes
also argues that the soul is known more clearly than the body because
we, as thinking things, are intimately tied to the immaterial,
thinking substance, which is our soul. The body, on the other hand, is
part of material not immaterial substance, and so is not known
immediately. It is because of this that Descartes took the
*cogito* to be the foundation of certainty in human knowledge,
and our knowledge of body to be less clear and less immediate.
However, according to Desgabets, this is where Descartes goes terribly
astray. Had Descartes reflected more deeply on the nature of the
mind-body union, he would have seen that our ideas of body and mind
are equally clear, and equally evident. For, the soul of man is not an
immaterial substance, but is a result of the union of mind and body,
and all our ideas, even of the soul, equally depend upon the operation
of the senses. From here, it can be seen that there is a principle
more fundamental than the *cogito*, namely the principle of
intentionality, *that to think is to think of something.*
Clarity and distinctness, according to Desgabets, tells us when we
have grasped something truthfully, but the intentionality of thought
grounds the truth of clarity and distinctness.



But how, according to Desgabets, are we to distinguish a simple
conception from a precipitous judgment? In his
*Supplement* (OPD 6, 222) he offers the example of the
heat of fire to illustrate the distinction: when someone approaches
fire and has the sensation of heat he may be persuaded that the heat
he feels is in the fire just as he perceives it, since this sensation
is known to him clearly. But, he has erred because of a tacit
judgment. The judgment that the heat is in the fire entails that the
heat as we perceive it resembles what is in the fire, which is false.
For, as Descartes discovered, the sensation of heat is a mode of the
mind, not a mode of the fire (body). The fire we feel "... is
the object of simple conception only when we do not conceive this heat
as in the fire, rather as something that makes us have this feeling
when we approach the fire. But if one says the heat of the fire
resembles the sentiment that is our heat, a judgment is added to
simple perception and falls in error because the judgment extends
beyond the perception" (OPD 6, 222). Likewise, when we judge
that a stick is straight or bent when half-submerged in water we judge
precipitously--what is known is that it is equally real and
conceivable that a stick (as a material body) is straight or curbed
(is shaped) (Desgabets, 1675, 67-68). Thus, simple conception
grasps its object clearly and represents the thing perceived as it
really is. When we perceive the heat of the fire *simpliciter*,
we perceive the sensation of heat as a sensation of the mind; when we
perceive the fire *simpliciter*, we perceive it as a corporeal
body having extension and local configurations and motions. Simple
conceptions are the mind's grasp of things as they are in
themselves, which is to say, in relation to their essence and modes as
extended substances, or as thinking minds: "We therefore have
only to think of extended substance which is matter, of its movements,
of its figures, of the situations of its parts, of angels, of souls,
of men and their operations, to be very sure that all this exists. For
whether thought represents to us substance or accident, body or
spirit, it is equally necessary that all of these exist outside of
thought, unless one thinks without thinking of anything, and the first
operation of the mind ceases to conform to its object"
(Desgabets, 1675, 124). A related error made by Descartes, according
to Desgabets, is to allow chimeras and other such beings of reason
among the number of objects of simple conception. Such a mistake
obscured Descartes from discovering the true foundation of human
certainty, the basic truth that the first operation of the mind has
only *real* things for its object. By including chimerical
beings among the objects of simple conception, Descartes opened the
door to the possibility of thoughts without true objects. But,
judgment or the extension of the will beyond the domain of what is
conceived is the true source of chimerical beings of reason and hence
of all error (OPD 4, 103).



(5 & 6) Desgabets drew two more final consequences from
Descartes's discovery of the true nature of sensible qualities.
In order to make physics a true science, Desgabets must accomplish two
things: first, show that the senses are necessary for the knowledge of
physical objects and; secondly, show that physics is founded in
infallible sciences (mathematics and geometry). The fifth consequence
thus aims to establish that perceptions of the mind are caused by
bodies and makes possible the true physics. In Part 1, chapter three
of the *Supplement*, Desgabets explicitly examines
Descartes's rejection of the empiricist motto, that all
knowledge comes from the senses. While Desgabets rejects the
Scholastic rendering of the motto, he is equally critical of
Descartes's precipitous rejection of it. According to Desgabets,
the proper sense of the empiricist motto is that all thoughts
*originate* by the senses [*a sensu*] rather than in the
senses [*in sensu*], and what reaches the intellect is not what
is found in the senses. As Lennon nicely puts it, "For him
things are directly perceived and an idea is the means by which, and
not in which, a thing is perceived" (Lennon, 1998, 353). The
soul must always be in commerce with the senses by the nature of the
mind-body union, and although our thoughts depend on the corporeal
traces in the brain for their source or origin, it does not follow
that our ideas must be corporeal, or even similar to corporeal things.
The very fact that all of our thoughts have a beginning, duration,
cessation, and succession proves that they depend on motion, and
motion is only communicated through the senses. This is why he
modifies the empiricist motto from: *nihil est in intellectu quin
prius fuerit in sensu*, to *a sensu*.



While this formulation of the empiricist motto goes against the notion
of pure intellection, it leaves open the question of whether the
senses play more than an occasional role in the occurrence of all
thoughts, including about body. According to Desgabets, it is
undeniable that man is a being who reasons, draws consequences, does
not see things indivisibly, who has thoughts in succession which
begin, continue, and finish, and who often experiences doubt and
conjecture. Such doubting, discursive reasoning and succession of
thought prove that all thought is tied to the body since duration and
successive extension are nothing but the local movements of the body
(OPD 7, 299). A pure thought, the kind that Descartes (and Malebranche
after him) envisioned for metaphysical reasoning, would have no
beginning, duration, end, or succession. In short, such a thought
would be indivisible, and hence unthinkable by the human mind. Both
Descartes and Malebranche rejected the empiricist thesis because they
erroneously thought that it would commit them to the materialist
thesis that thoughts and the soul are material. This led them to adopt
the intellectualist thesis regarding the mind's perception of
metaphysical essences. However, Desgabets saw a third option, one
which is founded on the mind-body union and the sensory basis of all
knowledge, and one which founds the full and proper sense of the
empiricist motto, that all ideas originate by the senses. Since
movement is a mode belonging to body, many tended to conclude that if
minds depend on movement, then minds must have something corporeal in
them. How could it be that our thoughts, which have something
corporeal in them, namely, movement, are not themselves corporeal? And
yet, this is exactly what Desgabets argued. He believed that thoughts
have something corporeal in their being without themselves being
corporeal--in the same way that every object in our thought has a
beginning, continuation, and end without these objects having duration
in themselves. While things really have duration, it is only
*extrinsically* and by thought, "the same way a pole is
divided into ten feet when one imagines the ten feet" (OPD 7:
299). 



At first glance, Desgabets's analogy between attributing a
corporeal nature to thoughts and attributing a duration or division to
things serves more to confuse than clarify. But if we draw on his
account of the true nature of individual bodies, we can make some
sense of it. Individual bodies are real in that they result from
actual divisions of matter, assemblages of local dispositions of parts
of matter. Bodies then act upon our sensory organs which in turn are
received as ideas in the mind. But the *individuation* of
perception into *sensible* ideas of bodies is essentially an
operation performed by the mind, even though it has its foundation in
the local dispositions of matter itself. For example, our perception
of a ten-foot pole is the effect of a specific assemblage of local
dispositions of matter acting upon our sensory organs at a certain
time *and* the mind's division of that sensible body into
ten feet. The local disposition itself is not intrinsically a pole, or
ten feet long, but it is so extrinsically, that is, by thought.
Similarly, thoughts themselves are not intrinsically extended or
subject to movement, but they are so extrinsically, that is, as an
effect of the operations of the sensory organs of the body. In other
words, just as the local movements of matter individuate thought
extrinsically giving the mind individual thoughts, the thought of
immaterial substance individuates matter extrinsically thereby giving
it perceptions of individual bodies. The mind-body union, and the
essential intentionality which results from it, create the mutual
dependence of the operations of mind and matter without requiring that
mind be material or matter be immaterial.



This does not mean that the senses cannot access the true nature of
things. In fact, for Desgabets, since all knowledge comes from the
senses, the function of knowing the essences of things is a necessary
role served by the senses. Recall that the true nature of particular
objects consists in the local dispositions of parts of matter which
produce the course of the movements we experience. Think of these
sensible objects as akin to Humean bundles of perceptions except that
for Desgabets there is a causal relation to the object of our idea
that ensures a conformity of the perceived object and the object.
These movements are the first and sole contact we have with the
material world, and so the senses present, in some form, not only the
existence of a given object, but also the value of that object in
relation to our survival. We only reach knowledge of the true nature
of material objects by considering their being in relation to their
substance. In order to achieve this, we must abstract from all
relations of time, and only then see it as it is in itself. What the
senses provide us is knowledge of matter in its various divisions,
shapes, sizes, etc., that is, as matter in its parts as it exists at a
certain time and place. Thus, what Desgabets seemed to have assumed
was that the reason we so often err with regard to the true nature of
these bodies and their movements is that we judge precipitously, or
too quickly, before the mind has had a chance to conceive of material
substance as it is in itself, independent of any temporal or spatial
ties. Thus, it seems that Desgabets holds that the senses provide us
with the materials necessary not just for the occasioning of thoughts
of bodies but also for the knowledge of their essence. 



The sixth consequence bears directly on our ability to see the right
path to a true and certain physics. The true physics is one that
recognizes that "everything that happens in matter by the
different movements and modes of its parts, belongs to mathematics and
mechanics, which have all of this for their object" (OPD 5,
166). The object of the true physics is not the substantial forms of
the Scholastics, but rather, matter whose essence is extension, and
its modes which are nothing else but various divisions and movements
of its parts. As Desgabets puts this, the natural object of the
physicists is the same as the solid of the mathematician. The solid of
mathematicians, according to Desgabets, consists in a magnitude that
has three dimensions, i.e., length, width, and breadth while the
natural body of the physicist consists in a substance extended in
three dimensions. This is the crowning statement of Desgabets's
metaphysical view that the physical world is *really* a single
object or substance whose parts, under various divisions, shapes and
arrangements, form all the *appearances* in the "grand
theater of nature" (OPD 5, 166). Once physics is united with the
infallible sciences of mathematics and mechanics, the path to the true
science of physics is secure.



Having surveyed the six consequences of the true nature of sensible
qualities we can see the heart of Desgabets's revision of
Cartesianism: that in order to use reason properly we must recognize
that all our ideas or simple conceptions have a real object outside of
it, which is in itself what is represented by thought, and which
actually contains the degree of being that one sees there. The work of
the search after truth is to avoid precipitous judgment and keep to
the simple conception of things. If body is extended in three
dimensions capable of modes of size, shape and motion, and individual
bodies are modal beings in the sense claimed by Desgabets, then there
is no cleavage between object and object known because they are one
and the same thing. Corporeal things cause sensible ideas in us that
represent modes of the mind and cause ideas of bodies, shapes, sizes,
and motions that represent matter. What is represented to our thought
through simple conception is the real object of knowledge, namely,
material and spiritual substance. What we sense directly are these
substances as they exist in time, or in other words, as they exist at
a given time *by thought* in virtue of the particular local
dispositions of matter.


## 4. Truth



According to Desgabets, Descartes's fine doctrine concerning the
creation of the eternal truths, is the foundation of the true
(Cartesian) philosophy. He claimed that had Descartes attended
consistently to this doctrine, he would have avoided all error. Due to
its importance and opaqueness in Desgabets's writings, the
"Creation Doctrine" has generated a great deal of
examination and debate, most recently stimulated by Beaude's and
Rodis-Lewis's publication of Desgabets's philosophical
writings (Desgabets, 1981). Rodis Lewis (1981) and Lennon (1998) set
the stage for the dialectic of the debates in the period. Schmaltz
(2002), Cook (2005), Faye (2005), and Easton (2009) variously argue
for the importance of the doctrine in Desgabets's development of
the Cartesian philosophy, and its philosophical significance. Gatto
(2017) presents a nice synthesis of the literature and sorts out the
complicated reception and role of Descartes's doctrine,
particularly for Desgabets. Despite the controversies surrounding the
interpretation and significance of this doctrine, there are some
points of agreement. As Desgabets understood it, the Creation Doctrine
requires that God be equally the author of all created things, in
their being and their essence. It requires that there be no essence
without existence, which is to say, that there can be no purely
possible beings either in the human mind as Descartes allowed, or in
God's mind, as Malebranche argued. The notion that such truths
are in some way prior to God's creation of the world, existing
as purely possible essences separate from actual existence, involves a
separation of essence from existence, and supposes that essence is
something actually separable and conceivable without existence.



Truth, which exists only by the relation of conformity of thought to
its object, is contingent in that it depends on God's will in
his free creation of the universe. Truth is eternal in its
independence from time or temporal variations, and it is immutable in
that once God wills the world, things never change in respect to their
substance but only in respect to their modes of being. Although we
must wait to know what things God actually created, we are guaranteed
of the truth of our ideas since it is the object itself that
determines what we perceive. Truth is necessary in that God gives all
objects He creates an irrevocable being, but it is contingent in
relation to His absolute and unlimited power. God is the equal author
of the essence and the existence of things He created, He
"... gave them their essence and their existence which are
equally contingent, and which once received, are nevertheless
possessed by them irrevocably" (OPD 6, 249). Desgabets's
voluntarism, then, is a qualified one, for though the eternal truths
depend upon God for their existence as their primary cause, they are
no less indefectible, that is, they are unchangeable in their
substantial being. Moreover, eternal truths discovered by us are true
and necessary since God chose to create things in such a way that once
created his will could not be undone.



The tenets that Desgabets drew from the Creation Doctrine show us
where Desgabets parts ways with Descartes on many points. For example,
Descartes erroneously concludes in Meditation V that essences, such as
the true and immutable nature of a triangle, can exist separately from
material existence as a purely possible being. According to
Desgabets's strict adherence to the Creation Doctrine,
"... objects precede truth in the order of nature,"
such that, "... it is impossible that there be a triangle
separate from its existence, or that the whole be greater than its
part if there is no whole or parts, which is to say in a word, that
our principle is found yet more true, and it is impossible to think of
nothing" (OPD 6, 232). The Creation Doctrine also grounds
Desgabets's treatment of the senses as the foundation of all
knowledge, and his view that the substances are indefectible. Although
at times elusive, the unity of Desgabets's thought can be seen
in his defense of the Creation Doctrine.



To conclude, when we view Desgabets's work as a whole, there is
no doubt that what he viewed as a revision or perfection of the
Cartesian philosophy others have viewed as a fundamental departure. In
his favor, he never strayed from the Cartesian metaphysics of
substance dualism, substance-mode ontology, mind-body union and
interaction, and the view that extension is the essence of matter and
thought the essence of mind. He remained loyal to the Cartesian
physics against the atomists. Moreover, and perhaps heretically to
some, he strongly rejected the rationalist epistemology which often
dominates in Descartes, and argued that Descartes's own
principles favor a sensory foundation for knowledge. By
Desgabets's own lights, he remained loyal to the Cartesian
principles: "I will establish his reputation upon eternal
foundations by giving his philosophy its expected reputation. For, it
has to be known that his philosophy, once purged of certain errors and
having received the vast scope possible to it, must pass for the
masterpiece of the human spirit, and for what is the greatest of its
kind in the world" (OPD 5, 152).