19 Dec 2008

"What Can a Body Do?" Power of Affection in Spinoza and Deleuze

[The following is quotation up to the Deleuze section, which is summary. My commentary is in brackets. The final quotation is the section where Deleuze obtains his famous question, "What can a body do?" (Qu'est-ce que peut un corps?) Preceding that are the sections that Spinoza cites in that final quotation.]

Baruch Spinoza


Part II

Proposition 6

Prop. VI. The modes of any given attribute are caused by God, in so far as he is considered through the attribute of which they are modes, and not in so far as he is considered through any other attribute.

((Other versions:
The modes of each attribute have God as a cause in so far as he is considered only under that attribute of which they are modes, and not in so far as he is considered under any other attribute.
(Parkinson 117)


Cujuscunque attributi modi Deum, quatenus tantum sub illo attributo, cujus modi sunt, & non, quatenus sub ullo alio consideratur, pro causa habent.))

[For example, God considered in terms of extension cannot be thought to be the cause of an idea, only God conceived in terms of thought can be considered the cause of an idea.]

Part II

Definition 1

Definition I. By body I mean a mode which expresses in a certain determinate manner the essence of God, in so far as he is considered as an extended thing.

((By body I understand a mode which expresses in a certain and determinate way the essence of God, in so far as he is considered as an extended thing.
(Parkinson 113)

I. Per corpus intelligo modum, qui Dei essentiam, quatenus, ut res extensa, consideratur, certo, & determinato modo exprimit.))

[The body is a mode of the attribute of extension, hence the body expresses the divine substance's extensivity, which is infinite because God is infinite, hence the body expresses God's infinity (also because the body implicates the infinity of all parallel attributes).]

Part II

Proposition 2

Prop. II. Extension is an attribute of God, or God is an extended thing.

((Extension is an attribute of God, or, God is an extended thing.
(Parkinson 115)


Extensio attributum Dei est, sive Deus est res extensa.))

Part II

Proposition 12

Prop. XII. Whatsoever comes to pass in the object of the idea, which constitutes the human mind, must be perceived by the human mind, or there will necessarily be an idea in the human mind of the said occurrence. That is, if the object of the idea constituting the human mind be a body, nothing can take place in that body without being perceived by the mind.

((Whatever happens in the object of the idea constituting the human mind must be perceived by the human mind, or, there will necessarily exist in the human mind an idea of this thing. That is, if the object of the idea constituting the human mind is a body, nothing can happen in that body which is not perceived by the mind.
(Parkinson 123-124)


Quicquid in objecto ideæ, humanam Mentem constituentis, contingit, id ab humana Mente debet percipi, sive ejus rei dabitur in Mente necessario idea: Hoc est, si objectum ideæ, humanam Mentem constituentis, sit corpus, nihil in eo corpore poterit contingere, quod a Mente non percipiatur.))

[Here we are dealing with the mind of a human, which is a mode. Our bodies are our modalities in Extension, our mind's are our modalities in Thought. To every mode belongs parallel modes in the infinity of other attributes. The parallel to the body is our mind. Our mind is an idea of the body. So on account of this parallelism, whatever happens to the body must be perceived by the mind, because an affection of one would parallel a corresponding affection in the other attribute.]

Part II

Proposition 49

Prop. XLIX. There is in the mind no volition or affirmation and negation, save that which an idea, inasmuch as it is an idea, involves.

((There is in the mind no volition, or, no affirmation and negation, apart from that which an idea involves in so far as it is an idea.
(Parkinson 156)


In Mente nulla datur volitio, sive affirmatio, & negatio præter illam, quam idea, quatenus idea est, involvit.))

[For example, when we consider the idea of a triangle, we thereby affirm that its three angles equal two right angles, because we cannot conceive a triangle without also affirming this fact about it.]

What Can a Body Do?

[Following quotations from the Elwes translation only]

Part III

Proposition 2

Prop. II. Body cannot determine mind to think, neither can mind determine body to motion or rest or any state different from these, if such there be.

[There is no causation of a mode in one attribute to a mode in another attribute.]

Proof.-All modes of thinking have for their cause God, by virtue of his being a thinking thing, and not by virtue of his being displayed under any other attribute (II. vi.). That, therefore, which determines the mind to thought is a mode of thought, and not a mode of extension ; that is (II. Def. i.), it is not body. This was our first point. Again, the motion and rest of a body must arise from another body, which has also been determined to a state of motion or rest by a third body, and absolutely everything which takes place in a body must spring from God, in so far as he is regarded as affected by some mode of extension, and not by some mode of thought (II. vi.) ; that is, it cannot spring from the mind, which is a mode of thought. This was our second point. Therefore body cannot determine mind, &c. Q.E.D.

Note.-This is made more clear by what was said in the note to II. vii., namely, that mind and body are one and the same thing, conceived first under the attribute of thought, secondly, under the attribute of extension. Thus it follows that the order or concatenation of things is identical, whether nature be conceived under the one attribute or the other ; consequently the order of states of activity and passivity in our body is simultaneous in nature with the order of states of activity and passivity in the mind. The same conclusion is evident from the manner in which we proved II. xii.

Nevertheless, though such is the case, and though there be no further room for doubt, I can scarcely believe, until the fact is proved by experience, that men can be induced to consider the question calmly and fairly, so firmly are they convinced that it is merely at the bidding of the mind, that the body is set in motion or at rest, or performs a variety of actions depending solely on the mind’s will or the exercise of thought. However, no one has hitherto laid down the limits to the powers of the body, that is, no one has as yet been taught by experience what the body can accomplish solely by the laws of nature, in so far as she is regarded as extension. No one hitherto has gained such an accurate knowledge of the bodily mechanism, that he can explain all its functions ; nor need I call attention to the fact that many actions are observed in the lower animals, which far transcend human sagacity, and that somnambulists do many things in their sleep, which they would not venture to do when awake : these instances are enough to show, that the body can by the sole laws of its nature do many things which the mind wonders at.

Again, no one knows how or by what means the mind moves the body, nor how many various degrees of motion it can impart to the body, nor how quickly it can move it. Thus, when men say that this or that physical action has its origin in the mind, which latter has dominion over the body, they are using words without meaning, or are confessing in specious phraseology that they are ignorant of the cause of the said action, and do not wonder at it.

But, they will say, whether we know or do not know the means whereby the mind acts on the body, we have, at any rate, experience of the fact that unless the human mind is in a fit state to think, the body remains inert. Moreover, we have experience, that the mind alone can determine whether we speak or are silent, and a variety of similar states which, accordingly, we say depend on the mind’s decree. But, as to the first point, I ask such objectors, whether experience does not also teach, that if the body be inactive the mind is simultaneously unfitted for thinking? For when the body is at rest in sleep, the mind simultaneously is in a state of torpor also, and has no power of thinking, such as it possesses when the body is awake. Again, I think everyone’s experience will confirm the statement, that the mind is not at all times equally fit for thinking on a given subject, but according as the body is more or less fitted for being stimulated by the image of this or that object, so also is the mind more or less fitted for contemplating the said object.

But, it will be urged, it is impossible that solely from the laws of nature considered as extended substance, we should be able to deduce the causes of buildings, pictures, and things of that kind, which are produced only by human art ; nor would the human body, unless it were determined and led by the mind, be capable of building a single temple. However, I have just pointed out that the objectors cannot fix the limits of the body’s power, or say what can be concluded from a consideration of its sole nature, whereas they have experience of many things being accomplished solely by the laws of nature, which they would never have believed possible except under the direction of mind : such are the actions performed by somnambulists while asleep, and wondered at by their performers when awake. I would further call attention to the mechanism of the human body, which far surpasses in complexity all that has been put together by human art, not to repeat what I have already shown, namely, that from nature, under whatever attribute she be considered, infinite results follow. As for the second objection, I submit that the world would be much happier, if men were as fully able to keep silence as they are to speak. Experience abundantly shows that men can govern anything more easily than their tongues, and restrain anything more easily than their appetites ; when it comes about that many believe, that we are only free in respect to objects which we moderately desire, because our desire for such can easily be controlled by the thought of something else frequently remembered, but that we are by no means free in respect to what we seek with violent emotion, for our desire cannot then be allayed with the remembrance of anything else. However, unless such persons had proved by experience that we do many things which we afterwards repent of, and again that we often, when assailed by contrary emotions, see the better and follow the worse, there would be nothing to prevent their believing that we are free in all things. Thus an infant believes that of its own free will it desires milk, an angry child believes that it freely desires vengeance, a timid child believes that it freely desires to run away ; further, a drunken man believes that he utters from the free decision of his mind words which, when he is sober, he would willingly have withheld : thus, too, a delirious man, a garrulous woman, a child, and others of like complexion, believe that they speak from the free decision of their mind, when they are in reality unable to restrain their impulse to talk. Experience teaches us no less clearly than reason, that men believe themselves to be free, simply because they are conscious of their actions, and unconscious of the causes whereby those actions are determined ; and, further, it is plain that the dictates of the mind are but another name for the appetites, and therefore vary according to the varying state of the body. Everyone shapes his actions according to his emotion, those who are assailed by conflicting emotions know not what they wish ; those who are not attacked by any emotion are readily swayed this way or that. All these considerations clearly show that a mental decision and a bodily appetite, or determined state, are simultaneous, or rather are one and the same thing, which we call decision, when it is regarded under and explained through the attribute of thought, and a conditioned state, when it is regarded under the attribute of extension, and deduced from the laws of motion and rest. This will appear yet more plainly in the sequel. For the present I wish to call attention to another point, namely, that we cannot act by the decision of the mind, unless we have a remembrance of having done so. For instance, we cannot say a word without remembering that we have done so. Again, it is not within the free power of the mind to remember or forget a thing at will. Therefore the freedom of the mind must in any case be limited to the power of uttering or not uttering something which it remembers. But when we dream that we speak, we believe that we speak from a free decision of the mind, yet we do not speak, or, if we do, it is by a spontaneous motion of the body. Again, we dream that we are concealing something, and we seem to act from the same decision of the mind as that, whereby we keep silence when awake concerning something we know. Lastly, we dream that from the free decision of our mind we do something, which we should not dare to do when awake.

Now I should like to know whether there be in the mind two sorts of decisions, one sort illusive, and the other sort free? If our folly does not carry us so far as this, we must necessarily admit, that the decision of the mind, which is believed to be free, is not distinguishable from the imagination or memory, and is nothing more than the affirmation, which an idea, by virtue of being an idea, necessarily involves (II. xlix.). Wherefore these decisions of the mind arise in the mind by the same necessity, as the ideas of things actually existing. Therefore those who believe, that they speak or keep silence or act in any way from the free decision of their mind, do but dream with their eyes open.

Gilles Deleuze

Expressionism in Philosophy


"What Can a Body Do?"

The first expressive triad of modality is:
1) an essence as a degree of power
2) a characteristic relation in which that degree of power expresses itself
3) the extensive parts subsumed under this characteristic relation

In the Ethics there is system of equivalences producing a second expressive triad:
1) the essence as a degree of power
2) a certain capacity to be affected in which it expresses itself
3) the affection that, each moment, exercises that capacity
(196b/217b) [Citations give French version first, followed by English.]

Each extensive mode is made up of a great number of extensive parts, and all parts from every mode affect one another ad infinitum, hence all existing modes are affected in many diverse ways.

Modes have affections in accordance with their "certain capacity of being affected" (un certain pouvoir d'être affecté). Different creatures -- horses, fish, even different individual humans -- are each affected by different things and in different ways.

Modes cease existing when they no longer are capable of maintaining their characteristic relations, which occurs when the mode is no longer able to be affected in many ways. Thus, modal relations go hand-in-hand with the capacity to be affected, so the questions What is the structure of a body? and What can a body do? are equivalent questions, because "what a body can do corresponds to the nature and limits of its capacity to be affected (ce que peut un corps, c'est la nature et les limites de son pouvoir d'être affecté).

On account of God's infinite power (potentia), he has the capacity (potestas) to be affected in an infinity of ways.

The mode's capacity to be affected in many ways is "always exercised under the action of external modes" (toujours nécessairement rempli sous l'action des modes extérieurs.) (198c/218c)

Although the very great number of ways that a finite mode may be affected is an infinity, it is a greater or lesser infinity relating to something finite. The infinity of ways that God is affected (on account of his affections being self-caused and not externally conditioned) is an unlimited infinity comprising all the essences of modal existences. (198c/218c.d)

Affections are not sufferings or passions.

Affections that can be completely explained by the nature of the affected body are active affections, and themselves actions.

Si nous supposons des affections qui s'expliquent entièrement par la nature du corps affecté, ces affections sont actives, sont elles-mêmes des actions.

So because there are no causes external to God, he then is the cause of all his affections, thus all his affections are explained by his own nature, and for this reason all of God's affections are active.

Not so with existing modes, which do not exist by virtue of their own nature, because "their existence is composed of extensive parts that are determined and affected from outside, ad infinitum" (leur existence est composée de parties extensives qui sont déterminées et affectées du dehors, à l'infini) (199a/219b). So because the sources of modal affections are exterior, they tend to be passions.

Spinoza's ethical question is, can finite modes such as ourselves attain to active affections, and if so, how do they do so?

When God is affected, a mode is produced. But when a mode is affected, there is a second degree of affection, an affection of an affection. When some body has an effect on us, there is a passive affection. The idea of such an affection does not express its cause, but instead indicates our body's present condition, thereby exercising our capacity to be affected. The bodily affection is a corporeal image, and the idea of the affection in our mind is an inadequate idea, an imagining.

What flows from the ideas of affections are another sort of affections: affects (affectus) or feelings. (199bc-200a/219c-220ab) Our body undergoes duration, hence its present state is inseparable from its previous state, both linked together in continuous duration. Because the ideas we have indicate the present state of our body's constitution, every idea is linked to another idea indicating an earlier state of the body. Our feelings are ideas that concretely relate present and past in a continual duration. (200a.b/220b.c)

There are thus two sorts of modal affections:
1) states of a body or ideas indicating these states, and
2) changes in the body or ideas indicating these changes.

When we begin existence, we have passive feelings (passions) and thus inadequate ideas.

When we have an idea that cannot be formally explained as a product of our power of understanding, then we are not the cause of the idea, and the idea is inadequate. This inadequate idea causes a feeling, then, that we did not cause and is thus a passion. (200d/220-221)

Our capacity to be affected is thus exercised, from the beginning of our existence, by inadequate ideas and passive feelings.

Notre pouvoir d'être affecté se trouve donc rempli, dès le début de notre existence, par des idées inadéquates et des sentiments passifs.

Moreover, adequate ideas and active feelings are likewise linked. When we are the cause of an idea, it is adequate, thus we are also the cause of the idea's corresponding feeling. Such a feeling that we cause is an action. So when our mind has adequate ideas, we do certain things; and when we have inadequate ideas, we undergo certain things. The ethical question is a methodological question of how we are to become active, which is to ask, "how can we produce adequate ideas?" (201b/221c)

As the mode undergoes passive affections, its capacity to be affected appears as a force or power of suffering (force ou puissance de pâtir). The mental equivalent of the body's power of suffering is power of imagining and of experiencing passive feelings. (201d/212-222)

But regardless of how much one is being passively or actively affected, one's capacity to be affected remains constant. And active and passive affections are in an inversely proportional relationship: when we produce active affections, our passive ones decrease. (202a/222b.c)

And yet, our capacities to be affected vary as well, because a mode's composition and decomposition passes through many stages, so we might even say that when we grow out of childhood, we change our body or relation. Is who we are as an infant the same as when we are a full adult, and also the same when we are at our eldest age? As we undergo these changes, so too changes our capacities to be affected. Let's consider the example from Deleuze's footnote 15:

Ethics Part IV, 39, scholium:

I would here remark that I consider that a body undergoes death, when the proportion of motion and rest which obtained mutually among its several parts is changed. For I do not venture to deny that a human body, while keeping the circulation of the blood and other properties, wherein the life of a body is thought to consist, may none the less be changed into another nature totally different from its own. There is no reason, which compels me to maintain that a body does not die, unless it becomes a corpse ; nay, experience would seem to point to the opposite conclusion. It sometimes happens, that a man undergoes such changes, that I should hardly call him the same. As I have heard tell of a certain Spanish poet, who had been seized with sickness, and though he recovered therefrom yet remained so oblivious of his past life, that he would not believe the plays and tragedies he had written to be his own : indeed, he might have been taken for a grown-up child, if he had also forgotten his native tongue. If this instance seems incredible, what shall we say of infants? A man of ripe age deems their nature so unlike his own, that he can only be persuaded that he too has been an infant by the analogy of other men. However, I prefer to leave such questions undiscussed, lest I should give ground to the superstitious for raising new issues.

Deleuze says that both our capacity to be affected as well as our characteristic relation "enjoy a margin, a limit, within which they take form and are deformed" (jouissaient d'une marge, d'une limite dans laquelle ils se forment et se déforment) (202d/222-223). Hence we see, says Deleuze, the significance of Spinoza's letter to Meyer where he describes infinities of differential variation within maxima and minima [see entries on Spinoza's Letter on Infinity, Hegel's commentary, Gueroult's commentary, and Deleuze's commentary] [Also note Deleuze's term "deformed:" we will see in his aesthetics that the intensity of sensation results from deformation, in subtle contrast to transformation.]

But powers to act and to suffer are only inversely related when we conceive of affection abstractly. Leibniz was influenced by Spinoza's theory of affection, and wonders if passive force should be considered distinct from active force. What distinguishes them is that active forces are real, positive, and affirmative; whereas passive forces assert and express nothing except the imperfection of the finite. Active force is autonomous, passive ones are not, because passive forces are merely the limitations of active forces; hence there would be no passive force were it not for the active force that it limits. Passive forces are limitations as well of an even deeper force, which is the essence asserting and expressing itself solely inactive forces. (203a.d/223a-224)

So the power of suffering does not express anything that is positive, because there is always something imaginary in passive affections which prevents them from being real.

We are passive and impassioned only by virtue of our imperfection, in our imperfection itself.

Nous ne sommes passifs et passionnés qu'en raison de notre imperfection, par notre imperfection même.

The agent of the action acts through what he is in possession-of, and the patient of an action suffers through what he lacks. But our passive force is merely the limitation of our active force, and hence it asserts nothing, because it expresses nothing. It merely "involves" (enveloppe) our impotence (impuissance), which is the limitation on our power of action; it is the lowest degree of our power of acting (le plus bas degré de notre puissance d'agir). (204c.d/224c.d)

Only active affections are really able to positively exercise our capacity to be affected. Our power of action, which is our capacity to be affected, expresses our essence, which is the same as our power of action. (205a/225b)

Spinoza reconciles two fundamental principles:
1) From the physical view: An essence's capacity to be affected remains fixed, regardless of whether active or passive affections exercise that capacity. So because the essence's capacity remains fixed, no matter the affection, modes are always as perfect as they can be.
2) From the ethical view: An essence's power of being affected is fixed, but fixed within minimum and maximum limits. When passive affections exercise their power of being affected, then that power is reduced to the minimum. This leaves the mode imperfect and impotent, and cut-off from its essence or degree of power, that is to say, it cuts us off from what we can do.

So a mode is always as perfect as it can be, but its perfection is relative to those affections that actually belong to the modal essence. [So given certain circumstances, our essence's capacity to be affected decreases, thus it cannot be expected to have more power at that moment. The stone cannot be expected to see.]

So the mode undergoes expressive changes, because its changes in power are changes in the mode of substance's self-expression of its infinite power. There is a vast network of modes acting on each other, that is, affecting each other; these are the mechanical changes the mode undergoes. Also, the essence itself changes. As we grew from child to adult, our essence changed as well. What changed was our capacity to be affected; these are "metaphysical" changes of the essence itself, stemming from whatever affections belong to the mode while it exists. So while we exist, our essence itself varies with us, which should be expected, because essences lie along an indivisible continuum of variation of degrees of power. Thus our essences vary, but between a maximum and minimum of variation. So two things are eternal or fixed in regard to essences: their limits of variation, and their perfection at any given time of existence. (205b.d/225b-226)

So we see then the importance of Spinoza's ethical question, the point of which can be formulated two ways:
1) We do not even know of what a body is capable,
2) We do not even know of what affections we are capable, nor the extent of our power.

So during our existence, our essence's power of affection will reach both its minimum and maximum. But we are finite beings with limited knowledge even of ourselves. So at any given time, we cannot know whether or not we are at our maximum, because we cannot know if other modes might affect us in such a way as to increase our power later.

But Deleuze suggests that we can try to become concretely active, so that we can know our maximum of power.

[Yet Spinoza is still a determinist. If we endeavor to become more active, we were determined exteriorly to do so. But so what? If while I am striving to become more active, (which would mean more rational), it should not matter to me if there are forces acting on me compelling me to do so. And is this not our experience anyway? Are we not the most driven to action when some extraordinary force compels us, almost as though we had no choice? Hence Deleuze does not say that we should try to become concretely active so that we can become our maximum. Again, we are finite modes who cannot know what our essence's capacities are; we can only know it once we reach it, and even then we cannot know it for sure.

Herman De Dijn offers the example of his daughter returning home past curfew. He stays-up waiting and worrying, increasingly becoming angry. When she arrives, he begins yelling and scolding, but his daughter explains that she blew her bicycle tire on her way home. De Dijn was passively affected to have passions of anger, but even knowing the cause of his daughter's lateness does not make him stop being angry all at once.

He could also think rationally about his affections. He might think to himself, "when I am forced to worry about my daughter's well being, I become passionate." Knowing the cause of his anger, that is, thinking rationally about his anger also will not make it go away, but it makes it better, because he knows that the cause is exterior, and he better knows what that exterior cause is. His very knowing the cause is an active affection, he knows more his own ways of being affected. This does not change the way things are affecting him at that time, but it maximizes his essence's power (of being affected).

So our striving for active affection should be a rational affair; we should strive to be active by learning and reasoning what affections cause our essence's power to increase (similarly to how De Dijn learned which affections cause them to decrease). So by knowing rationally the ways we are affected, we are thereby striving to be more active, which allows us to experience a higher degree of power.]

Deleuze, Gilles. Spinoza et le problème de l'expression. Paris: Les Éditions de Minuit, 1968.

Deleuze, Gilles. Expressionism in Philosophy: Spinoza. Trans. Martin Joughin. New York: Zone Books, 1990.

Spinoza. Ethics. Ed. & Transl. G.H.R. Parkinson. Oxford: Oxford University Press, 2000.

Spinoza. Ethics. Transl. Elwes. available online at:


Spinoza. Ethica. available online at:


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  1. A great post.. that I will read soon, and no doubt just open up more and more angles and directions to travel by.

  2. Thanks, I really appreciate you taking a look at it. I am returning to this work on Spinoza and Body, so it was great to see your comment and look once again at the material. Take care! Corry