Illusion in Du Châtelet's Theory of Happiness

I. Introduction

The focus of Émilie Du Châtelet’s Discourse on Happiness is the exposition and defense of five necessary conditions for happiness: ‘In order to be happy, one must have freed oneself from prejudices, one must be virtuous, healthy, have tastes and passions, and be susceptible to illusions; for we owe most of our pleasures to illusions, and unhappy is the one who has lost them’ (2009a: 349).¹ Most of these conditions are, if not uncontroversial, at least unsurprising; freedom from prejudice, virtue, health, and passions were often thought to be required for happiness. However, the fifth condition, which states that susceptibility to illusion is required for happiness (hereafter ‘the illusion condition’), was not. Indeed, it appears to be completely original to Du Châtelet.² Curiously, she hardly defends the illusion condition in the Discourse; in fact, she claims that it ‘scarcely needs to be proved’ (2009a: 354).³ Although original, she apparently thought it was obvious.

Du Châtelet does offer a few examples of illusions in the Discourse, but on their own they offer very little support to the illusion condition. Her first example is of ‘spectacles’ like puppet shows, theater, and opera: ‘Would we have a moment of pleasure at the theater if we did not lend ourselves to the illusion that makes us see famous individuals that we know have been dead for a long time, speaking in Alexandrine verse?’ (2009a: 354–55). Without illusions, she claims we would not be able to enjoy spectacles, because we would see them for what they are, rather than for what they represent. Her other two examples of illusion are in the passions of glory and love. Concerning glory, she claims that we can enjoy our reputation more if we believe ourselves and our accomplishments to be more recognized than they actually are, by imagining ourselves to be praised by posterity (2009a: 357–58). Concerning love, she claims we can enjoy even unrequited love by imagining ourselves to be loved by one who in reality does not love us. Here she cites her relationship with Voltaire, claiming that ‘I was loving for two, I spent all my time with him, and my heart, free from suspicion, delighted in the pleasure of loving and in the illusion of believing myself loved’ (2009a: 362). On their own, these three examples do not provide an adequate defense of the illusion condition. Even granting that hedonism is true (as Du Châtelet believed—see section II), it seems that one could be happy without pleasures from unrequited love, the plaudits of posterity, and spectacles. There are plenty of other pleasures to go around; one should not require these three.

Aware of this problem, Du Châtelet claims that while she gives but a few examples, ‘we owe most of our pleasures to illusions’ (2009a: 349), and ‘[illusion] is mixed up with all the pleasures of our life’ (2009a 355/1961: 15–6).⁴ Illusion is thus necessary for happiness because it is required in order to experience the pleasures that are necessary for happiness. The problem with this justification, however, is that Du Châtelet does not give a theory of illusion that explains what illusions are and how illusions are ‘mixed up with’ most or all of our pleasures. Without a general theory of illusion present in the Discourse, Du Châtelet’s illusion condition does not appear to be adequately justified.

An additional problem suggested by Du Châtelet’s endorsement of the illusion condition is discussed in a recent article by Lascano (2021: 1–4; 11–7). Both in the Discourse and elsewhere, Du Châtelet insists that we ought not to be susceptible to error. Examples of error include false judgments in science and religion, as well as other prejudices. However, it is not clear how Du Châtelet can make a distinction between illusion, which she recommends, and error, which she does not. Again, Du Châtelet is aware of this problem. Her response is to claim that illusions are not errors, because while they misrepresent, they are similar to sensory illusions in that they do not wholly misrepresent objects, but only ‘[adjust] them to our nature’ (2009a: 354). She does not, however, offer an account of illusion that explains why the illusions we need for happiness are similar to sensory illusions. So, without a general theory of illusion, the distinction between illusion and error also lacks justification. The reader is left to wonder what illusions are and where they come from, and without this information, her entire theory of the role of illusion in happiness appears to stand on shaky ground.

In this paper, I will argue that although it is not in plain sight, there is a general theory of illusion beneath the surface of the Discourse, which explains what illusions are, what causal role they play in making us happy, and why they are distinct from errors. I argue that the illusions of the Discourse are the misrepresentative byproducts of the passions in the imagination. This theory (called the theory of passionate misrepresentation, or TPM) is easy to overlook given that Du Châtelet never explicitly formulates it in the Discourse or anywhere else in her corpus. Instead, it appears in the work of other influential French philosophers, including Descartes, Malebranche, and Anne Thérèse, Marquise de Lambert. Understood in the context of this tradition, I argue that Du Châtelet avoids both of the problems sketched above. The support for her illusion condition and her claim that illusion is different from error comes from the widely accepted theory of illusion that is found in TPM. Framed in this way, the illusion condition appears to be not only original but also adequately justified and persuasive.

I proceed as follows. Sections II-V concern the first problem: that Du Châtelet’s illusion condition appears to lack justification. I begin in section II by explaining a general strategy for justifying the illusion condition. Illusions must be shown to be something without which one would ordinarily fail to attain the pleasures required for happiness. In sections III and IV, I explain TPM. Key to my interpretation is the claim that the passions necessarily cause illusions and that illusions are necessary for sustaining and intensifying the passions. Because passions are necessary for achieving the pleasures we need to be happy, and illusions are necessary for robust passions, illusions are also necessary for happiness. In section V, I show how TPM coheres with Du Châtelet’s own examples of illusion in the Discourse. Section VI tackles the second problem, arguing that if we understand illusions to be passionate misrepresentations, we gain an explanation of why Du Châtelet thinks illusions are distinct from errors. Section VII concludes by considering how despite agreeing with tradition by accepting TPM, Du Châtelet offers a very different theory of happiness than that offered by the neo-Stoics and in particular, by Malebranche.

II. Necessary Conditions for Happiness

At the outset, it must be clarified in what sense Du Châtelet thinks that health, virtue, illusion, and the like are necessary for happiness. Du Châtelet’s strategy follows her hedonism;⁵ in justifying the necessary conditions for happiness, she routinely appeals to the fact that these things cause pleasure.⁶ The following condition gives a rough approximation of her understanding of a necessary condition for happiness:

Happiness

x is necessary for happiness if, without x, the aggregate of one’s pleasures and pains could not reach the threshold for happiness.

One might argue that this interpretation makes Du Châtelet’s necessary conditions for happiness implausible. The objection goes like this: for any of the conditions that Du Châtelet identifies as necessary for happiness, each will inevitably fail to satisfy happiness on intuitive grounds. For instance, if health is to be a necessary condition for happiness, then it must be the case that in any possible circumstance where one lacks health, the aggregate of their pleasure/pain must fail to reach the threshold for happiness. However, we can easily conceive of a rather ill person who, despite her illness, is the subject of immense physical and emotional pleasures, so much so that the aggregate intensity of her pleasures outweighs to a sufficient extent the aggregate intensity of the pains of her illness. But then we have a counterexample that shows that health does not satisfy happiness. The same sorts of counterexamples can be constructed for the other necessary conditions that Du Châtelet identifies. In fact, this problem threatens to undermine the possibility of any necessary condition on happiness that is interesting and non-trivial, since for any candidate necessary condition, we are likely able to conceive of a counterexample by imagining a circumstance where the person lacks x but nevertheless possesses an immense quantity of intense pleasures.

This objection brings out an important point about Du Châtelet’s methodology in the Discourse, which in turn can be deployed to address the objection. The objection assumes that the relevant notion of necessity and possibility is conceptual; that is, for x to be necessary for y, it must be conceptually impossible for y to obtain without x. However, Du Châtelet appears to be deploying a different notion of possibility in the discourse. The tone of the Discourse is rather advisory than analytical; her goal is not so much to provide an analysis of the concept of happiness as to offer practical advice to those pursuing happiness.⁷ As such, she does not describe logically necessary conditions for happiness, but rather conditions without which one could not reasonably expect to be happy, even if in some situations one could still be happy without these things. I therefore suggest we take the following as a guide:

Practical Necessity

x is practically necessary for y if in ordinary circumstances, without x, y is unlikely to obtain.

We can update happiness to incorporate practical necessity:

Happiness*

x is necessary for happiness if in ordinary circumstances,⁸ without x, the aggregate of one’s pleasures and pains are unlikely to meet the threshold for happiness.⁹

We therefore avoid the above objection; whatever is providing tremendous pleasure despite the illness makes the situation less ordinary, and ordinarily in a state of illness one would be unlikely to achieve the requisite pleasures for happiness. A plausible case can be made that virtue, health, passions, and the like are practically necessary for happiness, even if in some circumstances one may not need them to be happy. The question now is why Du Châtelet thinks that in ordinary circumstances, we are very unlikely to attain happiness if we do not have illusions. To this we now turn.

III. The Theory of Passionate Misrepresentation

Understanding Du Châtelet’s illusions as misrepresentations of the passions, I believe, is the key to understanding why she thinks that without illusions, we are very unlikely to attain happiness. The view that the passions misrepresent their objects traces back at least to the Stoics,¹⁰ and was later accepted by Descartes and Malebranche, who offer a novel mechanistic psycho-physiological explanation of the misrepresentative effects of the passions. In the French tradition, these misrepresentations of the passions eventually are referred to as ‘illusions’, as seen in the work of Anne-Thérèse, Marquise de Lambert. It is my view that when Du Châtelet refers to illusions in the Discourse, she means to refer to passionate misrepresentations from this tradition.

In the Passions of the Soul and the Correspondence with Elisabeth, Descartes claims that the passions almost always produce misrepresentations in the mind of the person experiencing the passion:

But often passion makes us believe that certain things are much better and more desirable than they are….[T]here are [no passions] which do not represent to us the good to which they tend more vividly than is merited and which do not make us imagine pleasures much greater before we possess them than we find them afterward, once we have them. (2007: 108)

[T]he passions almost always cause the goods they represent, as well as the evils, to appear much greater and more important than they are. (1985a: 377)

For Descartes, the passions act upon the imagination to give false appearances to the mind. In these passages, he acknowledges four ways that objects can appear differently than they actually are as a result of the passions: goodness, desirability, greatness, and importance. Though Descartes seems to allow that it might be possible that a passion might not always misrepresent its object, nevertheless insofar as one has passions, one likely will be susceptible to their misrepresentative effects.

Although Descartes describes the misrepresentative effects of the passions, he never uses the term ‘illusion’ to describe these misrepresentative states. The same is largely true of Malebranche, who most commonly uses the term ‘illusion’ to describe errors related to the senses, without designating any particular term for errors related to the passions.¹¹ However, in one passage where he discusses the passion of wonder, Malebranche does refer to a passionate misrepresentation as an illusion:

there is a great danger that his [passion of] wonder, which shows him these sciences [of poetry, chemistry, or history] only in their best light, will seduce him. It is even to be feared that it will so corrupt his heart that he will be no longer able to give up his illusion, although he may recognize it as such later on, because the deep traces engraved in his brain by continuous wonder cannot be erased. This is why he must always guard the purity of his imagination, i.e., he must prevent these dangerous traces that corrupt the mind and heart from being formed in the brain. (1980: 388)¹²

Malebranche calls an ‘illusion’ the misrepresentation caused by the passion of wonder. The passage further implies that illusions of this sort are caused by engraved brain traces, and are thus products of the imagination.

That the term ‘illusion’ later came to be the primary term for describing the misrepresentations of the passions can be seen in the work of the salonnière Anne-Thérèse, Marquise de Lambert. Lambert’s salon in Paris was the premiere gathering place for French intellectuals in the early eighteenth century, and her works were widely circulated and discussed among patrons of her salon. Pirated editions of her works, including New Reflections on Women, were published in the late 1720s, around the time the young socialite Du Châtelet was in Paris.¹³ This led Lambert to reluctantly publish official versions of these works shortly after.¹⁴ Lambert defines the term ‘illusion’ as follows: ‘Illusion is a sentiment which transports us beyond the truth, by obscuring our reason. You see in the persons that begin to please you, every perfection; and the imagination, which always acts under the dominion of the heart, lends to the beloved object the merit which it wants’ (1780: 47). According to Lambert, illusions are effects of the imagination that obscure our reason, as occurs in the beginning of friendship, when one imagines the friend to have more merit than they in fact do. Since friendship is due to the passion of love (see section IV for further detail), Lambert’s claim here establishes a connection between the passion of love and the illusion of believing a person to be better than they actually are. In New Reflections on Women, Lambert claims more generally that the passions cause illusions: ‘The imagination is the source and guardian of our pleasures. It is solely responsible for the agreeable illusion of the passions (l’agréable illusion des passions). Always a willing accomplice of the heart, it furnishes it with all the errors (erreurs) it could wish for’ (1995: 38/1808: 166).¹⁵ This passage occurs directly after she cites Malebranche¹⁶ and bears his unmistakable influence. Important for my purposes is the explicit connection between illusion and the passions.

Descartes, Malebranche, and Lambert’s remarks can be seen as part of what I call the ‘theory of passionate misrepresentation’ (TPM), according to which (1) the misrepresentations of the passions can be called ‘illusions’, and (2) the passions naturally cause illusions. If one has passions, one will therefore be susceptible to illusions. Given the influence of Malebranche and Lambert on eighteenth-century French intellectual culture, Du Châtelet and her audience would have been familiar with such a theory and its core tenets.¹⁷ It therefore must be considered as a candidate for a general theory of illusion that might explain Du Châtelet’s assertion of the illusion condition.

One might think that TPM can already explain why Du Châtelet accepts the illusion condition, because to have passions at all is (necessarily) to be susceptible to their illusions. Since passions are necessary for happiness (2009a: 349), the susceptibility to their misrepresentations must also be necessary for happiness. In the form of an argument:

1. If one has passions, one will be susceptible to misrepresentations of the objects of the passions.

2. A misrepresentation caused by the passions =_df illusion.

3. Therefore, if one has passions, one will be susceptible to illusions.

4. In order to be happy, one must have passions (2009a: 349).

5. Therefore, in order to be happy, one must be susceptible to illusions.

(1) and (2) are the two tenets of TPM delineated above; (3) follows from (1) and (2). (4) is explicitly affirmed by Du Châtelet in the Discourse. So whether or not Du Châtelet would have intended this as an argument for (5), it seems that her acceptance of (1)-(4) could explain why she held (5) to be true. One might then think that by attributing TPM to Du Châtelet, we gain this explanation of why she held that susceptibility to illusion is necessary for happiness.

Promising as it may seem, there is a key problem with this interpretation. It says nothing of whether or not one is happy because of one’s illusions, but rather only that one is happy because of one’s passions. If one lacks illusion in their life, this entails that one would lack happiness only because (by a backtracking counterfactual) it entails that one would lack the passions requisite for happiness. In other words, according to this theory it is the passions that are playing the causal or productive role in making one happy; illusions, on the other hand, are just necessary byproducts of the passions, hardly worth mentioning on their own. This is at odds with Du Châtelet’s own strategy for justifying the place of illusion in the happy life, evidenced in the following two passages:

In order to be happy, one must…be susceptible to illusions; for we owe most of our pleasures to illusions, and unhappy is the one who has lost them. Far then, from seeking to make them disappear by the torch of reason, let us try to thicken the varnish [vernis] that illusion lays on the majority of objects. It is even more necessary to them than are care and finery to our body. (2009a: 349/1961: 4)

I have cited spectacles, because illusion is easier to perceive there. But it is mixed up with [Elle se mêle à] all the pleasures of our life, and it is the varnish [vernis] of life. (2009a: 355/1961: 15–6)¹⁸

To justify the necessity of illusion, Du Châtelet appeals to the causal role that illusions play in the production of most or all of our pleasures, without which life would become drab and unpleasant.¹⁹ If TPM is to explain Du Châtelet’s illusion condition, it must do so by showing that passionate misrepresentations are causally responsible for giving us pleasures that make us happy, and not mere accidental byproducts of the passions. In the next section, I argue that TPM does this, because it holds that illusions play a key role in sustaining and intensifying the passions, without which we would be unable to be happy.

IV. How Illusions Cause the Passions

Malebranche’s account of the passions and their misrepresentations attempts to explain the occurrence of error by examining the psycho-physiological mechanism that produces the passions. According to Malebranche, when the mind perceives an object, the will is immediately determined with regards to this object, followed by a ‘sensation of love, aversion, desire, joy, or sadness’ (1980: 348). If the mind were not united to a material body, the passion would cease here, leaving it weak and languid. However, because our minds occupy human bodies, which are designed to preserve themselves and pursue their own good (survival and health), the passion continues with an involuntary response to the object. There is a ‘determination of the flow of the [animal] spirits and the blood toward the external and internal parts of the body’ in order to ‘give the bearing and motion necessary to acquire the good or flee the evil presenting itself’ (ibid.). In the brain, the flow of the spirits agitates and excites the traces left by the original perception of the object, and it also excites other traces around it. Because what happens in the body is mirrored in the soul, the agitation of the traces in the brain causes us to imagine the object of our perception to be different than we initially perceived it, for we imagine it to be greater than it actually is (due to the vivacity of the perception) or we associate it with other ideas (due to the excitement of the nearby traces). This is how the passions produce false representations in the imagination, i.e. ‘illusions’.

The illusions caused by the passions are not an unlucky byproduct of the passion’s work in the body; rather, Malebranche emphasizes that they serve the important role of strengthening and sustaining the passions. He writes,

The passions all seek their own justification; they unceasingly represent to the soul the object agitating it in the way most likely to maintain and increase its agitation. The judgment or the perception causing the agitation is strengthened to the extent that the passion increases, and the passion increases to the extent that the judgment producing it is in turn strengthened. False judgments and the passions unceasingly contribute to each other’s preservation. (1980: 397)²⁰

The passion and the illusions it causes are in a sort of perpetual loop. The agitation of the brain caused by the movements of the spirits produces an illusion, which in turn redetermines the spirits towards the brain, which re-agitate the fibers, etc. The only way this cycle is interrupted is by the heart, which tires of supplying the spirits necessary for sustaining the passion (ibid.). After the bout of passion has passed, the effects of the illusion are not immediately cured. In agitating traces of the brain during a passion, the spirits actually damage the brain’s fibers: ‘they bend and sometimes even break the brain’s fibers because of their tempestuous flow, leaving the imagination tarnished and corrupt’ (1980: 402). Therefore, the illusion persists long after the passion has subsided on account of the damage to the brain, causing all sorts of erroneous judgments: ‘The passions, then, act on the imagination, and the imagination thus corrupted combats reason by continually representing things to it not as they are in themselves, so that the mind might issue a true judgment, but as they are in relation to the present passion, so that the mind might be led into a favorable judgment of it’ (1980: 402–03). So, on Malebranche’s view, illusions play an important causal role of sustaining and intensifying the passions, both during bouts of passion and long after, through the agitation and degradation of fibers in the brain.²¹

Some examples will serve to illustrate how the passions are sustained and intensified by illusion. Malebranche offers the example of love for a friend:

[We] judge that the cause of our passions, which is often only something imaginary, is really in some object. When we are moved by a passionate love for someone, we judge that everything about him deserves to be loved. His grimaces are pleasant, his ugliness is not offensive, his clumsy and unpolished actions are quite correct, or at least natural. If he never speaks, it is because he is a sage; if he is never silent, it is because he is very intelligent; if he talks about everything, it is because he is a man of great experience; if he continually interrupts others, it is because of his fiery and vivacious nature; if he is always ready to preen himself, it is because he deserves it. This is how passion conceals and disguises our friends’ shortcomings while emphasizing their least advantages. (1980: 370–71)

Malebranche’s discussion implies that the passion of love is strong enough to conceal almost any imperfection through illusion. This concealment serves the purpose of strengthening the passion one has for one’s friend, which in turn leads to further illusion. Malebranche also mentions that this passion can be overturned and turn to hatred:

But if this friendship, which like all passions is based only on the agitation of the blood and animal spirits, begins to cool for lack of bodily heat or spirits to sustain it, or if some distraction or false relation alters the brain’s disposition, the hatred replacing love will not fail to make us imagine all the defects to which we direct our aversion in the object of our passion. We shall then find in this same person qualities just the opposite of those we had admired in him beforehand. We shall be ashamed to have loved him; and the now dominant passion will not fail to justify itself and ridicule the one whose place it has taken. (1980: 371)

In both cases, the illusion works to justify the passion by providing a misrepresentation that sustains it. Without these misrepresentations, the passions would be determined by perceptions of reality, which would fail to strengthen and sustain the passions, leaving us cold and listless.

The same example of love and friendship appears in the work of Lambert:

Friendship, in its infancy, is subject to illusion…Illusion is a sentiment which transports us beyond the truth, by obscuring our reason. You see in the persons that begin to please you, every perfection; and the imagination, which always acts under the dominion of the heart, lends to the beloved object the merit which it wants. We love our friends much more for the qualities that we give them credit for, than for those which they have displayed. (1780: 47–8)²²

The similarities between the two accounts are striking. Lambert explicitly states the dependence of passion upon illusions of the imagination, though unlike Malebranche, she uses the term ‘illusion’ more frequently. Her account of how illusion misrepresents the qualities of our friends whom we love is basically identical. Her work is an almost certain source of inspiration for Du Châtelet’s, for not only does Du Châtelet’s notion of illusion fit well with Lambert’s, but their attitudes towards the value of illusions are also similar. Although Lambert never claims that the illusions of the passions are necessary for happiness, she does not explicitly forbid them, whereas Malebranche is at best ambivalent about the passions and repeatedly warns of their deceptive tendencies.

We can already see how Du Châtelet’s illusion condition would be supported by this feature of TPM. The key is the causal role that illusion plays in sustaining and intensifying the passions. As we have seen, the passions seek their own justification through the production of illusions, which redetermine the flow of spirits associated with the passion in order to strengthen and sustain the body in its passion. In this way, a passion depends on the illusions it creates; without illusions, our passions would never ascend to the heights of which they are capable. Recall happiness*:

x is necessary for happiness if in ordinary circumstances, without x, one’s aggregate pleasures and pains are unlikely to meet the threshold for happiness.

Without illusions, in ordinary circumstances we would in fact be unlikely to reach the threshold for happiness, because our passions would be brief and listless and therefore incapable of producing the many pleasures which are ordinarily required to be happy. One’s friends and loved ones would appear for what they are, flaws and all, and one would hardly be able to love them at all. One’s emotional responses to all objects would be restricted to how they actually appear in perception, rather than how they might be made to appear in imagination. The result is a drab and sad life lacking in passion and pleasure. Given how unlikely one is to reach the threshold level of pleasure needed to be counted as happy without the sustaining and intensifying role of illusion in passion, we can conclude that illusions are practically necessary for happiness.

Earlier, we noted that an explanation of the illusion condition that sees illusions merely as a necessary byproduct of the passions must fail, because it does not account for the causal role illusions play in securing the pleasures necessary for happiness. The explanation on offer here avoids this problem. It is illusion that causes us to have passions in the strength and intensity that we know them. If we were not to have illusions, then we would not be capable of enjoying the many great pleasures of the passions (and this is not a backtracking counterfactual). Therefore, we must have illusions to have these pleasures, and so we must have illusions to be happy.

V. Three Examples of Illusion

We have not yet considered the examples of illusion that Du Châtelet herself provides in the Discourse, which involve the passions of glory and romantic love.²³ In this section, I argue that her own examples reveal two things about her justification for the illusion condition. First, they provide further evidence that Du Châtelet accepted TPM, even though she did not make it explicit. Second, we see that Du Châtelet did not intend for her examples to justify the illusion condition on their own; rather, she intended for them to be a supplement to the familiar examples from the tradition. The illusion condition is therefore better supported than it originally appeared.

According to Du Châtelet, a passion for glory is ‘the source of so many pleasures of the soul, and of so many efforts of all sorts that contribute to the happiness, the instruction, and the perfection of society’ (2009a: 357). It is also, she says, ‘entirely founded upon illusion’ (ibid.). Du Châtelet first introduces the concept of glory when discussing the related passion of study. She claims:

[The] love of study holds within it a passion from which a superior soul is never entirely exempt, that of glory. For half the world, glory can only be obtained in this manner, and it is precisely this half whose education made glory inaccessible and made taste for it impossible…Men have infinite resources for their happiness that women lack. They have many means to attain glory, and it is quite certain that the ambition to make their talents useful to their country and to serve their fellow citizens, perhaps by their competency in the art of war, or by their talents for government, or negotiation, is superior to that which one can gain for oneself by study. But women are excluded, by definition, from every kind of glory, and when, by chance, one is born with a rather superior soul, only study remains to console her for all the exclusions and all the dependencies to which she finds herself condemned by her place in society. (2009a: 357)

Despite recognizing the importance of a passion for glory if one wants to be happy, Du Châtelet also says women are excluded from being glorified by others, because they are not able to show their talents in war, government, or negotiation.²⁴ However, women who are born with ‘superior souls’ can find an outlet for their passion for glory, through the pursuit of study. Although this does not actually lead to being glorified, nevertheless one is able to enjoy one’s passion for glory, because as she explains later, it is possible to enjoy one’s illusions that the passion for glory causes:

The love of glory…is entirely founded on illusion. Nothing is so easy as to make the phantom after which all superior souls run disappear; but there would be much to lose for them and for others! I know there is some substance in the love of glory that one can enjoy in one’s lifetime; but there are scarcely any heroes, of whatever kind, who would want to close themselves off entirely from the plaudits of posterity, from which one expects more justice than from one’s contemporaries. One does not always acknowledge the enjoyment of the ill-defined desire to be spoken of after one has passed out of existence; but it always stays deep in our heart. Philosophy would have us feel the vanity of it; but the feeling prevails, and this pleasure is not an illusion; for it proves to us the very real benefit of enjoying our future reputation. If our only source of good feeling were in the present, our pleasures would be even more limited than they are. (2009a: 357–58)

To be glorified is to receive praise for work or accomplishments. Considered as a passion, then, the love of glory is a love for this particular kind of praise. In the above passage, Du Châtelet acknowledges that people—in light of the previous discussion, men in particular—can enjoy some actual (non-illusory) glory in their lifetime, for instance, in receiving praise or recognition for accomplishments in war, government, or even study. For most, and especially women, she thinks, the glory one receives in life from others is limited or non-existent, as most individuals do not have the opportunity for such great accomplishments. Those who are prevented from receiving much actual glory, however, are not without hope of feeling glorified. If one’s passion is strong, one may imagine that one’s accomplishments or work will be glorified by future generations, and the feeling accompanying the thought of future recognition provides pleasure despite a lack of actual recognition.²⁵

Without the context of TPM, it is not obvious how one attains these illusions of glory. With the Malebranchean theory, we can understand how love for oneself can cause such illusions. When one considers one’s work or accomplishments, one’s love for oneself carries with it the physiological response of sending spirits to the brain, thus vivifying one’s perception of one’s accomplishments, until one imagines one’s work to be so great that it will surely be praised by posterity. The illusion is not merely itself pleasant, but also necessary for sustaining the passion for glory, which is itself a source of pleasure. The rest of the passage then makes the case that the passion of glory that illusion enables is a good thing for our happiness, because it provides us with much more pleasure than we could obtain without it.²⁶

The other example given by Du Châtelet of a passion sustained or intensified by illusion is the passion of romantic love, which she claims is where illusion is most important (2009a: 361). Here Du Châtelet’s exposition becomes personal, as she discloses her own experience in her romantic affair with Voltaire. She claims that a perfect romantic relationship is impossible; two perfectly loving souls are required, yet it would ‘exhaust the power of the deity’ to create even one (ibid.). As a result, love is imperfect and fleeting:

I do not know if love has ever brought together two people who are so made for each other that they have never known the satiety of delight, nor the cooling of passion caused by a sense of security, nor the indolence and the tedium that arise from the ease and the continuity of a relationship, and whose power of illusion never wanes (for where is illusion more important than in love?) (2009a: 360–61)

Love by necessity is unsustainable as a result of human nature, and we cannot, according to Du Châtelet, find someone so perfect for us that we do not tire of them. Though love could never be permanently sustained, Du Châtelet does argue that one who is subject to illusion can sustain the passion of love much longer than one without illusion:

And if this soul still has the good fortune to be susceptible to illusions, it is impossible that it should not believe itself more loved than it indeed may be. This soul must love so much that it loves for two, and the warmth of its heart supplies what is, in fact, lacking in its happiness. (2009a: 361/1961: 30)²⁷

When age, illness, as well as perhaps the ease of pleasure made his [Voltaire’s] inclination less, for a long time I did not perceive it; I was loving for two, I spent all my time with him, and my heart, free from suspicion, delighted in the pleasure of loving and in the illusion of believing myself loved. (2009a: 363)

The illusion Du Châtelet cites here is the belief that one is more loved than one actually is. Rather than regard this mistaken belief as a problem, she argues that such a belief can allow one to obtain more pleasure than otherwise.²⁸

Readers are likely to find this example to be somewhat implausible—after all, would not we rather just end the dying relationship than cling to something false? However, understood in the context of TPM, we should interpret Du Châtelet as believing that the passion of love always depends on illusion, not just at its end. The illusion involved in dying love, cited above, is really just a special case of the broader phenomenon of the sustaining role of illusion in loving relationships, delineated by Malebranche and Lambert. While to a twenty-first-century audience the example of illusion in dying love may seem like evidence against the illusion condition, to her contemporaries the example would appear to be an extension of TPM. This illusion and the others that sustain and intensify love make possible our loving relationships and the pleasures they bring. It thus plays an important causal role in the attainment of the pleasures that Du Châtelet believes are necessary for happiness.

Taken on their own, the two examples discussed above would offer paltry support for her illusion condition, even on the assumption that hedonism is true. The pleasures of illusory glory and unrequited love do not seem to be necessary for happiness, because one could simply fill their place with other pleasures. But in the context of TPM, these examples supplement the many other examples of the role of illusion in sustaining and intensifying the passions, allowing us to receive pleasures from them. Indeed, Du Châtelet likely includes these two examples of glory and love because of their novelty. Rather than discussing old examples, she adds to the plethora of examples already found in the tradition of TPM. Attributing TPM to Du Châtelet therefore allows us to see her remarks in the Discourse as adding to and relying on an already widely accepted theory, rather than trying to single-handedly justify the role of illusion by appealing to two otherwise puzzling examples.

Without TPM, we would need to explain the role of illusion in our happiness by appealing directly to the pleasantness of our illusions. While Du Châtelet certainly does think that illusions can themselves be pleasant, she nowhere makes the case that lacking the pleasantness of illusions would on its own make our lives necessarily unhappy. Nor should she. It is hard to imagine what illusion or set of illusions could be so pleasant that it could make us happy on its own and without which we could not reasonably expect to be happy. While it is certainly more pleasant to think highly of oneself than not, or to believe oneself loved when one is not, it should not be impossible to be happy without the pleasantness of these illusions. On my interpretation, these sorts of illusions are not necessary just because they are pleasant, but rather because they sustain the passions which themselves are the source of our greatest pleasures. If one antecedently accepts TPM (which her contemporaries did), then Du Châtelet’s illusion condition becomes much more plausible, because it supplies the causal link between illusion and the pleasures we need to be happy. As a result, I believe we are secure in attributing TPM to Du Châtelet.

A potential problem facing the passionate misrepresentation interpretation is the other important example of illusion that Du Châtelet appeals to in the Discourse: spectacles. Du Châtelet claims,

Why do I laugh more than anyone else at the puppets, if not because I allow myself to be more susceptible than anyone else to illusion, and that after a quarter of an hour I believe that it is Polichinelle, the puppet, who speaks? Would we have a moment of pleasure at the theater if we did not lend ourselves to the illusion that makes us see famous individuals that we know have been dead for a long time, speaking in Alexandrine verse? Truly, what pleasure would one have at any other spectacle where all is illusion if one was not able to abandon oneself to it? Surely there would be much to lose, and those at the opera who only have the pleasure of the music and the dances have a very meager pleasure, one well below that which this enchanting spectacle viewed as a whole provides. I have cited spectacles, because illusion is easier to perceive there. But it is mixed up with all the pleasures of our life, and it is the varnish of life. (2009a: 354/1961: 14–5)²⁹

Du Châtelet’s idea is that we enjoy spectacles because we are led into an illusion, seeing the represented events as if they are actually happening. Without the false belief that it is actually Polichenelle or Charlemagne who speaks, and not just an actor, we would see the spectacle for what it is and not for what it represents, and thus could derive no pleasure from it. The illusions about the characters of the play make possible the sort of make-believe required to immerse oneself in the story of the spectacle. While Du Châtelet claims that illusion is easy to perceive in the viewing of spectacles, she does not explicitly associate the illusions with any particular passion, as she does in the examples of glory and romantic love. Given that she seems to think spectacles provide a good example of illusions and their connection to our happiness, some will take this as evidence that Du Châtelet did not believe that TPM is necessary to understand the necessity of illusion for happiness.

This apparent problem can be addressed by recognizing that the love of spectacles (or make-believe more generally) should be regarded as a passion, in the same way that love of glory or of food are passions. It is thus possible to see how TPM could explain how illusions arise and contribute to happiness in this context. The illusions that allow us to make believe that the spectacle is real are caused by the passion for spectacles, and in turn these illusions sustain and intensify the passion, allowing us to enjoy it more and for longer. Exactly how this causal process works physiologically is not made clear by Du Châtelet or others, but it is not difficult to see how such an explanation could work. One possibility is that when one sees a spectacle and has a love for spectacles, this love vivifies their perceptions of the spectacle, in a way similar to the way that love vivifies the perceptions of the positive qualities of a friend or a lover. This vivification in turn causes the viewer of the spectacle to ignore certain facts (e.g., that the actors are on a stage, or that the puppet is in fact made of cloth) and delight in the fiction that the spectacle represents. The resulting illusions are then important for sustaining and intensifying the activity of the passion while watching the spectacle. While this explanation is not made explicit anywhere, it fits well with TPM and with the general optimism that underlying physiological mechanisms explain our mental life.³⁰ Given that TPM is at least compatible with Du Châtelet’s remarks on illusion in spectacles, and given how well TPM explains her other remarks about illusion in love and glory, the objection should not trouble my interpretation.³¹

VI. Illusions and Errors

I have argued that TPM provides a plausible explanation of why Du Châtelet thinks that illusions are necessary for happiness. I will now argue that TPM also explains her distinction between illusions and errors. Du Châtelet’s examples of illusions (of love, glory, and in the theatre) are all examples where we imagine some person or thing to be other than it truly is. These mental states would seem to be prime candidates for cognitive errors, since they lead us to believe false things about reality. If illusions are errors, then Du Châtelet faces a problem. On the one hand, she recommends that we maintain our susceptibility to illusion (e.g., 2009a: 349), but on the other hand she insists that error is always to be avoided (e.g., 2009a: 352).³² If the problem is to be solved, it must be shown that illusions, although they misrepresent, are not errors proper.

Aware of this problem, Du Châtelet claims that illusions can be distinguished from errors:

but, you will object, you have said that error is always harmful: is illusion not an error? No: illusion does not, in truth, make us see objects entirely as they are, in order to give us agreeable feelings. It adjusts them to our nature. Such are the illusions of optics;³³ but optics does not deceive us. Although it does not make us see objects as they are, this is because it makes us see them in the manner necessary for them to be useful to us. (2009a: 354/1961: 14)³⁴

Du Châtelet’s strategy likens the illusions we need for happiness to optical illusions, claiming that both are not properly errors because they merely adjust the way things appear in order for them to serve some purpose other than acquainting us with reality. The account of optics is borrowed directly from Descartes and Malebranche, who hold that although we make many errors in judgment on the basis of vision, the visual sensations themselves are not errors, despite the fact that they do not represent the world as it truly is. This is because ‘the senses were given to us, not to know the truth of things in themselves, but only for the preservation of our body’ (1980: 24). While we frequently err in our judgments about the true nature of reality on the basis of our senses, this is not the fault of our senses, but rather of our will: ‘We are deceived not by our senses but by our will, through its precipitous judgments. When, for example, we see light, it is quite certain that we see light; when we feel heat, we are not mistaken in believing that we feel heat…[but] we are mistaken in judging that the heat we feel is outside the soul that feels it’ (1980: 23). To borrow a term from Simmons (1999), we can call this the ‘bio-functional account of sensory representation’.³⁵ Although the senses do not represent the world exactly as it is, the representations of the senses are not errors. They are the necessary byproducts of the fact that our sense organs exist not to deliver the truth about the real nature of the physical world, but rather to provide information salient to our well-being; error only occurs when we make particular kinds of false judgments on the basis of these perceptions.

Du Châtelet’s comparison to sensory illusions establishes some precedent for thinking that although some mental states do not represent reality as it is, these mental states are not to be thought of as errors. The question, then, is why she thinks the illusions that are necessary for happiness should be given this same treatment. In other words, why should we think the illusions she refers to in the Discourse are bio-functional, and therefore not errors?

If we understand illusions as passionate misrepresentations, we gain a satisfying answer to this question. According to Malebranche, the passions exist to promote the good of the body: ‘We must almost always give free reign to our passions and desires in order to preserve our body and to prolong our animal existence. The senses and the passions were given to us only for the good of the body.’³⁶ Here Malebranche ascribes to the passions the same bio-functional role that he ascribes to the senses. Given that the function of the passions is not to represent reality accurately, but rather to preserve the body, its misrepresentations are not considered errors. On my view, it is this bio-functionality of the passions that distinguishes illusions from errors for Du Châtelet, in the same way that the bio-functionality of the senses distinguishes the illusions of optics from errors. Her claim is thus not a mere ad hoc claim that illusions serve our happiness and therefore are distinguishable from errors; rather, her claim is based in the theories of the passions established by Descartes and Malebranche.

Two caveats apply. First, in claiming that Du Châtelet accepts the bio-functionality of the passions and their illusions, she does not necessarily understand this bio-functionality solely in terms of the good of the body, as Malebranche clearly does. Indeed, many of the great pleasures (e.g., love and glory) that are made possible by the passions are not obviously goods related to self-preservation and flourishing of the body, but rather appear to be goods of the soul.³⁷ The reason for this discrepancy is likely the fact that Malebranche and Du Châtelet categorically disagree about the good of the soul (see section VI for more detail). For Malebranche, the good of the soul is its union with God, and thus the passions, which are directed at getting the body what it needs, can only serve to distract the soul from its ultimate good. As a hedonist, Du Châtelet thinks the only good is pleasure (2009a: 349), whether it be the soul’s or the body’s. Thus for Du Châtelet, the passions are not only bio-functional in the sense that they serve the good of the body, but they also can serve the good of the soul, since the soul’s only good is pleasure.³⁸

Second, although illusions are to be distinguished from errors, this does not mean they should be given complete free reign over our lives. Du Châtelet claims that passions are capable of making us less happy, but that this unhappiness is avoidable by exercising control over the passions through reason and reflection (2009a: 350; 357; 363–64). She insinuates we have a similar sort of control over illusion, claiming that they can be made to disappear by ‘the torch of reason’ (2009a: 349) and that it is up to us whether we choose to keep them or destroy them (2009a: 355). Marcy Lascano (2021) has argued that for Du Châtelet, the fact that we can control our illusions is another feature (along with what I have called the bio-functionality of illusion) that distinguishes illusion from certain errors, like perpetual illusions.³⁹ My aim has not been to provide an alternative to Lascano’s account, but rather only to show that by appealing to TPM, we can explain why Du Châtelet believes the passions are bio-functional, and thus distinguishable from errors.⁴⁰ This is consistent with her claim that we can (and sometimes should) control our illusions using our reason, and thus select carefully which illusions to allow in order to make our passions serve our happiness.

VII. Conclusion: Du Châtelet against the Neo-Stoics

We have seen that attributing TPM to Du Châtelet illuminates her theory of happiness with respect to two theoretical problems her account faces, namely the problem of providing an explanation of why illusions are necessary for happiness and the problem of distinguishing illusions from errors. Given the advisory tone of the Discourse, it is fitting to conclude by shifting focus from the theoretical upshot of such an interpretation to its practical upshot. The practical recommendations of her theory show how Du Châtelet’s acceptance of TPM, when combined with her hedonism, entails a rejection of the practical recommendations of Malebranche and the neo-Stoics.⁴¹ That is, by accepting their psycho-physiology and rejecting their theory of well-being, Du Châtelet shows that we ought to live in a significantly different way than the neo-Stoics suggest.⁴²

Malebranche’s theory of well-being is rooted in the fact that the human mind is capable of two unions, one with God and the other with its material body. The good of the body is its preservation, for which pleasure is a sign, while the true good of the soul comes through its union with God. The soul is torn between the pursuit of the good of the body and pursuing union with God, through which ‘the mind receives its life, its light, and its entire felicity’ (1980: xix). Malebranche blames original sin for forcing humans to neglect their true good to pursue the good of the body. ‘Most [humans] toil and struggle only to eke out a miserable existence, and to leave to their children some of the assistance necessary for the preservation of their bodies’ (1980: xxi). The small minority who obtain a position in life where they do not need to struggle to survive fare no better:

Those who, through good fortune or through their luck at birth, are not subject to this necessity, give no better evidence by their conduct that they regard their soul as the most noble part of their being. Hunting, dancing, gambling, and good living are their usual pursuits. Their soul, as the slave of the body, prizes these diversions, though they are completely unworthy of it…[C]are for their goods and desire to increase them, the passion for glory and grandeur, move them and occupy them infinitely more than the perfection of their soul. (ibid.)

The recreational activities of the privileged are viewed with disdain, as they distract the soul from God. Among their pursuits, the passion for glory is one Malebranche particularly disdains, claiming:

[The fortunate] study more to acquire a spurious grandeur in the imagination of other men than to strengthen and extend their own mind. They turn their head into a kind of furniture warehouse into which they indiscriminately cram anything bearing some mark of erudition, i.e., anything that might appear rare and extraordinary and that might excite other men’s admiration. (ibid.)

Without sounding too prejudicial, the sort of life Malebranche recommends sounds rather stoic and even monkish. The passions and the misrepresentations that sustain and intensify them are to be resisted as much as is possible (while still preserving one’s existence), in order that the soul might focus on its true good. All sorts of ordinary pleasant activities can only serve to distract us from our true and only good.

Du Châtelet’s hedonism could hardly pose a more stark contrast to Malebranche’s neo-stoicism, and this is reflected in the sort of lifestyle she recommends in the Discourse. The theory of happiness she develops directly responds to Malebranche’s accusations against the leisure class, attempting to justify the sorts of activities and lifestyle that Malebranche regards as so detrimental to the good of the soul. Recreational activities like gambling (2009a: 359), attending the theatre (2009a: 354–55), and eating fine foods (2009a: 351) she regards as worthy pursuits; glory and love are regarded not just as worthwhile but as essential to living happily. These stark differences are motivated by her rejection of Malebranche’s claim that union with God is our primary good, or even good for us at all. Rather, Du Châtelet thinks it is pleasure which is our sole good: ‘One must begin by saying to oneself, and by convincing oneself, that we have nothing to do in the world but to obtain for ourselves some agreeable sensations and feelings. The moralists who say to men, curb your passions and master your desires if you want to be happy, do not know the route to happiness’ (2009a: 349). On Du Châtelet’s view, passions and desires are the best chance to become happy through the pleasures they can bring. Though we still ought to employ reason as a guide to which passions to pursue (2009a: 364), we should not employ reason to show us how the passions we do choose to pursue deceive us, for this would undermine the very purpose of pursuing the passion in the first place.

We can now see why Du Châtelet focuses so intently throughout the Discourse on the role of illusion in happiness. In rejecting Malebranche and the neo-Stoics’ theory of value, she recommends living the hedonistic life of the passions. Yet she recognizes that recommending the passions would mean that one must allow oneself to be deceived through the illusions of the passions, as follows from TPM. Rather than attempt to amend TPM to allow for happiness without illusion, Du Châtelet simply bites the bullet and allows that certain deceptive mental states are necessary for happiness. It is her acceptance of Malebranche’s psychophysiology, and rejection of his theory of value, that leads her to claim that illusions are necessary for happiness.

Given the role illusion plays in our happiness, Du Châtelet recommends that we do what we can to preserve our illusions:

We cannot give ourselves illusions…but we can keep the illusions that we have; we can seek not to destroy them. We can choose not to go behind the set, to see the wheels that make flight, and the other machines of theatrical productions. Such is the artifice that we can use, and that artifice is neither useless nor unproductive. (2009a: 355)

As she states when discussing the passion of glory, ‘Philosophy would have us feel the vanity of it’ (2009a: 358), but this does not mean we should feel the vanity of our glory. Rather, she claims that we should not use the tools of philosophy in this case to seek the truth, dismiss illusion, and quench passion. This is the starkest difference between Du Châtelet and Malebranche. Malebranche sees these illusions as dangerous, which one should guard against by attempting to avoid various bouts of passion in the first place. Du Châtelet, on the other hand, recommends we suspend our philosophizing to allow certain passions and their illusions.⁴³ Without illusions, love would be dampened by the faults of the beloved; glory would be suppressed by doubt; friendship would never pass beyond acquaintance. To eradicate our illusions through reflection would strip the gloss from our experience and destroy our happiness. Better, then, to leave many of our passions to their natural course and enjoy the pleasures they bring.

Acknowledgements

I am thankful to Julia Jorati, Lisa Downing, and two very thoughtful anonymous reviewers for helpful comments on previous drafts, and to Loane Forest for assistance with translations. Special thanks are due to Julia Jorati, whose seminar on ethics in Early Modern Philosophy provided the impetus to explore this topic. Thanks also to audiences at the 2018 Dutch Seminar in Early Modern Philosophy (Utrecht), the 2018 Atlantic Canada Seminar in Early Modern Philosophy, and the Ohio State Early Modern Philosophy Workshop.

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