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I argue that Pierre Bayle was the first modern author to re-secularize the concept of moral conscience after it had been tied to Christian theology for centuries. Bayle’s first moral writings espoused a traditional, theological conception of conscience which was unfit to support his theory of toleration. Over three decades of reflection, Bayle gradually rendered conscience completely independent of theology, and therefore made it suitable as a foundation of a theory of universal toleration. We witness in Bayle’s moral writings not only the emergence of the modern, secular conscience, but also the process of secularization.


Pierre Bayle, Conscience, Secularism, History of Ethics, Atheism, Enlightenment


The concept of moral conscience first appeared in the writings of the Greek playwrights of the fifth century BCE, at which time the concept was not tied to theology.1 According to Richard Sorabji, who has recently (2014) written the most complete and carefully documented history of the concept, conscience (suneidesis) originally referred to sharing knowledge of a defect with oneself. However, St. Paul’s historically important appropriation of the concept then gave conscience a theological turn that endured throughout the Middle Ages. In his Letter to the Romans (2:14–15), St. Paul portrays conscience as an interior witness of our actions that will either accuse or excuse us on the Day of Judgment. This concept of conscience is influential to this day,2 but since the early modern period there have been attempts to distance conscience from any theological ties. According to Sorabji, this “re-secularization” of conscience was undertaken in earnest by a number of early modern authors, especially in the eighteenth century. In recent years, other historians have been interested in the history of the modern resecularization of conscience,3 both in order to fill this proverbial gap that [End Page 199] exists in the literature on the history of ethics, and also to explore accounts of conscience that might continue to be useful today in guiding political debates surrounding freedom of conscience and conscientious objection.4

Pierre Bayle should be considered the central figure in the early modern re-secularization of conscience. Sorabji is the only recent historian of conscience to acknowledge Bayle in this history, but his focus was limited mainly to Bayle’s defenses of the rights of conscience and religious toleration. The broad scope of Sorabji’s work did not permit him to explore Bayle’s complex and evolving views on the nature of conscience itself or Bayle’s gradual development of a fully secular account of conscience. Bayle scholars have also neglected the evolution of Bayle’s conceptions of conscience,5 which is surprising given the wide interest in Bayle’s arguments for toleration, which nearly all rest on conscience. Tracing the development of Bayle’s accounts of conscience shows how Bayle developed a completely secular account of conscience by the first years of the eighteenth century, decades earlier than the other philosophers who are most often credited with this achievement, namely Butler, Rousseau, Smith, and Kant.6

Bayle’s earliest writings do not include an account of conscience that is secular; instead, they rely on a traditional, theological notion of conscience that gradually over three decades becomes a secular account of conscience as Bayle attempts to construct a theory of conscience that can support the universal toleration he wishes to defend. Bayle’s writings reveal the process of secularization—at times intentional and elegant, at other times confused and convoluted. Bayle’s writings can be viewed as a microcosm of a wider moral transformation of his period. This history is relevant to current social debates, since Bayle’s final account of conscience demonstrates how religious and non-religious accounts of conscience can be seen not as incommensurable, but rather as different interpretations of the same principle. He thereby demonstrates how religiously diverse societies can employ conscience as a common moral principle, even when there is fundamental disagreement over the definition of conscience.7 [End Page 200]


The term “secular” carries with it much contemporary moral, political, and religious baggage, so it is important, in order to avoid anachronism, to carefully define what that term, along with its cognate “secularization,” will mean here. When I claim that Bayle secularized conscience, and that his final account of conscience was completely secular, I have in mind only the six very specific and minimal elements of the secular that I identify below. That there is nothing anachronistic about the secular in this limited sense will become evident through passages from Bayle’s works which explicitly endorse these six elements of the secular conscience.8

The primary aspect of the secular is the separation of the non-religious from the religious, the natural from the supernatural.9 This fundamental aspect has guided the attempts of recent historians to track the emergence of the secular conscience in modernity. Paul Strohm equates the “secular conscience” with a conscience that can “operate without the support and arbitration of an institutional church and without a secure status as a deputy of God” and with a conscience that is free “from the supervision of this or that religious denomination.”10 For Strohm, “the secularization of conscience” therefore amounts to “the emancipation of conscience from institutional religion.”11 Similarly for Sorabji, a secular conception of conscience is one that “does not . . . necessarily refer to God.”12 Strohm and Sorabji agree that a secular account of conscience is above all an account that is independent of any particular religion or even any reference to the divine.

This negative understanding of “secular account of conscience” as primarily a non-theological account will be central to this paper. To permit a finer-grained analysis, however, I will distinguish three levels on which an account of conscience can be independent of religion: the account can be metaphysically, doxastically, or normatively secular. The account is metaphysically secular if it does not depend on any particular religion’s doctrines (including the proposition that some god exists), in order to explain the origin, the nature, or the purpose of conscience. The account is doxastically [End Page 201] secular if the account does not require that one believe some particular religion’s doctrines in order to have a properly functioning, or sound, conscience. The account is normatively secular if it does not depend on any particular religion’s doctrines in order to explain the authority that conscience should have over us, or to evaluate morally some particular conscience or conscientious action.

The secularization of conscience seems a rather arbitrary event in Western history, unless we discuss the positive goals that led authors to separate religion from morality. Charles Taylor identifies three goals of secularism in general that summarize nicely (though this was not Taylor’s goal) the positive goals that drove Bayle’s arguments for toleration, and ultimately his secularization of conscience. Taylor equates these goals with the “French Revolution trinity: liberty, equality, fraternity.”13 Adapting Taylor’s insight, I will say that a secular account of conscience is one that has three positive characteristics: it supports the freedom, the equality, and the fraternity of consciences. By “freedom of conscience” I mean both the freedom to act on one’s conscientious beliefs, and also the freedom from religious and political persecution—that is, from the attempts of religious or political authorities to command or to compel or to punish one’s conscientious beliefs or actions. By the “equality of consciences” I mean treating the nature and value of all consciences, regardless of the religious beliefs associated with them, as equal. Finally, by the “fraternity of consciences” I mean mutual respect for one another’s consciences, especially among those who disagree about important religious, political, or even moral matters.

To summarize, a negatively secular account of conscience is independent—metaphysically, doxastically, and normatively—of religious doctrine and propositions about the divine, while a positively secular account supports the freedom, equality, and fraternity of consciences. The rest of this paper will show that Bayle’s first moral writings espouse a non-secular account of conscience, while Bayle’s subsequent writings result in an account that is secular in all six ways described above. The six elements of the secular will provide a useful means of organizing the subtle developments in the account of conscience that occur across the hundreds of pages of Bayle’s moral and political writings. This organizational scheme risks giving the impression that I am arguing that Bayle was a systematic moral thinker, which could not be further from the truth. My claim is not that [End Page 202] Bayle had these six elements of the secular in mind from the outset of his career as a goal to work toward systematically. Rather, as we will see, these six secular elements are developed organically as needed by Bayle in order to achieve two related goals that he did have explicitly in mind: to provide a common principle of moral and political reasoning and to support a theory of universal toleration.


Bayle first defines “conscience” in his 1675 Ethics course (known in the literature as the Cours de morale, or simply Cours) given to his students first at the Protestant Academy in Sedan and later, with little-to-no revision,14 at the École Illustre in Rotterdam.15 Following closely upon Thomas Aquinas,16 Bayle distinguishes two aspects of conscience: a habit of the soul, synderesis, which is the “natural light by means of which we approve the principles of morality,”17 and an act of the soul, conscience (conscientia), which is “a practical judgment of the intellect telling us that something is to be done insofar as it is just [honestum], or something is to be avoided insofar as it is shameful [turpe]. It is the natural light, or in other words, the knowledge of the natural law.”18 Bayle equates both synderesis and conscience with the “natural light” (lumen naturale), which he in turn sometimes equates with the natural law, as when he describes the natural law as “a certain light shining [impressum] on the mind,”19 by means of which every person recognizes the first general principles of morality. So conscience in the Cours is the natural light, which is closely associated with, if not identical to, the natural law, which is common to and known by all people. [End Page 203]

Bayle’s account of conscience in the Cours reveals an influence not only of Aquinas, but also of the Jesuit Francisco Suárez, particularly in the case of Bayle’s near identification of conscience with the natural light and natural law. Suárez, before Bayle, considered the natural light, natural law, and conscience as nearly interchangeable: “I must add, however, that the natural light of the intellect—which is inherently to prescribe what must be done—may be called the natural law, since men retain that law in their hearts, although they may be engaged in no [specific] act of reflection or judgment.”20 Suárez adds that “in the case of the natural law, which exists in the lawgiver as none other than the eternal law, there is, in the subjects, not only an active judgment, or command, but also the [mental] illumination itself in which that law is (as it were) permanently written, and which the law is always capable of incorporating in action.”21 Conscience is also intimately tied to the natural light and natural law for Suárez: “Thus, it is easy to understand a comparison between the natural law and conscience . . . on the ground that conscience is nothing more or less than a dictate regarding what ought to be done.”22 Bayle was undoubtedly immersed in Thomistic and Jesuit moral theory during his education at the Jesuit College in Toulouse, so these influences are not surprising.

One further important element, the notion of right reason, appears in Bayle’s account of conscience in the Cours and is also difficult to distinguish from conscience because Bayle equates it with the natural law, which was in turn identified with conscience: “the natural law is this dictamen of right reason, by means of which we know that the Author of nature commands or prohibits certain things per se because they are suitable or unsuitable for a rational creature.”23 But conscience, the natural law, and right reason can be distinguished in Bayle’s Cours. Bayle defines conscience as the knowledge of the natural law; it is consequently our individual perception of what right reason dictates. The natural law and right reason shine, either brightly or dimly, in each human mind, and this illumination, or natural light, is conscience. The natural law and right reason are therefore the causes; the natural light and conscience are the effects. The natural law and right reason are absolute criteria of moral goodness; the natural light and conscience are the subjective perception of these criteria. [End Page 204]

At first glance, the conscience of the Cours seems not only traditional but also secular—there is no trace yet of theological dogma in the account. But here we must begin to distinguish levels of secularism, for the conscience of the Cours is at best doxastically secular in that the account does not require that anyone have particular beliefs about God or religion to know, by means of conscience, the most basic moral principles. However, the conscience of the Cours rests upon a theological foundation similar to those adopted by Aquinas and Suárez. Hence the account of conscience in the Cours is not metaphysically secular. Furthermore, the account is not normatively secular; it appeals to theological doctrines to establish the rules for determining the rightness and wrongness of acts of conscience. These non-secular elements are apparent in the following passage:

I say, therefore, that since some actions are called good and others bad, it is an evident proof that there is a rule [regula], and that actions done in accordance with this rule are good, while those not in conformity with this rule are bad. This rule is twofold: one which is remote, namely the eternal law, and the other which is proximate, namely human reason. The eternal law is the sovereign reason that shines in God as in the sovereign author of all things, by means of which it is just that all things be governed. Now this sovereign reason could not rule all things without ordaining that everything must tend toward an excellent end, and that beings that desire happiness must place their happiness in the possession of the highest good. . . . As for the second rule of human actions, namely right reason, it is necessary to remark that God willed that the eternal law shine in our souls, and that he imprinted on our minds the sentiment [sensum] of this rectitude which is the sovereign reason of God. We have therefore borrowed and copied, so to speak, from the eternal law certain rules to which we must conform our actions and our judgments, and these rules are what we call right reason or the natural law.24

According to this passage, God is the metaphysical origin and the telos of the rules of morality, hence of conscience itself. On a normative level, God’s nature is the origin of the rules that determine which actions are good and which actions are bad. We therefore cannot explain the nature or purpose of conscience, or determine the value of individual conscientious [End Page 205] actions without referring to God. This conceptual dependence of conscience on God is not merely theoretical. In one of only two examples of conscientious action in the Cours, Bayle demonstrates the practical import of this theological grounding. Bayle considers the case of heretics who perform actions that they falsely but conscientiously believe are permitted by God. Bayle’s assessment of such heretical acts is that they are “wrong [pravum] and contrary to right reason, despite being in conformity with this man’s conscience, since his is not in conformity with a sound conscience [non congruit conscientiae sanae].”25 This normative evaluation shows that there are limits even to the doxastic secularity of Bayle’s account of conscience in the Cours. Having true beliefs about God—i.e. being orthodox—matters when it comes to anything beyond grasping the basic principles of morality: “as for conscience, we must observe that in order for it to be a legitimate criterion [regula] of moral goodness, it must be cleared of preconceived notions and wrong opinions [pravis opinionibus].”26 The only causes of wrong opinions that Bayle identifies in the Cours are negligence and malice, which are “culpable to the highest degree.”27 So Bayle’s view seems to be that heretics are morally responsible for their errors.

Bayle’s first conception of conscience also fails to be positively secular—that is, it fails to support the freedom, equality, and fraternity of consciences. Given the culpability of heretical acts, Bayle may have considered the compulsion of heretical consciences by orthodox religious and/or political authorities to be defensible, since in the Cours Bayle identifies no reason to permit heretics to act according to their consciences. In any case, it is clear that Bayle, in endorsing the orthodox-heterodox distinction, does not support the equality of consciences in the Cours: some consciences, the conscientiae sanae, are better than others because of the religious beliefs with which they are associated. Such a view is antithetical to the fraternity of conscience. The seeds of a secular account of conscience are certainly present in the Cours, but pace Elisabeth Labrousse, the idea of God—even the correct idea of God—is far from optional in Bayle’s earliest moral theory.28 [End Page 206]


The well-known discussion of the virtuous atheist in Bayle’s Pensées diverses sur la comète (PD) is revolutionary for a variety of reasons, particularly for arguing that idolatry is worse than atheism and that a society of atheists would not be more criminal than a society of Christians. Surprisingly, however, from the point of view of the history of conscience it constitutes little more than an obvious application of the traditional natural law theory described above. As we saw, in the Cours, Bayle writes that there is not a single person who does not recognize the first general principles of morality.29 In the PD Bayle simply draws the following implication of that doctrine: “although God does not reveal himself fully to an atheist, he does not fail to act on his mind and to sustain in him that reason and intelligence by which all men understand the truth of the first principles of metaphysics and morality.”30 At most, the discussion of the virtuous atheist just reinforces the limited doxastic secularism of Bayle’s account of conscience already present in the Cours.

Nowhere in the PD does Bayle say explicitly that an atheist can have a conscience, let alone that an atheist can have a praiseworthy conscience. It is the virtuous atheist, not the conscientious atheist that Bayle describes. However, that atheists have the rudiments of conscience seems to follow plainly from what Bayle says about the atheist’s knowledge of moral first principles. So why didn’t Bayle declare in the PD that atheists can have a conscience?

Bayle was interested throughout the PD in downplaying the presence and influence of conscience in everyone, not just in atheists. The “virtue” of atheists and even of most Christians (except the few who are infused with the grace of God)31 does not spring from conscience, from principles, or from rationality. Bayle’s main moral-psychological thesis in the PD is that people do not act on the basis of their principles, so “there must be some other principle of the chastity of women and of the good qualities of men besides conscience.”32 If Bayle believed at this time that atheists could have a sound conscience, then it would not be in the interest of the argument of the PD to declare it. Instead, Bayle aimed to demonstrate that, like [End Page 207] everyone else, the atheist is moved by temperament, education, custom, and passion, and so despite his atheistic beliefs, “it is just as easy for an atheist to deprive himself of pleasure in order to help another person, as it is for an idolater to utter a false oath.”33

But it is possible that at this time Bayle did not believe that atheists could have a conscience. In a letter to Etienne Morin, Bayle claims that, like everyone else, he believed at the time of the PD that the atheist has “neither remorse of conscience nor fear of the future.”34 The editors of Bayle’s correspondence attribute this admission to Bayle’s efforts at diplomacy rather than to his sincere conviction.35 However, in a recent article, Winfried Schröder has convincingly argued that, prior to the second edition of the Dictionaire, Bayle lacked a concrete example of an atheistic system that was morally innocent, let alone morally praiseworthy.36 There were indeed atheists who lived irreproachable lives in the sense that they curbed their unruly passions and served their fellow human beings. Spinoza and Vanini are Bayle’s favorite examples. But such virtue is easily explained as an effect of temperament. Prior to 1702 (to my knowledge), Bayle never provided an example of an atheistic system that supported a notion of conscience; nor did he give an example of an atheist who clearly acted from the motive of conscience. This is perhaps why, in 1686, Bayle claimed that atheists could not be moved by conscience to teach others their atheistic beliefs.37 In any case, what is clear is that in the PD Bayle does not offer any developments toward a more secular account of conscience beyond what was already present in his Cours.


The first significant developments in Bayle’s thinking about conscience occur in his toleration writings of the period 1682–88.38 At least two causes [End Page 208] led Bayle to rethink his earlier account of conscience. First, Bayle encountered the philosophy of Malebranche, in which he found a conception of conscience that was “a particular form of ‘inner sentiment’ or ‘instinct.’ ”39 This new conception of conscience was symptomatic of a wider transformation of the concept of conscience taking place in French thought, from its narrow moral signification, to a wider morally neutral signification that English captures by means of the distinct term “consciousness.”40 The developments in Bayle’s conception of conscience in this period reveal a tension in his mind arising from this shift of meaning. Jean Le Clerc noticed the tension and observed that Bayle’s conception of conscience seemed at times to be an amalgam of the natural light and a heap of confused opinions.41 Gianluca Mori has written an erudite and detailed treatment of the sources of Bayle’s conflicting conceptions of conscience in this period.42 Recently, however, Jean-Luc Solère has called into question Mori’s thesis that there is a conflict of various conceptions of conscience in Bayle’s toleration writings, arguing that the natural law, natural light, and right reason remain the foundation of Baylean conscience from the Cours right through the Commentaire.43 Solère argues that Malebranche was not nearly as influential in the history of conscience generally, or in Bayle’s particular case, as Mori contends.

While this debate over Bayle’s sources is interesting and important, I would like to set it aside in favor of investigating in greater detail a cause of Bayle’s shifting conception of conscience that I think everybody can agree upon. As we saw, the conscience of the Cours was not a suitable foundation for a theory of toleration since it blamed heretics for their erroneous consciences rather than guaranteeing rights for these consciences. Bayle’s effort to advance a theory of universal toleration according to which each person has a reason both to refrain from persecuting those who do [End Page 209] not share their beliefs, and also to respect those people’s conscientious actions, led him to revise his earlier account of conscience. By focusing our attention on the six elements of a secular conscience laid out above, we can track this development across Bayle’s toleration writings. Secularizing conscience was not Bayle’s direct aim; offering a theory of universal toleration was the goal. The secularization of conscience was a rather inelegantly produced effect of Bayle’s various arguments for toleration.

On the face of it, the first developments in Bayle’s theory of conscience in his toleration writings led to a more theological, not a more secular account of conscience. As Mori has observed, Bayle seems to promote the “sacralization”44 or “divinization,”45 rather than the secularization, of conscience in passages like this one from the Commentaire philosophique (CP): “conscience is, with respect to each person, the voice and the law of God, known and accepted as such by each person who has a conscience, such that to violate conscience is essentially to believe that one has violated the law of God.”46 This passage (probably inspired by Aquinas)47 appears to be a clear denial of Bayle’s earlier doxastic secularism, the only secular dimension of Bayle’s first account of conscience. However, in this section I will show that this divinization is a gambit on Bayle’s part: Bayle emphasizes the divine origin of conscience in order to promote the freedom, equality, and fraternity of consciences, which are all crucial elements of his toleration project. This is a striking example of what I have been calling the “inelegance” of Bayle’s secularization of conscience: at times Bayle had to further theologize conscience in some respects in order to secularize it in other respects.

The gambit is first seen in the Critique générale (CG), where in the interest of establishing the freedom of conscience from religious and political persecution, Bayle declares that the right to legislate over conscience, that is, to establish the moral rules which conscience must obey, “is a right that belongs to God alone (for it is God alone who ought to reign over conscience).”48 The metaphysical and the normative bases of the dictates of conscience are emphatically theological in this passage, but the effect is to render conscience free from the constraints of human religious or political authorities. However, Bayle’s discussion of conscience in the CG establishes [End Page 210] only the negative freedom of conscience—the freedom from compulsion by human authorities.

Bayle first establishes the positive freedom of conscience—the freedom to act on its dictates, whatever they are—in the ninth of the Nouvelles lettres critiques (NLC), where he gives his famous analysis of the rights of truth and error, in which he argues that we are entitled to act according to our consciences, even when it is in error. The discussion is an elaboration of Bayle’s claim that God alone has authority over consciences, so the theological basis of conscience is preserved here, but again in order to increase the freedom of conscience. The way that God exercises authority over conscience is by conferring rights on the truth, namely to demand that conscience pay attention to the truth, and the right to demand that conscience act on the basis of the truth. The crucial observation that leads to the positive freedom of conscience is that no law is binding until the citizenry is notified: “if we wish to speak reasonably of the rights of truth over our soul, then it is necessary to consider the truth not in its metaphysical aspect, but as it is in the soul of each person. . . . In this respect all the rights of the truth depend on the clause, provided that it is known.”49 Having made the perception of the truth, rather than truth itself, the law over consciences, Bayle makes his final move: “I infer from the forgoing this conclusion: that in virtue of this right of the truth, error that is masked as the truth obligates us to do all the same things as the truth.”50 Heretics are now not only free, but also obligated to follow their erroneous consciences, a position diametrically opposed to Bayle’s discussion of heretics in the Cours.

However, Bayle has again emphasized a theological aspect of conscience to achieve these goals. The foundation of Bayle’s doctrine of the erring conscience is that conscience is binding because God has conferred rights upon the truth and God acknowledges a similar right of error masked as the truth to command our attention and to serve as a guide for our actions. However, this theological underpinning permits Bayle to render his account of conscience more normatively secular. Whereas in the Cours the fundamental normative criterion of actions was right reason, which Bayle described as a “copy” of the eternal law, which is God’s very nature, henceforth the fundamental normative criterion is each person’s individual perception of the truth, which is a mode of the human mind and is consequently secular. Subjective belief, not objective truth, is the rule for determining whether one’s conscientious actions are right. Beginning in 1685, [End Page 211] and to the end of his career, Bayle will consider all acts to be morally right if and only if they are done in accordance with sincerely held beliefs that have been subjected to scrutiny at some point. Bayle even flirts in 1685 with a metaphysically secular foundation of this normative criterion: “there is a general law in the universe which obliges man to submit himself to the truth as he knows it.”51 Presumably Bayle thought that this law was established by God, but the door is open to other metaphysical bases for this law, or to the consideration of this law as itself basic.

However, we may still question whether Bayle’s view of conscience is normatively secular in the NLC because of the many examples that Bayle uses to explain in detail why acts of a heretical conscience are morally innocent. Take Bayle’s example of Alcmène, the wife of Amphytrion, who sleeps with Jupiter (who has assumed Amphytrion’s demeanor perfectly), believing that Jupiter is her husband.52 Obviously Alcmène is a representation of heretics, Jupiter is the apparent truth, or false god, while Amphytrion is the objective truth, or true God. Should Amphytrion be angry with Alcmène despite her sincere mistake? Should God be angry with sincere, conscientious heretics? To answer these questions, Bayle argues that the love that Alcmène gave was, from her will’s perspective, or objectively speaking, not to Jupiter the imposter, but to Amphytrion her husband. Like Kant, Bayle is consistent in his moral writings that only the objective reality of an action, the will’s intention, matters in the normative assessment of the action;53 so Alcmène is beyond reproach. (Bayle’s use of the term “objective” is common in the period, but is different from our own. Bayle explains that two acts are “objectively the same” when “they appear to be the same from the perspective of the two wills that perform the acts.”)54 This is the case with all the heterodox: the respect they show to apparent truth is, objectively speaking, respect rendered to the absolute truth, which is God. Consequently, God will not disapprove of acts of a heretical conscience, but will be honored by them as much as he is honored by acts of an orthodox conscience. Bayle’s examples like this one widen the range of conscientious actions that should be considered morally good, and they consequently increase the freedom, equality, and fraternity of consciences. Bayle is especially keen at the conclusion of the NLC to emphasize the fraternal character of his account. He says that his doctrine of the rights of the erring conscience is necessary in order to preserve “some common principle of [End Page 212] reasoning” and to avoid “reducing the fate of religions to the law of strongest.”55 Only if we respect each other’s efforts to obey conscience can we dialogue with one another. But it is not yet clear whether his account is normatively secular. If the value of conscientious actions lies in the respect these acts render, directly or indirectly, to the true God, and if a conscience gets its moral worth by pleasing God, then the account cannot be considered normatively secular.

The CP is Bayle’s most famous work defending toleration. But it also deserves attention for the contribution that it makes to the secularization of conscience, since it is in this work that Bayle finally detaches the normative evaluation of consciences and conscientious actions from theological doctrine. Conscience, Bayle repeats at the outset of the CP,56 is the natural light of reason by means of which we perceive directly the first principles of morality. So the account is clearly doxastically secular. However, Bayle claims that everyone “perceives clearly that this light comes from God.”57 So the account is still metaphysically theological. The CP, like Bayle’s earlier toleration works, clearly promotes the freedom, equality, and fraternity of conscience.58 In what remains of this section, therefore, I will demonstrate the way in which Bayle secularizes conscience on a normative level in the CP.

In the first chapter of the CP, Bayle offers a purely secular test for determining the moral worth of some conscientious belief or some action proposed by conscience:

I would like each man who wants to perceive distinctly the natural light with respect to morality to rise above his personal interest and the customs of his country, and to ask in general: is such a thing just in itself? If it were a matter of introducing it into a country where it was never the practice, and where the people were free to take it or leave it, would those people find, upon examining it coldly, that it was just enough to deserve to be adopted by them?59

Bayle’s test evaluates the moral worth of conscientious beliefs and actions by asking whether they are universalizable. The test turns the adoption by [End Page 213] an individual of some moral belief or practice into an act of legislation over some foreign land. (The connection between this test and Kant’s categorical imperative has been noted.)60 One can simplify the argument for toleration in the CP by considering it an application of this test: if people gathered to found a new country and to decide the laws to be adopted in it, would they adopt the law that the majority religion can persecute any minority religion? Bayle’s arguments demonstrate that the answer to this question would obviously be “no.” Moreover, if people formed their consciences using this test, it is easy to see how fraternity among people of the same country and of different countries would be increased: individual moral thinking would be tantamount in every case to socially-minded thinking.

The metaphysical grounding of this test, however, is still theological: “the eternal or positive laws of God determine the distinction between crime and virtue.”61 Since God established one moral law for all people, it follows that whatever an individual takes to be morally good in general ought to be something that can be adopted by all people in all nations. Bayle’s normative test is therefore a secularized and practical version of this piece of advice: think about morality from God’s perspective—that is, universally and rationally.

However, Bayle distances the theological metaphysics of the test from the concrete normative evaluation of consciences and their acts; one need not refer to God in any way to employ Bayle’s normative test. God established the following normative criterion for judging human characters and actions: “the only law that God in his infinite wisdom could have imposed on man with respect to the truth, is to love every object that appears true to him, after having employed all his lights in the discernment of that truth.”62 Although God’s eternal law is the absolute criterion of right and wrong, one cannot expect human beings in their present condition to know that law with certainty. One can demand only that a person follow their individual conscience: “This means that conscience has been given to us as the touchstone of truth, the knowledge and love of which has been commanded of us. If you ask more of people, then it is clear that you ask for the impossible.”63

Being orthodox, having conscientious beliefs that align perfectly with the eternal law of God, is not important in normative evaluations of conscience. All that matters is that one has tried sincerely and diligently to [End Page 214] know the truth. But people can deceive themselves. What is the test to determine whether our search has been sincere and diligent? Bayle reduces the criterion of conscience to an interior sentiment: “since faith gives us no other marks of orthodoxy beyond an interior sentiment and the conviction of conscience, which are marks that find themselves in the most heretical people, it follows that the final analysis of our belief, whether orthodox or heterodox, is that we feel [sentons], and that it seems to us, that this or that is true.”64 What makes the difference between a good and bad conscience is the application of a test, a sincere and diligent search for the truth, and a peculiar sentiment that one has found the truth—all secular means. Although Bayle will not say so for over a decade, even an atheist can have a praiseworthy conscience on this account.


By 1688 Bayle’s account of conscience was secular in all respects except metaphysically. For the next decade and a half Bayle was mainly involved in two projects: fighting accusations of all sorts from Pierre Jurieu before the Walloon Consistory, and writing his masterpiece, the Dictionaire historique et critique (first edition, 1697; second edition, 1702). Although conscience is mentioned in Bayle’s writings between 1688 and 1702, the first discussion relevant to the secularization of conscience occurs in the article “Knuzen” (sic) in the second edition of the Dictionaire. In this short article Bayle finally declares explicitly that an atheist can have a conscience. He does so on the basis of the example of Matthias Knutzen, who was an atheist who anonymously distributed three texts subversive of religion around the University of Jena in 1674.65 He became the leader of a Konigsberg group known as the Conscientiaires, “because they said there was no other God, no other religion, no other legitimate magistrate besides conscience, which teaches every man the three precepts of law: do not wrong anyone, live justly, and give to each person what is owed to him.”66

Bayle declares that the example of Knutzen demonstrates “that the ideas of natural religion, the ideas of justice [honnêteté], the impressions of [End Page 215] reason, in a word, the lights of conscience, can subsist in the mind of man even after the idea of the existence of God and the faith in a life to come have been erased.”67 The article “Knuzen” is finally proof that Bayle believed that atheists can have a conscience. But the article leaves us with questions about the metaphysical foundation of conscience in a world without God. What is conscience, if it is not a light emanating from God? What grounds the criteria of right and wrong, if not the eternal law of God? In one of Bayle’s final works, he defends the metaphysics of morality from an atheist’s point of view against a variety of objections, and in so doing he fully secularizes his account of conscience.


How can the distinction between goodness and evil, rightness and wrongness, virtue and vice, be explained in the absence of a divine legislator? This is, in Bayle’s view, the strongest objection that can be raised against an atheistic system of morality:

Because [atheists] do not believe that an infinitely holy Intelligence commanded or prohibited anything, they must be persuaded that, considered in itself, no action is either good or bad, and that what we call moral goodness or moral fault depends only on the opinions of men; from which it follows that, by its nature, virtue is not preferable to vice, and we can prefer it or not indifferently in accordance with our heart’s desire.68

Bayle’s response to this objection involves demonstrating that, concerning the metaphysics of morality, atheists and most Christians offer largely the same account. Of interest is the fact that this account is fully negatively secular in that it renders the foundations of morality independent of propositions about the divine. A secular foundation of morality common to atheists and Christians is possible because the foundation of morality, Bayle argues, must be logically prior to the will of God, and so even if God exists, morality does not depend on any divine act; God’s will instead logically depends on, and is restricted by, the foundations of morality. Bayle’s argument involves siding with the “Intellectualists” against the [End Page 216] “Voluntarists” in one of early modernity’s most important theological debates, which has its roots in Western philosophy’s most enduring meta-ethical question, the Euthypro dilemma: “Is the pious being loved by the gods because it is pious, or is it pious because it is being loved by the gods?”69 Christian Intellectualists, like Aquinas, held that God commands what is good because it is good; while Christian Voluntarists, like John Duns Scotus, argue that what is commanded is good because God commands it.70

However, even if one disagrees with Bayle and the Intellectualists, one cannot deny, without condemning the thought of many giants of the Christian tradition, that Bayle has demonstrated that an atheist metaphysics of morality is possible and even plausible from a Christian perspective. Bayle does not need to show that the atheist system is the correct one; he needs only to show that it is a viable possibility. According to Bayle, the atheist might explain the metaphysics of morality in the following way:

The beauty, the order, the symmetry, the regularity, the order that we see in the universe, are the work of a Nature that lacks intelligence, and although this Nature did not follow any ideas, it nevertheless produced an infinite number of species each of which has its own essential attributes. It is not because of our opinions that fire and water have different natures, and that there is a similar difference between love and hatred or between affirmation and negation. This specific difference is founded upon the very nature of things; but how do we know it? Is it not by comparing the essential properties of one of these beings with the essential properties of the other? Now, we know in the same way that there is a specific difference between lies and the truth, loyalty and betrayal, ingratitude and gratitude, etc.; we should therefore be assured that vice and virtue differ specifically by their nature and independently of our opinions.71

The foundation of morality for an atheist is nature itself: virtue has had its specific nature and vice has had its specific nature from the beginning of the universe independent of human opinion, just as circles and valid syllogisms have had their specific natures. [End Page 217]

Bayle then cites nine authors—Turretini, DesMarets, Aquinas, Vasquez, du Hamel, Strimesius, and Molina—in order to claim that Christians have made the same claim as atheists about the brute nature of logical, mathematical, and even moral concepts: these natures have existed for all time independently of the will of God. God did not choose to bring himself into existence; he exists by the necessity of his own nature. Therefore all his attributes are necessary, including his power and his knowledge. The objects of God’s knowledge, the essences of things, must likewise be necessary:

These essences, these truths, emanate from the same necessity of nature as does the knowledge of God; since, therefore, it is by the nature of things that God exists, that he is all-powerful, and that he knows everything perfectly, it is also by the nature of things that matter, that the triangle, that man, that certain actions of men, etc., have such and such attributes essentially. God has seen from all eternity and by every necessity the essential relations of numbers, and the identity of the attribute and the subject in propositions that contain the essence of each thing. He has seen in the same manner that the term just is contained in the following: esteem what is estimable; love what is loveable; be grateful to your benefactor; fulfill the terms of a contract.72

The foundation of Christian morality can be considered theological in the sense that the distinction between virtue and vice is grounded in the nature of God. However, this foundation can also be considered non-theological or negatively secular in that the nature of God that grounds Christian morality does not itself depend on God—in the sense of depending on the divine will. God’s nature just is, not because God wills it, but rather by its very nature. At bottom this differs little, if at all, from the atheist’s metaphysics of morality, according to which Nature in general, and nature in the sense of each particular thing’s nature, just is. Moral truths, for non-voluntarist Christians and for atheists, are brute and primitive:

You have undoubtedly guessed the conclusions I wish to draw. I want to conclude that in accordance with the doctrine that Turretini and innumerable other Doctors, some Catholic and others Protestant, have adopted, and that one can uphold on the basis of [End Page 218] very strong arguments, it is necessary to agree that atheists can be persuaded that there is in virtue an intrinsic and natural beauty and justice, and in vice there is a similar intrinsic and natural deformity and injustice.73

The difference between the Christian and the atheist metaphysics of morality is consequently a matter of interpretation, rather than an unbridgeable divide. One can choose to think of morality as resting upon the nature of God, or as resting upon the nature of Nature. Either way, at a certain point, one reaches the inexplicable and intrinsic beauty of virtue and deformity of vice.

Bayle repeatedly returns to the analogy of mathematics to explain his indifference toward the foundation of ethics. Whether one thinks that the nature of a circle is grounded in God’s nature or is merely a brute fact of nature does not matter when practicing mathematics. The Christian and the atheist mathematician agree about everything that matters for the purposes of mathematics. Moral thinkers are in the same position in Bayle’s view: whether they are Christian or atheist, they agree that the natures of virtue and vice are what they are intrinsically, regardless of human opinion. Whether they have recourse to the nature of God or to brute fact in order to explain the origin of morality is unimportant: they agree about everything that matters for the purposes of morality.74

The Christian’s and the atheist’s metaphysics have been rendered alternatives, viable options among other viable options. Bayle’s metaphysics of morality is consequently neither exclusively religious nor exclusively non-religious; it is whichever you please, and so it is fully secular, since “the shift to secularity . . . consists, among other things, of a move from a society where belief in God is unchallenged and indeed, unproblematic, to one in which it is understood to be one option among others, and frequently not the easiest to embrace.”75 With this final development, Bayle fully secularized conscience and rendered it fit for continued use by subsequent Enlightenment thinkers. [End Page 219]


Labrousse thought that Bayle remained faithful throughout his life to the natural law theory presented in the Cours,76 supporting her interpretation of Bayle as a Christian philosopher. Solère has also insisted on the unchanging character of Bayle’s conceptions of conscience from the Cours through the toleration writings and beyond.77 Others have recently seen things differently, noting important shifts in Bayle’s reflection on morality and conscience. Mori and Antony McKenna have argued that Bayle moves from an initial rationalist account of conscience toward a conception of conscience as inherently religious, to a final view that the religious conscience is essentially erroneous and prone to violence, while the atheist alone can preserve morality in its purity in his conscience.78 This reading of Bayle’s moral writings supports the subversive atheistic interpretation of Bayle. Richard Popkin was influenced by this interpretation of Bayle’s moral reflection, but he resisted the atheistic spin in favor of a reading of Bayle as a skeptic with positive commitments to toleration.79 In this paper I have supported in a general way Mori’s and McKenna’s observations that there are (pace Labrousse and Solère) important shifts in Bayle’s accounts of conscience, and that Bayle shows particular interest in the morality of atheists toward the end of his career. However, like Popkin, I have resisted the view that Bayle’s philosophy leads in any way to atheism. By bringing the concept of secularism to the discussion, I have shown that Bayle’s reflections on conscience, despite complex transformations, are unified by the goals of separating the religious from the moral and political, and thereby of increasing freedom, equality, and fraternity among people. [End Page 220]

Michael W. Hickson
Trent University.


1. Richard Sorabji, Moral Conscience through the Ages: Fifth Century BCE to the Present (Oxford: Oxford University Press, 2014), 11–36.

2. See Thomas E. Hill, “Four Conceptions of Conscience,” in Integrity and Conscience, ed. Ian Shapiro and Robert Adams (New York and London: New York University Press, 1998), 13–52.

3. Douglas C. Langston, Conscience and Other Virtues: From Bonaventure to MacIntyre (University Park: The Pennsylvania State University Press, 2001); Edward Andrew, Conscience and Its Critics: Protestant Conscience, Enlightenment Reason, and Modern Subjectivity (Toronto: University of Toronto Press, 2001); Paul Strohm, Conscience: A Very Short Introduction (Oxford: Oxford University Press, 2011); C. A. Viano, La scintilla di Caino: Storia della coscienza e dei suoi usi (Torino: Bollati Boringhieri, 2013).

4. See Sorabji, Moral Conscience, 201–14; Strohm, Conscience, 76–121.

5. A notable exception to this neglect is Gianluca Mori, Bayle philosophe (Paris: Honoré champion, 1999), 273–86.

6. See Sorabji, Moral Conscience, 167–83; Strohm, Conscience, 44–49.

7. See Ryan E. Lawrence and Farr A. Curlin, “Clash of Definitions: Controversies about Conscience in Medicine,” American Journal of Bioethics 7, no. 12 (2007): 10–14.

8. Thank you to an anonymous referee for urging me to address the charge of anachronism.

9. Charles Taylor, A Secular Age (Cambridge, MA: The Belknap Press of Harvard University Press, 2007), 1–3.

10. Strohm, Conscience, 38–39.

11. Strohm, 37.

12. Sorabji, Moral Conscience, 33.

13. Taylor, “Foreword: What is Secularism?” in Secularism, Religion and Multicultural Citizenship, ed. Geoffrey Brahm and Tariq Modood (Cambridge: Cambridge University Press, 2009), xi–xxii.

14. See Elisabeth Labrousse, Pierre Bayle, tome II: Heterodoxie et rigorisme (La Haye: Martinus Nijhoff, 1964), 139–40.

15. Pierre Bayle, “Systema totius philosophiae: Brevis et accurata ethicae delineatio” [here-after cited as Cours], in Oeuvres diverses [hereafter cited as OD] 4 (La Haye, 1737), 258–67, [All translations of the Cours are my own translations of the Latin text in the OD. All translations of other texts in this paper are mine unless otherwise indicated.]

16. Thomas Aquinas, Summa Theologica, vol. 1, trans. The Fathers of the English Dominican Province (New York: Benziger Brothers, 1947), Ia.Q.79.12–13. [Hereafter cited as ST.]

17. Cours, OD 4, 260b. [The “a” and “b” in citations of the OD and other works refer to the left and right columns respectively.]

18. Cours, OD 4, 261a.

19. Cours, OD 4, 260.

20. Francisco Suárez, On Laws (De legibus), in Selections from Three Works of Francisco Suárez, S.J., vol. 2, trans. Gwladys L. Williams, Ammi Brown, and John Waldron, with revisions by Henry Davis, S.J. (New York: Oceana Publications; repr., London: Wildy and Sons, 1964), 186.

21. Suárez, On Laws, 187.

22. Suárez, 187.

23. Cours, OD 4, 262b.

24. Cours, OD 4, 261–62.

25. Cours, OD 4, 263a.

26. Cours, OD 4, 263a.

27. Cours, OD 4, 263a.

28. Labrousse, Pierre Bayle, 274.

29. Cours, OD 4, 260.

30. Bayle, Pensées diverses sur la comète [hereafter cited as PD], clxxviii, in OD 3, 114b–115a.

31. PD, clvii, OD 3, 101b.

32. PD, clxv, OD 3, 105b–106a.

33. PD, clxxvi, OD 3, 113b.

34. Letter 990, “Pierre Bayle à Etienne Morin, Rotterdam 24 Juin 1694,” in Correspondance de Pierre Bayle, vol. 9, ed. Labrousse, Antony McKenna, et al. (Oxford: Voltaire Foundation, 2012), 284.

35. See Labrousse, McKenna, et al., Correspondance de Pierre Bayle, 285n2.

36. Winfried Schröder, “L’athéisme comme défi pour les pionniers de la liberté de penser: Deux athées speculatifs dans le Dictionnaire historique et critique,” in Pierre Bayle et la liberté de conscience, ed. Philippe Fréchet (Toulouse: Anacharsis, 2012), 185–96.

37. Commentaire philosophique sur ces paroles de Jésus-Christ: Contrain-les d’entrer [hereafter cited as CP] 2, ix, in OD 2, 431a.

38. Critique générale de l’Histoire du calvinisme de M. Maimbourg (1682) [hereafter cited as CG], in OD 2, 1–160; Nouvelles lettres de l’auteur de la Critique générale de l’Histoire du calvinisme de M. Maimbourg (1685) [hereafter cited as NLC], in OD 2, 161–335; CP (1686–88), in OD 2, 355–444.

39. Mori, Bayle philosophe, 298. I would like to thank an anonymous reviewer for urging me to acknowledge the importance of Malebranche in the evolution of Bayle’s moral thought.

40. For more on this, see C. G. Davies, “Conscience” as Consciousness: The Idea of Self-Awareness in French Philosophical Writing from Descartes to Diderot (Oxford: Voltaire Foundation, 1990).

41. Jean Le Clerc, Bibliothèque universelle et historique (Amsterdam, 1687), 335. See also Mori, Bayle philosophe, 298. Thank you to an anonymous reviewer for pointing out this passage to me.

42. See Mori, Bayle philosophe, 273–320.

43. Jean-Luc Solère, “The Coherence of Bayle’s Theory of Toleration,” Journal of the History of Philosophy 54, no. 1 (2016): 39–40.

44. Mori, “Pierre Bayle, the Rights of Conscience, the ‘Remedy’ of Toleration,” Ratio Juris 10, no. 1 (1997): 45–60, at 48.

45. Mori, Bayle philosophe, 300.

46. CP 1, vi, OD 2, 384b.

47. ST, IaIIae.Q.19.5. See Mori, Bayle philosophe, 282.

48. CG, xvii, OD 2, 76b.

49. NLC, ix, OD 2, 221b.

50. NLC, ix, OD 2, 221b.

51. NLC, ix, OD 2, 222a.

52. See NLC, ix, OD 2, 229b.

53. See CP 2, ix, OD 2, 428a.

54. CP 2, ix, OD 2, 428a.

55. NLC, ix, OD 2, 227a.

56. CP 1, i, OD 2, 369a.

57. CP 1, i, OD 2, 370a.

58. For detailed discussions of these themes in the CP see John Kilcullen, Sincerity and Truth: Essays on Arnauld, Bayle, and Toleration (Oxford: Clarendon Press, 1988).

59. CP 1, i, OD 2, 368b–369a.

60. See Jean Delvolvé, Religion, critique et philosophie positive chez Pierre Bayle (New York: Burt Franklin, 1971), 419–24.

61. CP 2, ix, OD 2, 429a.

62. CP 2, x, OD 2, 437a.

63. CP 2, x, OD 2, 437b.

64. CP 2, x, OD 2, 439a.

65. Schröder, “L’athéisme comme défi,” 190.

66. Bayle, Dictionaire historique et critique [hereafter cited as DHC], vol. 2, 2nd ed. (Rotterdam: Reinier Leers, 1702), “Knuzen,” in corpore, 1724. The fifth edition is available online at

67. DHC, 2, 2nd ed., “Knuzen,” rem. A, 1724a.

68. CPD, cli, OD 3, 405b.

69. Plato, Euthyphro, 10a, in Plato: Complete Works, ed. John M. Cooper, trans. G. M. A. Grube (Indianapolis: Hackett Publishing Company, 1997), 9.

70. See J. B. Schneewind, The Invention of Autonomy: A History of Modern Moral Philosophy (New York: Cambridge University Press, 1998), 19–25.

71. CPD, cli, OD 3, 405b.

72. CPD, clii, OD 3, 409b–10a.

73. CPD, clii, OD 3, 410a.

74. See CPD, clii, OD 3, 410b.

75. Taylor, A Secular Age, 3.

76. See Labrousse, Pierre Bayle, 261.

77. Solère, “The Coherence of Bayle’s Theory of Toleration,” 39–41.

78. See Mori, Bayle philosophe, 308–309; McKenna, “From Moral Rationalism to Moral Pyrrhonism: The Paradoxical Pathway of Pierre Bayle,” in La centralità del dubbio: Un progetto di Antonio Rotondò, ed. C. Hermanin and L. Simonutti (Firenze: Olschki, 2011), 837–49.

79. Richard Popkin, The History of Scepticism: From Savonarola to Bayle (Oxford: Oxford University Press, 2003), 294–97.

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