Baron d’Holbach’s Essay on Prejudices, or The Influence of Opinions on Morals and Happiness stands as one of the most uncompromising works of Enlightenment philosophy, a systematic demolition of the intellectual foundations of ancien régime society. Published anonymously in 1770 in Amsterdam, this treatise represents d’Holbach at his most radical, attacking not merely specific institutions but the very mechanism by which authority perpetuates itself: the cultivation and exploitation of prejudice. The work argues that human misery stems primarily from false opinions instilled by those who benefit from keeping populations ignorant, superstitious, and divided. D’Holbach contends that prejudices—by which he means unfounded beliefs accepted without examination—corrupt morals, poison social relations, and prevent human happiness. Only by exposing these prejudices to rational scrutiny and replacing them with opinions grounded in nature, reason, and utility can humanity achieve genuine well-being.
The Nature and Origins of Prejudice
D’Holbach opens by defining prejudice as opinion adopted without examination, belief accepted on authority rather than reason. Prejudices are errors of judgment that become habitual, transmitted from generation to generation, embedded in education, reinforced by custom, and protected by those who profit from them. He distinguishes prejudice sharply from legitimate opinion formed through rational inquiry and experience. The prejudiced person accepts claims because they come from tradition, authority figures, or popular consensus, never subjecting them to critical scrutiny.
The work traces prejudices to several sources. The first is childhood education, when the mind is most impressionable and least capable of critical judgment. Children absorb the opinions of parents, teachers, and nurses without question, forming mental habits that persist into adulthood. Religious instruction particularly exploits this vulnerability, implanting supernatural fears and dogmas before reason can develop. The second source is authority—political, religious, and social institutions that claim the right to dictate belief. Priests, monarchs, and aristocrats all benefit from populations that accept their pronouncements uncritically. The third source is custom and habit: what has always been done acquires the force of natural law in unreflective minds. Finally, prejudice arises from ignorance itself—the absence of genuine knowledge creates a vacuum filled by superstition, rumor, and convenient falsehood.
D’Holbach emphasizes that prejudices are not random errors but serve specific interests. Those who hold power—whether political, religious, or economic—actively cultivate prejudices that legitimize their authority and prevent challenges to their position. The priest benefits from supernatural terrors that make populations dependent on his mediation with the divine. The monarch benefits from doctrines of divine right and passive obedience that render subjects compliant. The aristocrat benefits from prejudices about blood, honor, and natural hierarchy that justify inherited privilege. Prejudice is thus a tool of domination, and its persistence reflects not human stupidity but systematic indoctrination by the powerful.
Religious Prejudice as the Foundation of Error
The bulk of d’Holbach’s analysis focuses on religious prejudice, which he considers the most pernicious and the foundation of most other errors. Religious belief, he argues, rests entirely on prejudice—on claims accepted without evidence, indeed claims that contradict both reason and experience. The existence of God, the immortality of the soul, divine providence, revelation, miracles: all are assertions that cannot withstand rational examination yet are imposed on children before they can think critically and maintained through fear, habit, and social pressure.
D’Holbach systematically dismantles the intellectual foundations of religion. The concept of God, he argues, is incoherent—an infinite being is beyond human comprehension, yet religions claim detailed knowledge of divine attributes, desires, and commands. The problem of evil demonstrates that an omnipotent, benevolent deity is incompatible with observable reality. Miracles violate the regularity of nature that makes knowledge possible. Revelation claims are contradictory across religions and lack credible evidence. The soul is an unnecessary hypothesis—mental phenomena can be explained as functions of material organization. Immortality is wishful thinking unsupported by observation of nature’s processes.
But d’Holbach’s critique goes beyond demonstrating religion’s falsity to exposing its harmful consequences. Religious prejudice corrupts morality by substituting arbitrary divine commands for natural ethics based on human welfare. It makes virtue consist in ritual observance, belief in dogma, and obedience to priests rather than in actions that benefit humanity. It creates artificial crimes—heresy, blasphemy, apostasy—that harm no one yet are punished more severely than genuine offenses. It divides humanity into hostile factions, each convinced of its exclusive possession of truth and willing to persecute others. Religious wars, inquisitions, and persecutions all flow from the prejudice that one’s own religious opinions are sacred truths that must be imposed on others.
Religious prejudice also prevents human happiness by filling minds with terrors and false hopes. The believer lives in fear of divine punishment, worried about offending an invisible tyrant whose will is unknowable and whose justice is arbitrary. He wastes life preparing for an imaginary afterlife rather than pursuing real happiness in the present. He accepts earthly suffering as divinely ordained rather than working to improve conditions. He submits to priestly authority, political tyranny, and social injustice because religion teaches that the existing order reflects divine will and that resistance is sinful.
D’Holbach reserves particular scorn for the clergy, whom he portrays as conscious deceivers who exploit religious prejudice for their own benefit. Priests, he argues, know that their doctrines are false but perpetuate them because religion is their livelihood and source of power. They deliberately keep populations ignorant, opposing education and free inquiry that might expose religious claims to scrutiny. They ally with political authorities, offering ideological support for tyranny in exchange for protection and privilege. They cultivate superstition, multiply mysteries, and complicate doctrine to make themselves indispensable as interpreters of divine will.
Political Prejudice and Tyranny
From religious prejudice, d’Holbach turns to political prejudice—the false opinions that legitimize despotism and prevent good government. The most fundamental political prejudice is that monarchs rule by divine right, that their authority comes from God rather than from the consent and interest of the governed. This prejudice makes political power arbitrary and absolute, placing rulers above law and accountability. It teaches subjects that obedience is a religious duty, that resistance to tyranny is sinful, and that suffering under bad government must be endured as divine punishment for collective sin.
D’Holbach argues that legitimate government rests on a social contract: individuals form political societies for mutual benefit and delegate authority to rulers for the purpose of securing general welfare. Government is a human institution, justified only by its utility, and rulers are servants of the public good, not masters. When government fails to serve the common interest—when it becomes tyrannical, oppressive, or corrupt—the people have the right to reform or replace it. The prejudice of divine right inverts this relationship, making the people exist for the ruler rather than the ruler for the people.
Other political prejudices support tyranny. The prejudice of passive obedience teaches that subjects must submit to any command, however unjust. The prejudice of hereditary privilege treats political authority as property to be inherited rather than as a trust to be earned. The prejudice of national glory justifies wars of conquest that benefit rulers while devastating populations. The prejudice of raison d’état excuses any crime committed by government in the name of state interest. All these prejudices serve the powerful by preventing rational evaluation of government performance and blocking reform.
D’Holbach connects political prejudice to religious prejudice: the alliance of throne and altar is mutually reinforcing. Religion teaches that political authority is sacred, that kings are God’s representatives, and that obedience to rulers is obedience to God. In return, political power protects religious institutions, enforces religious conformity, and punishes those who question religious authority. This alliance keeps populations doubly enslaved—to both spiritual and temporal tyranny—and makes reform doubly difficult, since challenging either religious or political authority appears to threaten both.
The work also addresses prejudices about social hierarchy and aristocratic privilege. The notion that noble birth confers superior virtue, that aristocrats are naturally fitted to rule, that inherited rank deserves deference—all are prejudices that serve the interests of a parasitic class. D’Holbach argues that virtue and talent are distributed without regard to birth, that hereditary aristocracy produces incompetent rulers and unjust social arrangements, and that rational society would reward merit rather than ancestry.
Moral Prejudice and the Corruption of Ethics
D’Holbach examines how prejudice corrupts moral understanding, substituting arbitrary rules for natural ethics. True morality, he argues, is based on human nature and social utility: actions are good when they promote human welfare and happiness, bad when they cause suffering and harm. This natural morality is accessible to reason and consistent across cultures. But prejudice—especially religious prejudice—obscures natural morality with supernatural commands, ritual requirements, and arbitrary prohibitions.
Religious morality makes virtue consist in belief, worship, and obedience to priests rather than in beneficial action. It creates victimless crimes—heresy, blasphemy, sexual nonconformity—that harm no one but offend religious sensibility. It treats natural desires as sinful, producing guilt, repression, and psychological torment. It values faith over reason, humility over self-respect, otherworldly hopes over earthly improvement. It preaches forgiveness and submission rather than justice and resistance to oppression.
D’Holbach argues that religious morality actually undermines genuine virtue. By making salvation depend on belief and ritual rather than conduct, it allows believers to commit real crimes while maintaining religious observance. By teaching that earthly life is merely preparation for eternity, it devalues human welfare and justifies indifference to suffering. By dividing humanity into believers and infidels, it restricts moral concern to one’s own religious community and permits or even mandates cruelty toward outsiders. Religious wars, inquisitions, and persecutions demonstrate that religious morality can motivate the worst atrocities.
The work also addresses prejudices about honor, reputation, and social propriety that govern aristocratic society. These prejudices make virtue consist in maintaining appearances, following arbitrary codes of conduct, and defending one’s reputation through dueling and vengeance rather than in genuine moral worth. They value pride, vanity, and sensitivity to insult over humility, honesty, and concern for others. They create artificial standards of behavior that vary by class and serve to distinguish aristocrats from commoners rather than to promote general welfare.
D’Holbach contrasts these corrupt moral systems with natural morality based on reason and utility. Natural morality recognizes that humans are social beings whose happiness depends on cooperation and mutual aid. It identifies virtue with actions that benefit society and vice with actions that harm it. It grounds moral rules in observable consequences rather than supernatural commands or arbitrary customs. It is universal, accessible to all through reason and experience, and consistent with human nature rather than opposed to it.
The Influence of Prejudice on Happiness
A central theme of the work is that prejudice is the primary obstacle to human happiness. D’Holbach argues that humans are naturally capable of happiness—that nature provides the means for satisfying our needs and that reason can guide us to well-being. But prejudice prevents us from achieving happiness by filling our minds with false fears, directing our efforts toward imaginary goods, and supporting institutions that create unnecessary suffering.
Religious prejudice makes people miserable by teaching them to fear divine punishment, to feel guilty about natural desires, to waste life in ritual observance and preparation for an imaginary afterlife, and to accept earthly suffering as divinely ordained. The believer lives in constant anxiety about offending God, worried about the state of his soul, terrified of eternal damnation. He denies himself legitimate pleasures, viewing them as sinful. He submits to priestly authority and accepts religious impositions that restrict his freedom and consume his resources. He fails to pursue real happiness because religion teaches that earthly life is unimportant compared to eternity.
Political prejudice makes people miserable by legitimizing tyranny and preventing good government. When populations believe that rulers have divine authority and that obedience is a religious duty, they submit to oppression, exploitation, and injustice rather than demanding accountable government that serves their interests. They accept poverty, inequality, and arbitrary power as natural or divinely ordained rather than as remediable evils. They fight wars for their rulers’ glory rather than their own welfare. They remain ignorant and powerless because education and political participation are restricted to preserve elite privilege.
Social prejudices about rank, honor, and propriety create artificial needs and anxieties that prevent contentment. The aristocrat must maintain expensive displays to preserve status, engage in duels to defend honor, and conform to elaborate codes of conduct that restrict freedom. The commoner must defer to superiors, accept inferior status, and abandon aspirations for improvement. Both are trapped in systems of artificial distinction that create envy, resentment, and unhappiness while serving no genuine human need.
D’Holbach argues that eliminating prejudice would dramatically improve human welfare. Without religious terrors, people could pursue happiness in this life without guilt or fear. Without political prejudices supporting tyranny, governments could be reformed to serve the common good. Without social prejudices about rank and honor, people could relate as equals and cooperate for mutual benefit. Reason and natural morality could guide human affairs, producing just institutions, rational policies, and genuine human flourishing.
The Path to Enlightenment
The final sections of the work address how prejudice can be overcome and reason established. D’Holbach acknowledges that eliminating prejudice is difficult because it is deeply rooted in education, reinforced by powerful institutions, and protected by those who benefit from it. But he insists that progress is possible through education, free inquiry, and the spread of philosophy.
Education must be reformed to cultivate reason rather than implant prejudice. Children should be taught to think critically, to demand evidence for claims, to question authority, and to base opinions on observation and logic rather than tradition. They should learn natural science, which demonstrates the regularity of nature and undermines supernatural beliefs. They should study history, which reveals the human origins of institutions presented as divine. They should be exposed to diverse opinions and taught to evaluate them rationally rather than accepting one set of beliefs uncritically.
Free inquiry must be protected and encouraged. Censorship, which prevents examination of received opinions, must be abolished. Philosophers must be free to publish critiques of religion, government, and social arrangements without fear of persecution. Public debate must be permitted so that false opinions can be exposed and refuted. The circulation of books and ideas must be unrestricted so that enlightenment can spread.
D’Holbach places particular emphasis on the role of philosophers and intellectuals in combating prejudice. They must expose the falsity of religious claims, the injustice of political tyranny, and the arbitrariness of social hierarchies. They must articulate natural morality based on reason and utility. They must demonstrate that human welfare depends on rational institutions, not supernatural intervention. They must show that happiness is achievable in this life through reason, virtue, and just social arrangements.
The work acknowledges that those who benefit from prejudice—priests, monarchs, aristocrats—will resist enlightenment and may persecute those who spread it. But d’Holbach expresses confidence that truth will ultimately prevail because it accords with human nature and serves human interests, while prejudice requires constant effort to maintain and ultimately fails to satisfy human needs. As education spreads and more people learn to think critically, prejudice will gradually lose its hold, and rational institutions will replace those based on superstition and force.
D’Holbach envisions a future society based on reason rather than prejudice. In such a society, religion would be replaced by natural morality and scientific understanding. Government would be accountable to the governed and directed toward public welfare. Social distinctions would be based on merit rather than birth. Education would cultivate reason and virtue. People would be free to pursue happiness without supernatural terrors or political oppression. Human welfare would improve dramatically as rational policies replaced those based on prejudice and superstition.
Context and Significance
The Essay on Prejudices represents the culmination of d’Holbach’s philosophical project and stands as one of the most radical works of the French Enlightenment. Paul-Henri Thiry, Baron d’Holbach was a German-born French philosopher, encyclopedist, and salon host who became the center of the radical wing of the Enlightenment. His Paris salon brought together the most advanced thinkers of the age, and he used his wealth to support philosophical publication and the dissemination of materialist and atheist ideas.
The work builds on d’Holbach’s earlier philosophical writings, particularly his systematic materialism and atheism. It applies his naturalistic worldview to social and political questions, arguing that just as supernatural explanations are unnecessary in natural philosophy, so supernatural authority is unnecessary and harmful in morals and politics. The work shares themes with his other major treatises—the critique of religion, the emphasis on utility as the basis of morality, the confidence in reason’s ability to improve human affairs—but focuses specifically on the mechanism by which false opinions are created and maintained.
The Essay on Prejudices was published anonymously, like most of d’Holbach’s works, because its radical content made open publication dangerous. The work’s atheism, its attack on monarchy and aristocracy, and its call for fundamental social transformation would have resulted in prosecution had the author been identified. Even anonymous publication in Amsterdam, outside French jurisdiction, did not fully protect the work—it was condemned by authorities and copies were seized and burned.
The work’s influence was significant within radical Enlightenment circles. It provided a systematic analysis of how authority maintains itself through the cultivation of prejudice and offered a program for social transformation through education and the spread of reason. Its uncompromising atheism and materialism went beyond what most Enlightenment thinkers were willing to embrace publicly, but it influenced more cautious reformers and contributed to the intellectual ferment that preceded the French Revolution.
The Essay on Prejudices exemplifies the radical Enlightenment’s faith in reason’s power to transform society. D’Holbach believed that human misery was not inevitable but resulted from false opinions that could be corrected through education and free inquiry. He was confident that exposing prejudice to rational scrutiny would lead to its collapse and that rational institutions would produce human happiness. This optimism about reason’s transformative power, combined with uncompromising critique of existing institutions, made the work both inspiring to radicals and threatening to authorities.
The work remains significant as a systematic analysis of how ideology functions to maintain power and as an articulation of the Enlightenment project in its most radical form. D’Holbach’s argument that prejudice serves the interests of the powerful, that it is transmitted through education and protected by institutions, and that it can be overcome through critical reason anticipates later analyses of ideology and false consciousness. His vision of a rational society based on natural morality and accountable government influenced revolutionary thought and continues to resonate in debates about the relationship between reason, authority, and human welfare.
