Voltaire on Tolerance

Quote

"What is tolerance? It is the consequence of humanity. We are all formed of frailty and error; let us pardon reciprocally each other's folly. That is the first principle of natural law."

— Voltaire, Traite sur la tolerance (Treatise on Tolerance), 1763

Historical Context

Voltaire wrote the Traite sur la tolerance in 1763, in the immediate aftermath of one of the most notorious miscarriages of justice in eighteenth-century France. On March 9, 1762, Jean Calas, a sixty-four-year-old Protestant merchant in Toulouse, was broken on the wheel and burned at the stake. His supposed crime was the murder of his eldest son, Marc-Antoine, to prevent the young man from converting to Catholicism. The evidence was nonexistent, the trial was a parody of due process, and the verdict was driven by the anti-Protestant fervor that still gripped southern France more than a century after the revocation of the Edict of Nantes. The Calas family was destroyed: the widow fled, the children were scattered, and the family's property was confiscated.

Voltaire learned of the case in 1762 and devoted the next several years to overturning the verdict. He investigated the facts, mobilized his network of correspondents across Europe, published a series of pamphlets, and eventually secured a rehearing before a special tribunal of judges. In 1765, three years after the execution, Calas was posthumously exonerated. The Traite sur la tolerance was the philosophical centerpiece of this campaign — not a legal brief but a sustained argument that the persecution of religious dissenters was both morally wrong and contrary to the deepest principles of human nature and natural law.

The treatise appeared in a France where religious toleration was a radical idea. The Edict of Nantes, which had granted limited rights to Protestants, had been revoked by Louis XIV in 1685, and Catholics who advocated tolerance were suspected of heresy. Voltaire's argument was therefore not merely a plea for one particular case but a challenge to the entire structure of state-enforced religious conformity. He drew on the history of religious persecution — from the Roman Empire's treatment of early Christians to the wars of religion and the Inquisition — to show that intolerance was not a natural human attitude but a political construction, built and maintained by those who profited from it.

It is worth noting that a different quotation — "I disapprove of what you say, but I will defend to the death your right to say it" — is frequently attributed to Voltaire but was in fact written by Evelyn Beatrice Hall in her 1906 book The Friends of Voltaire as a paraphrase of his attitude. The passage quoted here, from the Traite sur la tolerance itself, is the verified voice of Voltaire.

Philosophical Interpretation

Voltaire's definition of tolerance is deceptively simple. Tolerance, he says, is not a policy or a concession but "the consequence of humanity." The word "consequence" is precise: tolerance follows necessarily from the recognition of what human beings are. We are "formed of frailty and error" — fallible creatures who make mistakes, hold false beliefs, and act on imperfect knowledge. If this is what we are, then the demand that others conform to our beliefs, on pain of persecution, is not merely cruel but absurd. We cannot be certain that we are right and they are wrong, because certainty is not available to creatures constituted by error. The only honest response to universal fallibility is mutual pardon: "let us pardon reciprocally each other's folly."

This argument is epistemological before it is moral. Voltaire does not say that tolerance is a good thing because it produces social harmony, though he believed it did. He says tolerance is the necessary consequence of the human condition. To be human is to be fallible, and to recognize this fallibility is to recognize that no one has the standing to coerce another's conscience. This places the argument on a different footing from the prudential case for tolerance and brings it closer to a philosophical foundation for freedom of conscience. The appeal to "natural law" at the end of the passage reinforces this: tolerance is not a cultural preference but a principle that can be derived from human nature itself, accessible to reason without the need for revelation or ecclesiastical authority.

The passage also contains a subtle psychological insight. Voltaire identifies the root of intolerance not as hatred but as certainty — the conviction that one possesses the truth so completely that disagreement becomes a crime. This is why the remedy is not more knowledge but more humility. "Let us pardon reciprocally each other's folly" acknowledges that we are all, from someone else's perspective, foolish. The tolerance Voltaire advocates is not the condescension of the powerful toward the weak but the mutual recognition of shared fallibility.

It is worth noting what Voltaire's argument does not claim. He does not say that all beliefs are equally true, or that truth does not matter. Voltaire was a passionate defender of reason and a fierce critic of superstition; he did not embrace relativism. His point is narrower and more powerful: even if some beliefs are true and others false, human beings are not equipped to distinguish them with the certainty that persecution requires.

Related Concepts

The concept of tolerance that Voltaire articulates here connects to several broader philosophical traditions. In the history of ideas, the argument for religious toleration runs from Locke, whose Letter Concerning Toleration (1689) made the case on theological and political grounds, through Pierre Bayle, who argued that conscience could not be forced, to the American founders, who encoded religious freedom in the First Amendment. Voltaire's contribution is distinctive in its emphasis on fallibility as the foundation of tolerance.

The concept also resonates with the ancient virtue of humility and the Socratic recognition that the unexamined life is not worth living. Socrates claimed to know only that he did not know, and this intellectual humility was the foundation of his philosophical practice. Voltaire's "frailty and error" extends this Socratic insight from the individual to the species.

The relationship between tolerance and reason is particularly important in Voltaire's thought. Reason, for Voltaire, is not the power to achieve certainty but the discipline of recognizing one's own limitations. The fanatic is not someone who reasons too much but someone who reasons too little — who leaps from belief to certainty without passing through the intermediate stage of doubt.

Learning Path

To deepen your understanding of Voltaire's argument for tolerance, consider the following path:

1. Start with the thinker: Read the full Voltaire page to understand his biography, his deism, and his campaigns for justice beyond the Calas affair.
2. Explore the philosophical context: Voltaire's argument draws on the tradition of natural law. The political philosophy tradition, from Locke through the American and French revolutions, developed this idea into the modern framework of rights and freedoms.
3. Connect to freedom and truth: Voltaire's tolerance is grounded in the relationship between freedom and truth. If truth cannot be coerced, then freedom of conscience is not a concession but a necessity.
4. Compare with other traditions: The Greek Skeptics argued for the suspension of judgment in the face of uncertainty, and Stoicism advocated inner freedom regardless of external conditions.
5. Read the primary source: The Traite sur la tolerance is available in English translation and is one of the most accessible of Voltaire's major works.

Sources

1. Stanford Encyclopedia of Philosophy, "Voltaire." Covers the Calas affair, the Traite sur la tolerance, and Voltaire's broader campaign for religious freedom.
2. Voltaire, Treatise on Tolerance, trans. Brian Masters (Cambridge: Cambridge University Press, 2000). A modern English translation of the complete treatise with historical introduction.
3. Internet Encyclopedia of Philosophy, "Voltaire." An accessible overview of Voltaire's philosophy and activism.