There are truths on this side of the Pyrénées, which are falsehoods on the other.

Pascal’s remark comes from his posthumously published notes known as the Pensées, compiled after his death (1662) from fragments intended for an “apology” for Christianity. In the section often grouped under “Justice” or “Custom,” he reflects on the instability of human laws and moral judgments, which vary dramatically by place and tradition. The Pyrenees—forming a natural border between France and Spain—serve as a vivid geographic shorthand for how what one society treats as true, just, or legitimate can be rejected just across a frontier. The line is part of Pascal’s broader critique of relying on custom and political authority as foundations for truth.

The sentence crystallizes Pascal’s skepticism about purely human standards of truth and justice. He is not claiming that reality itself changes at borders, but that social “truths”—legal norms, moral verdicts, and accepted beliefs—are often contingent on local custom and power rather than grounded in universal reason. By choosing a famous boundary, he exposes how arbitrary many certainties are: what is defended as self-evident in one country may be condemned in the next. In the Pensées this supports a larger argument: if human institutions are so variable, then they cannot by themselves provide a stable foundation for ultimate truth, pushing the reader toward a higher (religious) anchor.

“Truth on this side of the Pyrenees, error on the other side.”
“Truths on this side of the Pyrenees are falsehoods on the other.”
“Truth on one side of the Pyrenees, falsehood on the other.”