The heart has its reasons of which reason knows nothing.

Pascal’s line comes from his posthumously published notes known as the Pensées, compiled after his death (1662) from fragments intended for an “apology” defending Christianity. Writing amid the intellectual climate of 17th‑century France—marked by the rise of mathematical method, Cartesian rationalism, and religious controversy—Pascal (a mathematician and Jansenist sympathizer) repeatedly contrasts the limits of discursive reason with other modes of knowing. In the Pensées he argues that certain fundamental commitments (especially in religion) are not reached by proof alone but by an intuitive, affective faculty he calls “the heart.”

The aphorism asserts that human beings possess a kind of insight—rooted in intuition, feeling, and lived experience—that cannot be reduced to formal logic. “Heart” here is not mere sentimentality; it names a faculty that apprehends first principles and personal truths (trust, love, faith, moral perception) that elude demonstration. Pascal’s point is both epistemological and existential: rational argument has real power, but it cannot fully account for why we commit ourselves, what we value, or how we recognize meaning. The line has endured because it captures the tension between analytic explanation and the irreducibly human grounds of conviction.

French original commonly cited: « Le cœur a ses raisons que la raison ne connaît point. »