When the heart speaks, the mind finds it indecent to object.

The line contrasts two inner authorities: the “heart” as the seat of desire, intuition, or emotional certainty, and the “mind” as the faculty of critique and rational objection. Kundera suggests that once feeling asserts itself with conviction, reason often experiences resistance as socially or morally “indecent”—as if questioning emotion were a breach of decorum. The phrasing implies not that reason is disproved, but that it is shamed into silence, revealing how people rationalize choices already made by passion. In Kundera’s fiction, such tensions frequently expose the fragility of self-knowledge and the ways sentiment can commandeer intellectual integrity.