The heart, like the stomach, wants a varied diet.

Flaubert’s aphorism treats emotional life as bodily appetite: just as the stomach tires of monotony and seeks different foods, the “heart” (desire, affection, curiosity) craves novelty and variety. The comparison can be read as a coolly realistic—or even cynical—comment on romantic fidelity, suggesting that constancy is not the heart’s default condition. It also gestures toward a broader psychological truth: people often need changing experiences, relationships, or forms of attention to feel alive. The line’s force comes from its plain, almost clinical metaphor, reducing lofty sentiment to physiology and implying that love is subject to the same restless consumption as hunger.