Ay, springes to catch woodcocks. I do know, / When the blood burns, how prodigal the soul / Lends the tongue vows: these blazes, daughter, / Giving more light than heat, extinct in both, / Even in their promise, as it is a-making, / You must not take for fire.
Act I, Scene 3 · Polonius
Context
Polonius dismisses Hamlet's vows of love to Ophelia as traps and empty words. He explains that passionate promises made in the heat of desire are unreliable and will not last.
Analysis
The image 'these blazes...giving more light than heat, extinct in both' captures the exact moment of collapse—the fire looks impressive but provides neither illumination nor warmth, dying even as it flares. This paradox (appearing to give light but actually giving none) perfectly mirrors the play's central theme of appearance versus reality, and Polonius's own speech: he sounds authoritative but offers no real insight, only clichés and metaphors that sound wise but mean little.
Essay Tip
Support a thesis that Polonius projects his own hollowness onto Hamlet—his metaphor of empty blazes describes his own language more than Hamlet's love, which creates dramatic irony and positions him as unable to recognize genuine feeling because he himself only performs wisdom rather than embodying it.