Air and Angels
Pre-incarnate love
Donne claims he loved her before meeting her—a paradox setting up the theological argument. Medieval philosophy held souls could love ideals before encountering their earthly forms.
Angelology reference
Angels were thought to appear as voices or flames because they lack bodies. Donne's using scholastic theology—angels need to 'assume' physical forms to interact with humans.
Incarnation logic
The soul takes flesh to act in the world; therefore love (the soul's 'child') must also take a body. He's applying Incarnation theology to romance.
Nautical metaphor shift
A pinnace is a small ship; 'overfraught' means overloaded. He thought her beauty would stabilize ('ballast') his love, but it's too much—the ship's sinking from excess cargo.
The turn
After 26 lines of intellectual foreplay, Donne lands his real point: women's love is to men's love as air is to angels—less pure, but necessary for incarnation. Casual misogyny dressed as metaphysics.