Book III, 65: On Doves and Serpents

We must have Doves and Serpents in our heart,
But how they must be marshall'd there's the Art;
They must agree, and not be farre asunder;
The Dove must hold the wily Serpent under:
Their natures teach what places they must keepe,
The Dove can flye, the Serpent onely creepe.