The Heart Sutra is an act of seeing: it pares perception down until form and emptiness mirror one another and nothing stands apart. Its medicine is insight—prajñā.

The Vajrasattva Mahāmantra is an act of purification: it works not through analysis but through vibration and confession, dissolving karmic residue in the field of awareness. Its medicine is compassion and ethical clarity—karuṇā and śīla.

One clears the lens; the other clears the mirror. The first says, “There is no self, no other”; the second says, “Yet every trace of harm still matters, so let it be cleansed.”

In practice, many Vajrayāna teachers quietly pair them—Heart Sutra to stabilize view, Vajrasattva mantra to stabilize conduct. When insight and purification move together, emptiness doesn’t become nihilism and compassion doesn’t drown in guilt.

So yes, complementary: the diamond and its polish. Or in simpler language—one teaches you what’s true; the other helps you live like you know it.