(Spirit Rock Meditation Center) This talk explores the intersection of mettā practice and equanimity, in particular how the mettā training process creates and impartiality of mind that is the cornerstone of equanimity. The talk also explores the Buddha's teaching that with the cultivation of mettā no limiting action remains and how the practice naturally reveals the places where the heart is limited and the fruitfulness of investigating the energies in this so-called purification process.