Each of the six classes of tantra expresses this appreciative interactive empathy according to progressively subtler and increasingly vivid criteria. We begin by cultivating compassion – only to learn that compassion – is none other than the innate energy of the natural state.p133, Tracts of the Sun : An Earth Orbit of Vajrayana Expressions. Ngakpa Chögyam and Khandro Déchen, Aro Books Worldwide, 2022, ISBN 978-1-898185-28-4