Heart Virtues are pure emotional states of Universal Love. They are so-called WingMakers Tools - they are "Tools for creating new ways of perceiving reality".
For additional reading on the Six Heart Virtues, there are free papers written by James Mahu available on WingMakers.com:
The Sovereign Integral paper is available on another James Mahu website:
Life Principles of the Sovereign Integral is Chamber 1 Philosophy on WingMakers website: