Aversion and desire work together to entrap the mind within its own projections and divide the whole into parts. The opposite of what I desire is feared and visa versa. Because the mind is a single whole, when we pit what we like against what we do not, repetitive aversive and desiring images noisily dance through the mind in opposition to the contentment of the abiding wholeness.
Metta practice makes the heart more sensitive to the joys and sorrows that sentient beings are subject to. This tenderness becomes the avenue for us to discover our deep connection to all of life and end a sense of isolation.