The soul sometimes experiences life through the heart of another. In the case of a living person it is only done when he is master of harmony and concentration. But a spirit that has left its body on earth and passed away to the other side becomes master, for it has one vehicle less of the many vehicles that keep the spirit captive.

The secret of experiencing through another person's heart is to focus one's own heart on the heart of the other. This is easily done by love, and sometimes by concentration [alone], but concentration and love combined give mastery over it. The heart is pictured by the mystics as a mirror, and as the reflections of one mirror can be reflected in another mirror, so it is with hearts.

The heart which perceives reflection from the other heart should be without any reflections in it, by which is meant it should be pure from any other thought or feeling at the time.
But the heart which throws the reflection has a much more difficult part to play. It has to force its own reflection through a heart which may perhaps be full of reflections. Therefore reading the thoughts of another, or knowing the feeling of another, is not so difficult as sending a thought to another or expressing one's feeling to another. It requires strength of will, good concentration, and the right way of directing the reflection, with fineness or purity of thought and feeling.