The ancient yogis believed that there was an actual center of spiritual
consciousness, called "the lotus of the heart," situated between the
abdomen and the throax, which could be revealed in deep meditation.
They claimed that it had the form of a lotus and that it shone with
an inner light. It was said to be "beyond sorrow," since those
who saw it were filled with an extraordinary sense of peace and joy.
(p. 49)