[Skull]

More from "What is Truth?" article:

On the plane of spirituality,
to reach the Sun of Truth we must work in dead earnest for the
development of our higher nature. We know that by paralyzing gradually
within ourselves the appetites of the lower personality, and thereby
deadening the voice of the purely physiological mind—that mind which
depends upon, and is inseparable from, its medium or vehicle, the
organic brain—the animal man in us may make room for the spiritual;
and once aroused from its latent state, the highest spiritual senses and
perceptions grow in us in proportion, and develop pari passu with the
“divine man.” This is what the great adepts, the Yogis in the East and the
Mystics in the West, have always done and are still doing.