a Head reversed. The seat of human consciousness, which is Solar, pertaining to Tiphereth, is in the head. Resh is the Solar letter. In shape it is merely a big Yod, implying the brain as the expansion of the Spermatozoon.
The many change and pass; the one remains. Even as wood and coal and iron burn up together in one great flame, if only that furnace be of transcendent heat; so in the alembic of this spiritual alchemy, if only the zelator blow sufficiently upon his furnace all the systems of earth are consumed in the One Knowledge.