The third magisterium was accessible only to a very few alchemists. Just as the molecules of metals are transformed under great increase of temperature, so the emotional elements in human nature undergo an increased intensity of vibrations, which transforms them and makes them spiritual. In its third and final stage, the secret of the Philosopher's Stone enabled a man's soul to attain unity with the divine spirit. The laws of Nature are alike for that which is Above and for that which is Below. Nature changes according to an ideal.
Gold is the perfection of terrestrial substances, and it is to produce gold that minerals evolve.
The human body is the model of the animal kingdom, and living forms orientate themselves in the direction of their ideal type. The emotional substance of the soul strives, through the filter of the senses, to transform itself into spirit and return to unity with the divine. The movements of Nature are governed by this single law, which is diverse in its manifestations but uniform in its essence.