"Within the Universe there are two basic principles that are reflected in all manifestations of nature and life, and these principles are called: the masculine and the feminine. All creation is a work of these two principles, which are a repetition of the two great cosmic creative principles: the Heavenly Father and the Divine Mother, of which a repetition is also the man and the woman. Everywhere in nature you will see only these two principles working together under various forms and dimensions. You will also encounter them within the human being, not only in his physical body, but even in his psychic substance where his spirit and his intellect represent the masculine principle, while his soul and his heart represent the feminine principle. These two principles must necessarily work together: separated they are sterile, unable to create, and that is why they always seek each other... Spiritual alchemy is an application of the science of the two principles within the inner life of man".
Omraam Mikhael Aivanhov