Herbs are Earth magic. They allow you to "step aside" and let them in to heal you.
Earth, correlates with the lower dantian or jiao. It is the center of the reproductive system or creative center of your universe (your body). The kidneys are the foundation of the human body, located in the lower jiao, thus are the gateway of life.
Herbs, being of the earth, harmonize with your heart and regulate your spirit in a natural process of Kan and Li (the flow of energy between the heart and kidneys or fire and water elements).
Meditation upon herbs and practical experience with the use of different medicines have given us thousands of amazing remedies for just about any malady.
Herbs are meant to either open or close "doorways" within and around your body. Physical sites, as cell receptors, or energetic pathways in your aura. The changing of these doors will either "tonify" (build-up) or "reduce" (break-down) a body pattern.
When either your spiritual or physical body is too exhausted to transform negative traumas or emotions into healing, herbal medicines are the foundation of any treatment.