Rei: Spiritual Wisdom
Mrs. Hawayo Takata, who introduced Reiki to the West, said the word Rei means universal and this is the definition most have accepted. However, Mrs. Takata also indicated that this interpretation is a very general one. The kanji ideograms have many levels of meaning. They vary from the mundane to the highly esoteric. So while it is true that Rei can be interpreted as universal, meaning that it is present everywhere, this level of interpretation really doesn't add to our understanding of Reiki.
Research into the esoteric meaning of the Japanese kanji character for Rei has given a much deeper understanding of this ideogram. The word Rei as it is used in Reiki is more accurately interpreted to mean supernatural knowledge or spiritual consciousness. This is the wisdom that comes from God or the Higher Self. This is the God-Consciousness which is all knowing. It understands each person completely. It knows the cause of all problems and difficulties and knows what to do to heal them.
Ki: The Life Force
Ki means the same as Chi in Chinese, Prana in Sanskrit and Ti or Ki in Hawaiian. It has also been called, odic force, orgone, and bioplasma. It has been given many other names by the various cultures that have been aware of it.
Ki is the life force. It is also called the vital life force or the universal life force. This is the nonphysical energy that animates all living things. As long as something is alive, it has life force circulating through it and surrounding it; when it dies, the life force departs.
If your life force is low, or if there is a restriction in its flow, you will be more vulnerable to illness. When it is high, and flowing freely, you are less likely to get sick. Life force plays an important role in everything we do. It animates the body and also is the primary energy of our emotions, thoughts and spiritual life.
The Chinese place great importance on the life force or what they call Chi. They have studied it for thousands of years and have discovered there are many different kinds of Chi. The "Yellow Emperor's Classic of Internal Medicine" which is over 4,000 years old, lists thirty-two different kinds of Chi or Ki.
Ki is used by martial artists in their physical training and mental development. It is used in meditative breathing exercises called Pranayama, and by the shamans of all cultures for divination, psychic awareness, manifestation and healing. Ki is the nonphysical energy used by all healers. Ki is present all around us and can be accumulated and guided by the mind.
Reiki: Spiritually Guided Life Force Energy
It is the God-consciousness called Rei that guides the life force called Ki in the practice we call Reiki. Therefore, Reiki can be defined as spiritually guided life force energy. This is a meaningful interpretation of the word Reiki. It more closely describes the experience most people have of it; Reiki guiding itself with its own wisdom, and being unresponsive to the direction of the practitioner.
~International Center For Reiki Training