"Above-down, inside-out" is a poetic coinage by Dr. B.J. Palmer, one of the founders of the field of chiropractic. "B.J.", as he has been affectionately known by chiropractors for almost 100 years, was describing the inner workings of the brain and spinal cord, the complex nerve system connected to all parts of the body, and the cells, tissues, and organs comprising the bulk of human physiology.
In his inimitable style, Dr. Palmer was addressing many deep, complex phenomena all at once. From a high-level viewpoint, he was describing how the central nervous system communicates with the rest of the body. One major conclusion is that the brain (as the originator of nerve signals that flow to the spinal cord and from there to the organs, tissues, and cells) is the master controller of all the other systems. The gastrointestinal, endocrine, cardiopulmonary, and musculoskeletal systems are all ultimately controlled and regulated by activities within the brain.
More than this, "B.J." was pointing directly to an organizing intelligence responsible for all the operations of living tissue. This concept, "Innate Intelligence", was propounded by his father, Dr. Daniel David Palmer. "B.J." expanded, publicized, and promoted the idea of Innate Intelligence as he helped the field of chiropractic grow into the second largest healing arts profession in the United States.
In the above-down, inside-out paradigm, Innate Intelligence is an intrinsic guiding and instructional force that maintained ongoing health and healing. Innate Intelligence knows how much oxygen and other nutrients a cell needs to meet its energy requirements. Innate Intelligence knows how to direct B lymphocytes to build a new antibody to fight a previously unencountered bacteria or virus. Innate Intelligence knows how much insulin should be released by beta cells in the pancreatic islets of Langerhans in order to properly use the carbohydrates you ingested during your last heart-healthy meal.
But disorder within the nerve system can interfere with the body's ability to carry out the instructions of Innate Intelligence. Symptoms, pain, disorders, and disease ensue from such nerve interference. Chiropractic care helps restore balance within the nerve system, thus helping restore health and well-being.