The third chapter presents the steps by which early chiropractic became an organized system of health care: the elaboration of chiropractic theories, the establishment of training institutes like the Palmer School of Chiropractic (P.S.C.) in Davenport, Iowa, and the making of a collective consciousness for the profession. Though their relationship was fraught with hostility, D. D. Palmer had considerable help from his son, B. J. Palmer, in developing chiropractic, which they had to distinguish from systems like osteopathy, with which it often was confused. Spinal therapeutics were a major part of 19th century health culture, but not originally central to chiropractic treatment or the First Chiropractic Theory. After the Santa Barbara Incident, the Palmers adopted the neurocentric logic of Progressive Era popular physiology, where maintaining the health of the nervous system through care of the spine was prioritized in the Second Chiropractic Theory.