The biological human being is an emergent human superorganism consisting of the human organism physiologically integrated with other organisms. The persistence of a superorganism in space and time requires communication among its organisms. This communication occurs through immune processes at the biological boundaries of these organisms. Immune processes also repair disrupted boundaries, with this repair resulting in either health or disease processes depending on how the boundaries are restored. Health, disease, and biological personal identity all emerge from the mode of arrangement of, and communication of biological information among the superorganism’s parts. The study of solid organ transplantation enables the ontology of the biological human being as a superorganism by bringing together the structural and functional boundaries of different organisms in a way that communication can be better understood. By understanding that organ transplant recipients are not just non-transplanted patients with an extra part, but are newly emergent human superorganisms, we can better understand both post-transplant health and disease and target our therapies more effectively. Successful reintegration of the superorganism after disruption may be relevant to many health processes, and therefore to the goals of medicine in general