De stichter van de osteopathie, A.T. Still (1828-1917), was geen academicus in de moderne zin van het woord. Zijn eerste, en mogelijk enige poging tot een volledige en formele definitie van osteopathie verschijnt op de laatste bladzij van zijn autobiografie:

'Osteopathy is that science which consists of such exact, exhaustive an verifiable knowledge of the strucure and function of the human mechanism, anatomical, physiological and psychological, including the chemistry and physics of it's known elements, as has made discoverable certain organic laws and remedial resources, within the body itself, by which nature under the scientific treatment peculiar to osteopathic practice, apart from all ordinary methods of extraneous, artificial or medicinal stimulation, and in harmonious accord with it's own mechanical principles, molecular activities, and metabolic processes, may recover from displacements, disorganisations, derangements and consequent disease, and regain it's normal equilibrium of form and function in health and strength' (eerste editie 1908) (deze authentieke definitie is met opzet in de oorspronkelijke taal en onbewerkt gelaten om de kracht en zuiverheid ongemoeid te laten (noot vertaler)).