Biology, Social Environment, and Personalized Medicine.

These advances in the physical and biological sciences provided much needed explanations for how the body functioned in health and disease. Leading scientists such as Claude Bernard developed the concept of internal physiological balance, later named homeostasis by Walter Cannon [2, 3] . Edward Jenner introduced the method of vaccination, and Joseph Lister demonstrated the value of antisepsis [4, 5] . It was not long before those discoveries and others (e.g., Landsteiner’s system of blood compatibility, Banting and insulin for diabetes) fundamentally strengthened the benefit of treatment for individual patients. Advances in the social sciences were notable too. Progress in social theory by Comte and Spencer argued for the importance of understanding social phenomena in health and disease. Advances were also made in psychology by Dewey (educational theory), by Watson (behavioral conditioning) and by those who contributed to the rise of the cognitive sciences. Ironically none of these advances in social or behavioral science were integrated into clinical medicine or materially affected the care of the individual patient by physicians educated largely in the biological sciences. Leading scientists in the 19th century came to believe in the biological causes of disease and the “one agent, one disVariability is the law of life and as no two faces are the same, so no two bodies are alike and no two individuals react alike and behave alike under the abnormal conditions which we know as disease. Sir William Osler [1]