As defined by Peter Attia M.D., author of Outlive.
Medicine 1.0
The application of interventions with hypothetical benefits to those with problems who are presenting symptoms. This is Leeches and bodily humors. Medicine men. Rarely accurate, rarely helpful.
Medicine 2.0
The application of the scientific method to test hypothesized benefits of interventions for people who are already experiencing symptoms, with refinement of the practices to maximize efficacy of intervention for the sustainment of life over the next ~5-to-10 years.
Medicine 3.0
The application of the scientific method to test and refine hypothesized benefits of interventions for people who are not already sick and presenting symptoms in order to maximize their chance for a long lifespan and healthspan. Medicine 3.0 cares about how you Protect Sleep, and hone your own personal Ideal Exercise Regiment, and what you eat & drink, and your emotional health. Medicine 3.0 cares about outcomes beyond 10 years from the point of intervention.