After these two, Dr. Diet and Dr. Quiet, Dr. Merriman is requisite to preserve health.

The saying argues that health is maintained less by heroic cures than by everyday governance of life. By calling diet and quiet “doctors,” Howell elevates self-discipline and rest to the status of medicine; by adding “Dr. Merriman,” he insists that emotional tone—good spirits, sociability, laughter—also has therapeutic force. The triad implies a balanced regimen: bodily intake, bodily recovery, and mental ease. Its significance lies in how it anticipates later holistic views of health, while remaining rooted in early modern moral physiology, where passions and temperament were thought to shape the body as directly as food or sleep.