‘To practice medicine with a safe conscience’

Chapter 18, ‘To practice medicine with a safe conscience: rational therapeutics’ summarizes both parts of Pharmaceutice rationalis (1674, 1675), The London practice of physick (1685), A plain and easie method for preserving those that are well from the infection of the plague (1691) and Dr Willis’s receipts for the cure of all distempers (1701). The analysis emphasizes that the theme running through these treatises is Willis’s concept that vitality is dependent on healthy nutrition, adequate respiration, fermentation and circulation of the blood, and excretion. His therapies target one or other of these processes, usually in combination. The point is made that although most of the ingredients are no longer favoured, Willis’s pharmacopoeia is rational in the context of his ideas. His advice on lifestyle with botanical remedies and the products of chemical laboratories are described. In addition to surgical manoeuvres such as bleeding and the cutting of issues and fontanels, details are provided of innovative procedures including oesophageal stenting and drainage of pleural fluid. {150 words}