Chapter IX: Theory and Observation, 200

All real knowledge based upon observation, not on theory. Facts
of two kinds—individual and general. General facts ascertained
by observation of many individual or particular facts. No theory
founded on facts—always goes beyond them. No science in which there
has been so much theorizing as in medicine. History of medicine
very much a history of theories. Office of theory—_suggestive_.
Abuse of theory in failing to distinguish between the known and the
supposed. Newton’s carefulness on this point. Circumstances impairing
skill in observation. Mode of reviewing cases. Disposition to form
conclusions from a limited range of facts. Young practitioners.
Dr. Sewall’s plates. Dr. Sutton’s treatment of delirium tremens.
Different theories of fever—Boerhaave, Cullen, Clutterbuck,
Broussais, Cooke, Samuel Thompson. Hobby-riding. Diseases of
the throat and windpipe. Habit of making loose and exaggerated
statements. Credulity and fondness for novelty and change. Changeable
state of medicine. No standard _authorities_ as in law and theology.
Scepticism in medicine. _Easy to theorize—difficult to observe well._
Value of good habits of observation. Medical men had too much to do
with theories and modes and systems. Eclecticism. _Modus operandi_
of medicines. A reform in progress in medicine. Breaking loose from
theory. Promoting rigid observation.