Reprinted from American Journal of Psychiatry 1969 125 1131-2

NATHAN S KLINE, MD

Dr Blackwell's delightful letter reads as though it were written by one of Cinderella's spiteful sisters. Lithium is more like the lost slipper than the pumpkin-stagecoach. It isn't meant for everyone, but when it does fit, there actually is a fairy story quality about it.

In view of the lack of "proper controlled evaluation of therapy" in all area of medicine prior to 20 or 30 years ago, it is really most disconcerting to note the discovery of quinine, digitalis, opiates, aspirin, and a few hundred other useful pharmaceuticals. There is even a feeling of faint personal familiarity with Dr Blackwell's "warning" which reminds me of some of the caveats concerning the introduction of both the antipsychotic and antidepressant agents. Of course it may also be that Dr Blackwell is also not convinced that any of these drugs have been demonstrated to be of use.

The real problem would seem to be the relatively medieval mathematical model upon which Dr Blackwell is "hung-up". Its application in most cases constitutes a triumph of technique over purpose. Fortunately it now appears that most of us (like the hero of "Le Bourgeois Gentilhomme" - "Good Heavens! For more than forty years I have been speaking prose without knowing it" - Act II. scene 4) have been using the Baysian approach without being aware of how astute we were. As the mathematical model becomes more clearly defined, it is evident that the clinician was correct when he insisted that his approach was more meaningful and appropriate than models based upon Fisherian statistics. Montesquieu was thus correct when he stated "a good doctor should know a little about everything - even medicine".