The questionable medical practice of German neurologist Dr. Oskar Vogt extends from the 1890's to WW II--and by chronicling those decades in his knowledgeable, droll, and spirited first novel, Spengler offers an entertainment following Europe's history from last century's end to the moment before Nazi defeat. Not a Freudian he, from the outset of his career Dr. Vogt believes genius is a physiological presence in the brain that can be discovered through dissection and analysis--and so his fin-de- siäcle lament may be understandable that ``at a time like ours...there is a general shortage of elite brains available for scientific research.'' To support himself in the highly competitive medical world, Vogt treats neurasthenia--particularly in well-off patients like Margarethe Krupp (of the great industrialist family), whose husband's consuming homosexuality threatens to bring about family scandal and confusion--and reveals Dr. Vogt's ability to survive and flourish by such means as may be available. The times move forward as Dr. Vogt attempts to do the same himself: the reader first glimpses Lenin at an intellectual gathering outside Geneva in 1905; WW I comes and goes (``The recent war was a disgrace as far as brains are concerned''); Bolshevism triumphs; and with the death of Lenin in 1924, it is the by-then-renowned Dr. Vogt who is called upon to make 30,000 microscopic slides from frontal slices of the great leader's brain (``I've never seen such collapsed convolutions'')--with political results that will later lead to richly absurd comedies of jealousy, suspicion, espionage, and paranoia as Russia and Germany draw apart in preparation for WW II, with the aging Dr. Vogt caught up--and dropped (``No, Vogt had really become superfluous'')--by ideological forces as absurd at bottom as his own scientific theories had ever been. If not always limpid in the reading, a brilliantly tapestried and deadpan look at a half-century possibly as hilarious as it was mad.