BOOK REVIEW

needing discrete dissertation projects, the Beyond providing a vivid portrait of Pavlov’s Physiology development of some ingenious surgical Pavlov as scientific entrepreneur, Todes Factory: Experiment, techniques allowing chronic experimenta- sheds new light on how Pavlov came to his tion on digestion, and, not least of all, theories of conditional reflex, his most en- Interpretation, hundreds of dogs, Pavlov’s favored experi- during legacy. Pavlov’s early attempt to mental subjects. Todes refers to these surgi- ‘black box’ the psyche in the physiological Laboratory Enterprise cally-altered subjects as “dog tech- processes of digestion was increasingly nologies,” which enabled researchers to thwarted by evidence that the role of psy- by Daniel P. Todes measure the production and composition chology overshadowed that of physiology. Johns Hopkins University Press of digestive juices produced under various In particular, Pavlov’s assertion that the $58.00, 512 pp, 2001 experimental conditions. This is not to say salivary gland had a “mind”—insofar as it that these organisms were could discriminate among and REVIEWED BY ANGELA N.H. CREAGER simply digestive machines: respond purposively to differ- Department of History appetite and other intangi- ent substances—was regarded Princeton University ble psychic phenomena by his prakticant Anton Princeton, New Jersey, USA were undeniably important, Teofilovich Snarskii as naive. and variation was a constant Snarskii drew on Wilhelm In 1894, Ivan Pavlov summarized the challenge in the interpreta- Wundt’s theory of recognition physiological state of knowledge about di- tion of data. As Todes shows, to argue that “psychic secre- gestion in this way: Pavlov relied on a consider- tions” did not result from voli- able interpretive flexibility tion or judgment but rather The digestive canal is in its task a com- and selective use of data to habitual reflex, set up by plex chemical factory. The raw material come up with a coherent sci- processes of association. http://www.nature.com/naturemedicine passes through a long series of institu- entific explanation of results. Pavlov’s subsequent collabora- tions in which it is subjected to certain But he also emphasized the reproducibility tor Ivan Filippovich Tolochinov further mechanical and, mainly, chemical pro- of results in his laboratory, such that even differentiated “conditional reflex” (as cessing, and then, through innumerable appetite “takes form as scientific flesh and Pavlov termed it) from unconditioned sali- side-streets, it is brought into the depot of blood, transformed from a subjective sen- vary reflexes, and showed how these two the body. […] Anatomy and physiology sation into a precise laboratory fact.” kinds of reflexes interacted. have disassembled this factor into its Pavlov’s emphasis on quantification and During this same era, developments be- component parts and have become ac- precision in physiology built on Claude yond Russia called Pavlov’s interpretation quainted with the significance of each. Bernard’s determinist philosophy of exper- of digestive control into question. William […] What is the activity of this factory at imental medicine while challenging more Bayliss and Ernest Starling’s 1902 discovery full operation, how and by what is it mechanistic modes of explanation. In par- that release of pancreatic juice was con- brought into motion, in what manner ticular, he emphasized the importance to trolled by a hormone, secretin, unsettled does one part go into operation after an- physiological explanation of adaptation, Pavlov’s longstanding preference for

© Group 2002 Nature Publishing other, in what manner does the work or “purposiveness”—the ability of the or- “nervist” control of digestion. The new bio- change in dependence upon the type of ganism to respond appropriately to specific chemistry of ferments shifted digestive re- raw material, does the entire factory al- circumstances. By 1897, Pavlov and his search towards chemical extraction and ways operate with all its parts, or not? coworkers had constructed a compelling experimentation, which was beyond account of the physiology of digestion. In Pavlov’s area of expertise. In response, Daniel P. Todes, a historian of biology and this Pavlovian picture, the nervous system Pavlov eventually decided to abandon stud- medicine at Johns Hopkins, adopts this controlled and coordinated the output of ies of digestion altogether to pursue the metaphor of the factory as the organizing digestive glands, which also responded to conditional reflex, retooling his dog tech- theme of his fascinating new book entitled different foodstuffs with specific secre- nologies towards psychological questions. Pavlov’s Physiology Factory: Experiment, tions. Appetite had a critical role as well, Todes concludes the book by briefly dis- Interpretation, Laboratory Enterprise. generating the first “psychic” phase of gas- cussing how World War I and the Bolshevik Not only does the factory suggest the tric secretions. Pavlov’s attention to the revolution disrupted Pavlov’s laboratory elaborate and precisely interlocking mech- role of appetite and his emphasis on the work. Remarkably, Pavlov’s scientific enter- anisms of digestion, Todes argues, but it is ability of the digestive glands to respond prise not only survived these massive an apt description of Pavlov’s laboratory it- differently according to type of food gave changes but grew under Lenin’s patronage self. Moving away from the nineteenth scientific validity to longstanding thera- to encompass four laboratories with large century tradition of the physiological labo- peutic traditions (such as feeding milk to teams of researchers. This epilogue fore- ratory as single-man workshop, Pavlov su- gravely ill patients) that had been inexplic- shadows the burgeoning of Pavlov’s psy- pervised a large-scale, centralized research able according to earlier mechanical theo- chological experimentation in Soviet Russia enterprise. Pavlov’s scientific achieve- ries of digestion. Pavlov also offered that will undoubtedly be further developed ments in digestive physiology—for which physicians a new therapeutic product: nat- in Todes’s upcoming biography of Pavlov. he received the 1904 Nobel Prize in ural gastric juice produced by his “factory This extensively researched and satisfying Physiology or Medicine—relied on his abil- dogs.” By World War I, proceeds from sell- book on the experimentation leading up to ity to combine and carefully manage sev- ing bottled gastric juice had increased the the 1904 Nobel prize whets the reader’s ap- eral resources: a well-furnished laboratory, laboratory budget by more than 500 per- petite for a fuller rendition of this remark- a steady stream of physicians (praktikanty) cent. able scientist’s life.

NATURE MEDICINE • VOLUME 8 • NUMBER 8 • AUGUST 2002 773