of the human body, if looked at by itself, could have 

 constituted a problem that nobody could approach" ($ 90) . 

 Pavlov recommended to proceed always from simple phenomena to 

 the more complicated. Man, Pavlov said, is a microcosm; 

 in him, as in the depth of nature, where there are four life 

 forms, there is a fourfold life period, namely the life of 

 minerals, plants, animals, and finally the intellectual life, 

 or the human life. In a footnote ($ 92), Pavlov said that 

 for the most brilliant work reviewing this question we are 

 indebted to the great professor of the Petersburg University, 

 Jakob Kaydanow C44) . This work was published under the title, 

 "The Fourfold Property of Life, of the differences and 

 reciprocal connections of the four main types of life, which 

 are discussed in general and in relation to man in particu- 

 lar." 39 Following him in importance is I. M. Boldryev (45), 

 at that time professor of anatomy and physiology of the 

 Imperial Moscow Medical-Surgical Academy, with his dissertation 

 "On the Features of Plant or Organic Life." 40 Speaking of 

 man as a microcosm for the depth of nature, Pavlov followed 

 the terminology of Kaydanow. Human nature, Pavlov said, 

 citing Kaydanow, could have remained much less available to 

 our understanding if animals did not exist, whose nature is 

 discovered in the life of plants, and the nature of the 

 latter in the life of minerals. "And so," he continued, 

 "there is no doubt that for the thorough investigation of 

 the truth there is a route leading from the simple to the 

 complex, i.e. as if from the known to the unknown" ($ 93). 

 So far as man and infusoria designate the extreme degrees 

 in the limits of perfection of the animal organism, and so 

 far as in nature nothing is done by leaps, so "it is hardly 

 possible to imagine that man had occupied the highest of 

 these steps without going through (not touching) the lower" 

 94). 



39. Jacob Kaydanow, TETRACTYS VITAE SEU DE DIFFERENTIA 

 MUTUAQUE CONTINUITATE IV CARDINALIUM FORMARUM 

 VITAE, GENERATIM CONSIDERATAE , HOMINIS PRAECIQUE 

 St. Petersburg, 1813, 107 pp. 



40. J. Boldyrev, "De characteribus vitae vegetativae seu 

 organicae principalibus ej usque praecique et animalibus 

 in nomine differentia." Moscow, 1815, 27 pp. 



168 



