THE DEFINITION OF LIFE. 



513 



the most famous of these iatro-meehanicians must 

 be named, in the first rank, Borelli ; and, next, 

 Pitcairn, Hales, Keil, and Boerhaave particularly, 

 whose influence prevailed strongly. On its side, 

 iatro-chemistry, which is but another face of the 

 doctrine of Descartes, pursued its course, and had 

 become definitely established, when modern chem- 

 istry appeared. Descartes and Leibnitz had laid 

 it down as a principle that the laws of mechanics 

 are everywhere the same ; that there is no such 

 thing as two mechanics, one for inert bodies, an- 

 other for living bodies. At the close of the last 

 century, Lavoisier and Laplace added the demon- 

 stration that there are not two chemistries either, 

 one for inert bodies and another for living bodies. 

 They proved, by course of experiment, that res- 

 piration and the production of heat take place in 

 the bodies of men and of animals, through phe- 

 nomena of combustion precisely similar to those 

 that occur in the calcination of metals. 



Nearly at the same time, Borden, Barthez, and 

 Grimaud, were famous in the school of Montpel- 

 , lier. They were Stahl's successors, yet they re- 

 tained only the first part of their master's teach- 

 ing, vitalism, and rejected its second portion, ani- 

 mism. In contradiction to Stahl, they conceive 

 that the principle of life is distinct from the soul, 

 but they agree with him in acknowledging a vital 

 force, a ruling vital principle, a unity such that it 

 explains the harmony in the manifestations of life, 

 and one that acts apart from the laws of mechan- 

 ics, physics, and chemistry. 



Still, vitalism underwent gradual modifications 

 of its form ; the docUine of vital ■properties marked 

 an important epoch in the history of physiology. 

 In place of the metaphysical notions which had 

 prevailed up to that time, we have here a physio- 

 logical idea which endeavors to explain manifes- 

 tations of life by the properties themselves of the 

 substance of the tissues or organs. As long ago 

 as at the end of the seventeenth century, Glisson 

 had pointed out irritability as the immediate 

 cause of movement in living fibre. Borden, Gri- 

 maud, and Barthez, caught a more or less uncer- 

 tain glimpse of the same idea. Haller connected 

 his name with the discovery of that mode of mo- 

 tion, by bringing to our knowledge his memorable 

 experiments on the irritability and sensibility of 

 the different parts of the body. It is, however, 

 not before the beginning of this century that Xa- 

 vier Bichat, by a sudden flash of genius, perceived 

 that the solution of vital phenomena must be 

 sought for not in an immaterial principle of a 

 higher order, but, on the contrary, in the proper- 

 ties of matter, in the depths of which these phe- 



69 



nomena have their rise and course. Doubtless 

 Bichat did not define the vital properties, but 

 gave them uncertain and obscure characteristics. 

 His genius, as is often the case, consists not in 

 having discovered the facts, but in having under- 

 stood their meaning, by being the first to announce 

 that general, luminous, and fertile idea, that in 

 physiology, as in physics, phenomena must be 

 connected with properties as with their cause. 

 " The relations of properties, as causes, to phe- 

 nomena as effects," he says, in the preface to his 

 " General Anatomy," "form an axiom almost too 

 familiar to need repetition at this day, in physics 

 and chemistry ; if my book establishes a similar 

 axiom in the physiological sciences, it will have 

 gained its end." Then he adds, in continuation : 

 " There are in Nature two classes of beings, two 

 classes of properties, two classes of sciences. Be- 

 ings are organic or inorganic, properties are vital 

 or non-vital, sciences are physical or physiologi- 

 cal." 



Here, and at the outset, it is of consequence 

 to understand Bichat's idea thoroughly. It might 

 be supposed that he means to side with the phys- 

 icists and chemists, because he agrees with them 

 in placing the causes of phenomena in the proper- 

 ties of matter; but the result is the opposite one, 

 and Bichat abandons and separates himself from 

 them in as thorough a way as possible. In truth, 

 the object pursued at all times by the iatro-mech- 

 anicians, physicists, ©r chemists, has been to 

 prove a similarity — an identity — between the phe- 

 nomena of living bodies and those of inorganic 

 bodies. Bichat, in direct opposition to them, lays 

 down as a principle that vital properties are ab- 

 solutely opposed to physical properties, so that, 

 instead of going over into the camp of the physi- 

 cists and chemists, he remains a vitalist, with 

 Stahl and the school of Montpellier. With them, 

 he conceives that life is a conflict between con- 

 tending activities ; he admits that the vital prop- 

 erties preserve the living body, by counteracting 

 the physical properties that tend to destroy it. 

 When death occurs, it is nothing but the triumph 

 of physical properties over their opponents. 

 Moreover, Bichat summarizes his ideas complete- 

 ly in the definition he gives of life : " Life is the 

 group of functions that resist death ; " which 

 means, in other words, life is the group of vital 

 properties which resist physical properties. 



This view, which consists in regarding vital 

 properties as a sort of metaphysical entities, not 

 capable of clear definition, except as opposed to 

 common physical properties, no doubt led inves- 

 tigators into the same mistakes that the other 



