II THEORGANISMASANOPENSYSTEM 1 47 



7. The theory of open systems has been appHed, in various forms, to quanti- 

 tative study and theory in fields such as isotope experiments, calculation of the 

 energy requirement of the steady state of the organism, growth, excitation, nerve 

 conduction, radiation biology, pharmacology, ecological systems, and others. 

 In a general way the basic physiological phenomena can be considered as con- 

 sequences of the fact that organisms are open systems. Metabolism essentially 

 the maintenance of the organism in a steady state. Irritability and autonomous 

 activities are smaller waves of processes superimposed upon the continuous flow 

 in a steady-state system. Growth, development, senescence, and death represent 

 an approach to, and slow changes of the steady state. It may be said that the 

 basic fields of physiology, such as metabolism, growth, excitation, etc. today begin 

 to be united by a common theoretical conception, namely, a theory of open 

 systems. 



8. It is worthwhile to mention that open-systems characteristics of organisms 

 are precisely those which often have been considered to be "vitalistic" and in 

 contradiction to basic laws of physics. For example, equifinality, the attainment 

 of the same final state from different initial conditions or in different ways, was 

 the first so-called "proof of vitalism" advanced by the German zoologist and 

 philosopher, Driesch (1929; cf. p. 214). This is, however, a general characteristic 

 of open systems in so far as they attain a steady state. Driesch's "second proof of 

 vitalism" was based upon the self-multiplication of biological systems (chromo- 

 somes, etc.) which probably is a consequence of their being metabolizing systems. 

 Similarly, the apparent contrast between the direction of events in inanimate and 

 in living nature was considered to be a proof of vitalism as was expressed, among 

 others, by Lecomte du Noiiy: 



"When science declares that all phenomena of the universe must obey the principle of 

 Carnot-Clausius, and we discover phenomena which do not seem to do so, we have a 

 proof that the science in question does not cover all reality, and this restricts its universality. 

 This is the case of natural evolution, which unfolds in a direction forbidden by science, i.e. 

 toward more and more improbable states. We conclude therefore that our science is 

 not universal as yet and only governs inanimate matter" (1949, p. 137). 



However, development toward states of higher order and complexity is quite 

 legitimate within the generalized thermodynamics of open systems (p. i55f.). 



The vitalists were quite correct in pointing out the fact that there are dis- 

 crepancies between the behavior of living systems and conventional physical 

 theory, i.e. physics of closed systems. These discrepancies, however, do not mean 

 that organisms violate the laws of "physics" but they disappear with the expansion 

 of physical theory, and they are, as a matter of fact, quantifiable consequences 

 of generalized physical theory including open systems {cf. Bertalanffy, 1952, 

 p. 144 ff.). 



(d) Turnover of building materials of the organism 



Modern isotope methods have presented impressive demonstration of the 

 "dynamic state" of the organism [e.g. Schoenheimer, 1942; Rittenberg, 1948). 

 By introduction of compounds marked by isotopes, the turnover rate of building 

 materials of an organism can be estimated. The labeled molecules are synthesized 



Literature p. 253 



1- 



"I 



