WHY WAS THIS THEORY NOT STATED BEFORE 263 



The hypothesis has been put forth gratuitously, as 

 the ancient Greeks put it forth, in the absence of a 

 definition of what constitutes life and determines the 

 origin of life. 



That life cannot be interpreted adequately in the 

 terms of physical chemistry is plain from the definite 

 limitations of physical chemistry. In the division of 

 labor, which alone now divides one science from 

 another, it is allotted to physical chemistry to work 

 with the chemical atom, the molecule, and the ion. 

 When then, for instance, membrane permeability is 

 interpreted in terms of ions of positive or negative 

 sign, in pointing out the ion (the element) and its 

 sign as the active agent, physical chemistry reaches 

 its limit. Unaided, it can go no further. But today 

 no one thinks of the chemical atom and the ion as 

 ultimate units. It bears repeating: Concerning the 

 chemical elements, it is an indisputable fact now 

 firmly established, that they are not simple but com- 

 pound, and not only compound, but trebly complex; 

 and further, that all their qualitative properties are 

 determined numerically. Elucidation of the con- 

 stitution of matter, basically considered, is furnished 

 by theoretical (mathematical) and experimental 

 physics. How then, reasonably, can one expect 

 physical chemistry to perform for biology what 

 admittedly it cannot do and is not expected to do in 



