298 THE PHILOSOPHY OF BIOLOGY 



and compounds, and their energy of position may have 

 become the energy of motion, but the ultimate materials 

 were still the same. What happened during the cooling 

 and contraction of the nebula was a rearrangement of 

 the elements of the system, that is, of the atoms and 

 their energies. At any moment of time the condition 

 of the system was an inevitable consequence of the 

 condition at the moment immediately preceding this, 

 and a strict functionality, in the mathematical sense, 

 existed between the two conditions. It was not more 

 complex in the later stage than in the earlier one — it 

 was merely different. Stages of evolution were really 

 phases in a transforming system of matter and energies. 

 If we choose to regard organic evolution as a 

 similar process of physico-chemical transformation, we 

 must also regard the totality of life on our earth, with 

 all the inorganic materials which interact with organic 

 things, and with all the energies, cosmic and terrestrial, 

 which also so interact, as a system in the physical 

 sense. We are now compelled to think about this 

 system in the same way as we thought about the cosmic 

 one, that is, we must postulate that a rigid mathematical 

 functionality existed between any two conditions of it, 

 and that the latter condition was inevitably determined 

 by the former one. We must think of the system as 

 at all times composed of the same elements. In its 

 later condition life may have been manifested in a 

 greater mass of material substance than in its earlier 

 conditions, but this increase of mass was only the 

 increase of one part of the system at the expense of 

 another part. At all times, then, the constitution of the 

 system was the same, and different stages of the evolu- 

 tionary process have only been different phases, or 

 arrangements, of the same elements. At no time was 

 the organic world any more or less complex than at any 



