The Second Postulate of the Theory 311 



trust in the retrospective formulas the tying of past 

 threads in knots. For the event now present rides by us 

 and becomes past ; and the very threads we assayed to trace 

 with pains and failure, become those which form the back- 

 ward fringe, and constitute history. The whole forms a chain. 

 Experience is continuous. Our discoveries that events 

 now gone, experiences now no more than memories, still 

 fit into what we call the categories of knowledge - - these 

 discoveries are no more valid, from the point of view of 

 genesis, than are the expectations and prophecies, which 

 we perforce must also indulge, respecting the future 

 which issues from the present. 



So there is a genetic science, as there is a prospective atti- 

 tude - - a science of development and evolution. It is of the 

 knowledge series which we are not able to read both ways, 

 or which, if read both ways, has for each a different for- 

 mula, that the term genetic is properly used. 



5. The Second Postulate of the Theory of Genetic Modes 



We may write down, accordingly, as the second or posi- 

 tive postulate of the ' theory of genetic modes,' that that 

 series of events only is truly genetic vvJiich cannot be con- 

 structed before it has Jiappcned, and which cannot be ex- 

 Jiausted by reading backwards after it has happened. 



To be sure we often apply the term genetic to all cases 

 in which history is involved ; cases in which there is a 

 regular series of changes. But there are several cases of 

 this. 



If a series of events so exhausts itself that we may 

 begin it over again and find the terms one by one again 

 following their aforetime sequence, then this is not truly 



