The First Postulate of tlie Theory 303 



vitiating element in most attempts to construct a scien- 

 tific view of the world. In the language of our earlier 

 distinction, they make the retrospective exhaustive, and 

 use only static formulas for the phenomena which are 

 essentially genetic, prospective, and dynamic. This pro- 

 cedure employs a mental shorthand which is correct so 

 far as it goes, and which is quite right in its demand that 

 phenomena, to be natural at all, shall fulfil its statements ; 

 but it fails to recognize the possibility that these same 

 phenomena may be yet more may fulfil requirements of a 

 genetic sort which such formulas do not construe nor 



recognize. 



This outcome it is which I wish to set down as the first 

 or negative postulate of what is here called the ' theory of 

 genetic modes! This postulate may be stated as follows: 

 the logic of genesis is not expressed in convertible proposi- 

 tions. Genetically A = B ; but it does not follow that 

 B = A. In its material application this takes on two 

 forms : first, if xy is invariably followed by z, it does not 

 follow (i) that z is invariably preceded by xy, nor (2) that 

 nothing more than z invariably arises subsequently to xy. 

 In the language of chemistry these two points read : 

 granted that oxygen and hydrogen produce water, it does 

 not f ollow( I ) that water may not be produced by something 

 else than oxygen and hydrogen, nor (2) that if the water 

 be reduced to oxygen and hydrogen again, something else 

 than water may not have been produced and again de- 

 stroyed along with the water. 



This, some one may object, traduces the law of cause 

 and effect as generalized in the formula for the conser- 

 vation of energy. Not so ; but it does traduce certain 

 illegitimate extensions of that law. It says explicitly 



