The Psychological and the Biological 7 



into another is necessary to the notion. We are justified, 

 therefore, in finding a force in a set of phenomena only 

 when we are able to find a continuous process of change 

 taking place in a continuous sort of material. Given the 

 material of this science or that, — the arbitrarily selected 

 domain of observation, — we may then find forces of which 

 this science may take cognizance when and only when the 

 antecedent is followed by the same subsequent phenomenon, 

 both in this sort of material. This, as is said above, holds 

 so long as we restrict ourselves to a Hmited domain of facts. 

 For example, in an earHer discussion, cited above, the ques- 

 tion is that of the definition of the social. We find that 

 various sorts of 'forces,' vital, physical, even chemical, 

 and, by way of climax, changes due merely to the absence 

 of certain usual conditioning Umitations — all these have 

 been called * social forces.' But when we distinguish ' social 

 forces ' as * social producers of change in social material,' 

 we are then able to subordinate all the other loosely recog- 

 nized agencies, putting them under the heading of ' condi- 

 tions ' — modifying, limiting, and directing conditions — 

 under which the truly social forces operate. 



So it is in each science. I have suggested that the term 

 * nomic ' be applied to such conditio?ts considered with 

 reference, in each case, to the true set of forces whose play 

 they condition. The 'socionomic' agencies, forces, etc., 

 using again the same illustration, condition the opera- 

 tion of the forces which are truly social. 



Carrying out the same distinction in this present connec- 

 tion, we have analogous results. Psychology finds certain 

 continuous processes of change, certain psychic states 

 antecedent upon certain other subsequent psychic states. 

 These, in accordance with the distinction suggested, we may 



