The Evidence of Mind 35 



rubric he maintains that "individual purposiveness " is char- 

 acteristic of the movements from which consciousness may 

 be inferred; that individual purposiveness pertains only to 

 voluntary acts, and that voluntary acts are acts "which are 

 preceded by the intention to perform a definite movement, 

 hence by the idea of this movement." We have reached the 

 same conclusion in the preceding paragraph. The third test 

 of the presence of consciousness, the teleological test, rests 

 on the consideration: "What significance for the organism 

 may be possessed by the production of a conscious effect by 

 certain stimuli ? " (252). This test, however, being of a purely 

 a priori character, would seem to be distinctly less valuable 

 than the others. 



Yerkes proposes "the following six criteria in what seems 

 to me in general the order of increasing importance. The 

 functional signs are of greater value as a rule than the struc- 

 tural ; and within each of the categories the particular sign is 

 usually of more value than the general. In certain cases, 

 however, it might be maintained that neural specialization is 

 of greater importance than modifiability. 

 I. Structural Criteria. 



1. General form of organism (Organization). 



2. Nervous system (Neural organization). 



3. Specialization in the nervous system (Neural spe- 



cialization). 

 II. Functional Criteria. 



1. General form of reaction (Discrimination). 



2. Modifiability of reaction (Docility). 



3. Variability of reaction (Initiative)" (463). 



The terms "discrimination," "docility," and "initiative" 

 in this connection are borrowed from Royce's "Outlines of 

 Psychology " (372). 



If resemblance of nervous and sense-organ structure to the 



