REASON. 319 



the best that I can find, and therefore it will be understood 

 that in my usage, while all acts of reason are likewise acts of 

 inference, all acts of inference need not be acts of reason. 



Thus much as to terminology being premised, I may pass 

 to the subject of the present chapter. I have already, in 

 earlier chapters, endeavoured to show how it is probable that 

 consciousness arises out of reflex action (or that the mind- 

 element becomes attached to nervous processes of adjustment), 

 when the latter arrives at such a degree of complexity, or has 

 reference to external circumstances having such a degree of 

 inconstancy, that the nerve-centre becomes a seat of com- 

 parative turmoil among molecular forces. Whenever this 

 stage is reached, and a nerve-centre begins to become con- 

 scious of its own working, we pass, according to my classifi- 

 cation, from the domain of reflex action into that of instinct 

 — instinct being, in my terminology, reflex action into which 

 there is imported the element of consciousness. But now, as 

 during the course of evolution the lower forms of life are 

 required progressively to adjust their actions to circum- 

 stances of growing complexity and inconstancy, or to occasions 

 of growing infrequency, it follows that the organized instincts 

 with which they are endowed must at some point begin to 

 become inadequate; a greater flexibility in the power of 

 adjustive response is needed, and if any such flexibility is 

 possible under the conditions of ganglionic action, those 

 individuals which best attain to it will survive, and so the 

 improvement will become general to the species. Now we 

 know that such an increase of flexibility is possible under 

 the conditions of ganglionic action, and this increase of 

 flexibility on its subjective side we know as the faculty of 

 reason. It is here needful to consider in what this faculty 

 consists. 



While treating of the genesis of Perception I pointed out 

 that the faculty admits of numberless degTces of elaboration. 

 These we found to depend largely, or even chiefly, upon the 

 degree of complexity presented by the objects or relations 

 perceived. Now when a perception reaches a certain degree 

 of elaboration, so that it is able to take cognizance of the 

 relation between relations, it begins to pass into reason, or 

 ratiocination. Contrariwise, in its highest stages of develop- 

 ment, ratiocination is merely a highly complex process of 

 perception — i.e., a perception of the equivalency of perceived i 



