Highest in the scale, and notably in man, occurs that kind of response to stimulation which is known as Reason, and which may be defined as "the faculty which is concerned in the conscious adaption of means to ends," by virtue of acquired non-inherited knowledge and ways of thinking and acting. Though powers of acquiring reason are transmissible, reason itself is obviously never transmitted.
I am aware that the above definitions of instinct and reason are very different from those ordinarily accepted, but I think it will be found on consideration that they are more accurate, that they more completely include within their limits all cases of instinct and reason respectively, and that they more clearly separate that which is instinctive from that which is rational than any other definition as yet advanced. Professor Romanes, for example, defines reason as—
"The faculty which is concerned in the conscious adaption of means to ends. It therefore implies the conscious knowledge of the relation between means employed and ends attained, and may be exercised in adaption to circumstances novel alike to the experience of the individual and to that of the species."—Mental Evolution, p. 318.
But it appears to me that reason so defined includes nearly all those actions which we commonly term instinctive. For instance, by what term shall we designate the action of the spider when he builds his web? Does the animal not know for what purpose he constructs it? Was there ever a web building in which there were not "circumstances novel alike to the experience of the individual and to that of the species"? Or, when he runs along a thread to capture his prey, or cuts loose a dangerous captive, does he not consciously adapt means
