And, now, lastly, the second supplementary consideration which I have to adduce is, that even in the case of a fully developed self-conscious intelligence, both receptual and pre-conceptual ideation continue to play an important part. That is to say, even in the full-summed powers of the human intellect, the three descriptions of ideation which I have distinguished are so constantly and so intimately blended together, that analysis of the adult mind corroborates the fact already yielded by analysis of the infantile mind, namely, that the distinctions (which I have been obliged to draw in order to examine the allegations of my opponents) are all essentially or intrinsically artificial. My position is that Mind is everywhere continuous, and if for purposes of analysis or classification we require to draw lines of demarcation between the lower and the higher faculties thereof, I contend that we should only do so as an evolutionist classifies his animal or vegetable species: higher or lower do not betoken differences of _origin_, but differences of _development_. And just as the naturalist finds a general corroboration of this view in the fact that structural and functional characters are carried upwards from lower to higher forms of life, thus knitting them all together in the bonds of organic evolution; so may the psychologist find that even the highest forms of human intelligence unmistakably share the more essential characters met with in the lower, thus bearing testimony to their own lineage in a continuous system of mental evolution.