After the instances I have cited of actions of animals which are impossible of explanation as due to instinct, Mr. Burroughs may reply:  “Your instances are easily explained by the simple law of association.”  To this I reply, first, then why did you deny rudimentary reason to animals? and why did you state flatly that “instinct suffices for the animals”?  And, second, with great reluctance and with overwhelming humility, because of my youth, I suggest that you do not know exactly what you do mean by that phrase “the simple law of association.”  Your trouble, I repeat, is with definitions.  You have grasped that man performs what is called abstract reasoning, you have made a definition of abstract reason, and, betrayed by that great maker of theories, the ego, you have come to think that all reasoning is abstract and that what is not abstract reason is not reason at all.  This is your attitude toward rudimentary reason.  Such a process, in one of the other animals, must be either abstract or it is not a reasoning process.  Your intelligence tells you that such a process is not abstract reasoning, and your homocentric thesis compels you to conclude that it can be only a mechanical, instinctive process.

Definitions must agree, not with egos, but with life.  Mr. Burroughs goes on the basis that a definition is something hard and fast, absolute and eternal.  He forgets that all the universe is in flux; that definitions are arbitrary and ephemeral; that they fix, for a fleeting instant of time, things that in the past were not, that in the future will be not, that out of the past become, and that out of the present pass on to the future and become other things.  Definitions cannot rule life.  Definitions cannot be made to rule life.  Life must rule definitions or else the definitions perish.

Mr. Burroughs forgets the evolution of reason.  He makes a definition of reason without regard to its history, and that definition is of reason purely abstract.  Human reason, as we know it to-day, is not a creation, but a growth.  Its history goes back to the primordial slime that was quick with muddy life; its history goes back to the first vitalized inorganic.  And here are the steps of its ascent from the mud to man:  simple reflex action, compound reflex action, memory, habit, rudimentary reason, and abstract reason.  In the course of the climb, thanks to natural selection, instinct was evolved.  Habit is a development in the individual.  Instinct is a race-habit.  Instinct is blind, unreasoning, mechanical.  This was the dividing of the ways in the climb of aspiring life.  The perfect culmination of instinct we find in the ant-heap and the beehive.  Instinct proved a blind alley.  But the other path, that of reason, led on and on even to Mr. Burroughs and you and me.