Now some of these minor nervous systems in the higher animals display characteristics which enable us to compare them somewhat accurately with the whole fully developed nervous systems of certain of the lower animals which on the basis of our argument by analogy we must, and in fact usually do, agree to have corresponding with them certain lower than human forms of consciousness.
This being true, it surely follows that if any of these minor nervous systems of ours could be separated from the preeminent part of the nervous system—i. e., the brain—and still live, then these separated minor nervous systems within our bodies would have corresponding with them consciousnesses of low grade, which would be separated from what we may call the preeminent or brain consciousness, but which would nevertheless still be consciousnesses, and within the human body.
We are led then to ask whether thoroughly disconnected living minor nervous systems can under any conditions exist within the human body, and to this question we find that we must give an affirmative reply.
Suppose you were shown a frog with its head covered so that it could not be disturbed by your movements, and fastened with tapes to a board, but with both legs free.
Now if I put a drop of weak acid, say on its right knee, it would promptly rub the acid off with the back of the right foot. But suppose I fastened this right foot down with tapes, or disabled it permanently, and then again touched the right knee with acid; the right leg would struggle in the attempt to rub off the acid as it did before; but being unsuccessful because of the binding tapes or injury, after a moment of quiescence or hesitation, it would rub the acid off with the foot on the other side, i. e., the left foot. The common man would be likely to say, offhand, that the frog displayed a good deal of intelligence in this.
But now suppose I remove the head bandage and show you that the frog's head, and with it its brain, had been entirely removed. Experiments show that the frog will act in exactly the way above described if its brain is extirpated.
Now when you discovered this fact, if you made any remark, you might properly say: 'What a high degree of intelligence is involved with the mere activities of the spinal cord.' The average biologist, to be sure, usually says not this, but, rather, 'unconscious reflexes simulate the actions due to intelligence'; but I submit that he does this solely because of his preconception that the activities of the cortex of the brain are alone concerned with our conscious states.
The very argument by analogy which leads you to say that other men have consciousnesses because they act thus and so, also leads you
