The next point to which I would direct attention is that from an objective point of view the behavior of the decerebrate animal may be in nature _intelligent_ in the empirical sense of that word. The dog that growls and snaps when his foot is pinched, tries to draw it away, and, failing that, bites at the offending hand; the “educated” dog that jumps over a hurdle, and walks on his hind legs, following a stool supporting his front legs, to my way of thinking performs intelligent actions whether it has a brain or not. If intelligence is arbitrarily limited to actions performed by conscious processes, then intelligence becomes a mere question of terms.[130] There arises also the practical difficulty that certain types of behavior, which by common assent and common sense are regarded as purely automatic and unintelligent, must be termed intelligent because guided by consciousness. I cannot help thinking that “intelligence” is a pragmatic question, not a biological or psychological one. It would be much more conducive to a clear understanding of biological problems to use intelligence only as a convenient and useful expression, like sanity or insanity, to designate certain behavior which conforms to a type which, without strictly defining its limits, popular language has defined as intelligent. Sanity and insanity have ceased to be terms of scientific value because they cannot be defined in terms of specific mental conditions and much less in terms of mental processes. So intelligence cannot be defined in terms of conscious and unconscious processes. Any attempt to do so meets with insuperable difficulties and becomes “confusion worse confounded.” When we say then that the behavior of the decerebrate dog may be intelligent, all that is meant is that the animal exhibits behavior identical with that which in the normal animal we would empirically call intelligent. In this sense unconscious processes may exhibit intelligence. It was from this viewpoint, I think, that Foster concluded: “In short, the more we study the phenomena exhibited by animals possessing a part only of their brain, the closer we are pushed to the conclusion that no sharp line can be drawn between volition and lack of volition, or between the possession and absence of intelligence. Between the muscle-nerve preparation at one limit, and our conscious willing selves at the other, there is a continuous gradation without a break; we cannot fix on any linear barrier in the brain or in the general nervous system, and say ‘beyond this there is volition and intelligence, but up to this there is none.’”[131]