Men like Maeterlinck, Fabre, Thoreau, and Burroughs have given the most painstaking and careful attention to the life and psychology of ants, spiders, beavers, horses, dogs, and even birds. What is the sum of their discoveries? They have found that these creatures of the animal kingdom, although unable to think and reason as creatures of the human kingdom do, nevertheless exercise an unerring intelligence, seemingly automatic and hereditary though it be, an intelligence which we call instinct.
Ants and termites closely organize themselves into a wonderful society where each has his appointed task and where all work individually with soldierly discipline and indefatigable industry for the common benefit, as is demonstrated by the way they store food for future communal use and the expert way in which they practise the art of warfare. Beavers build their dams across streams with the accuracy and ingenuity of skilled engineers. Large flocks of birds migrate with unfailing regularity to the same spot in some distant country every year, never losing their correct direction. A wild creature roaming the jungles will not touch poisonous plants, however hungry it be. A spider spins a web for its prey with the calculated accuracy of a mathematician and the refined grace of an artist. Nobody dare deny that some kind of intelligence, some activity of mind guides and directs multitudes of creatures all over the world and shows them how to feed and support themselves and their young, how and when to store food for the winter months, how to cure themselves when ill, what are the nourishing foods for them to take, and so on.
When however we ask in what way this animal mind compares with that of human beings, we soon observe one important difference. Science has ascertained that Nature invariably evolves a new bodily organ to perform a needed physical function: thus there was a time in the misty past when all creatures had no ears but grew them as the necessity of hearing sounds became more and more urgent. It was Nature's adaptation to inner need. There is one function which animals do not share in common with human beings and that is speech. They do not possess that delicate and intricate organ, the larynx. This is quite clearly because they do not feel the need of it. Even our primitive ancestors were once at the stage when they too were larynxless. Now language is the product of speech and came into belated being after men wished to communicate with other men. What is speech but uttered thoughts? And what are thoughts but the product of the working of intellect? And what is intellect but, to take the definition given in our first volumes, "the activity of logical thinking"? But logical thinking cannot be performed without using words. And words cannot be spoken without the possession of a larynx. If therefore Nature has failed to make the physical gesture of growing a larynx, it is because the mental needs of logical thinking have not compelled it, that is, such thinking is absent.
Many animals can see smell hear and taste with much greater acuteness than humans, but none of them can utter those magical words which will make a logically constructed thought known to another animal; none can frame words into phrases and then formulate the latter into sentences. The absence of spoken language among animals is itself a proof that they are not the ratiocinative creatures which human beings are. The splendid but limited intelligence they show and the remarkable perception of how and when to act which they possess are sufficiently remarkable to impress observers, but they are not the results of the same logical faculty which man uses; they are the results of a subconscious instinctive mental working. We admit this when we refer to it as "instinct." An animal submits to the guidance of this subconscious mind and does not balance up the pros and cons of a matter requiring decision, as the human's logical mind does. Some higher animals, like the elephant, the lemur, and the ape, may not conform to this description. But this is merely because they mark a transitional stage in evolution and are close enough to the human kingdom to exhibit exceptional traits. They have begun to manifest special characteristics of their own, to break away from the herd imprint, and thus to show that individuality which is a mark of man. This individual self-consciousness which man alone possesses in its fullness is the fruit of his possession of self-conscious intellectual processes.
-- Notebooks Category 7: The Intellect > Chapter 5 : Semantics > # 144
