A second field of proof of our organic relation, and one as patent as the first, is the complex specialisation of humanity.
If you find a lump of protoplasm you cannot tell whether it is a whole or a part; if you divide it, its parts make wholes and prosper as before. Very low life-forms may be cut into fragments, and each develops whatever it lacks and makes a new whole. There is little differentiation here. But if you find an eye, a tooth, a claw, you are at no loss as to whether it is a whole or a part.
If it were a whole, it would be able to maintain and reproduce itself. Being a part, it can do neither. The eye is a remote, highly developed special organ, of no use to itself; able only to serve the complex organism of which it is a part; and nourished and maintained only by that organism. This condition is absolute proof of organic life as distinguished from individual.
Apply this proof to society. Society consists of numbers of interrelated and highly specialised functions, the functionaries being individual human animals. Society develops them—they could never have been evolved in solitude. As easily conceive of independent eyes, rolling around and doing business by themselves, as of independent teachers, carpenters, dentists. Society maintains them, as the body does the eye; intricate labours of many others feeding, warming, housing, protecting the teacher, while he teaches.
Alone he might hunt, and “support himself” as a separate animal; as if, conceivably, the eye could return to a protoplasmic condition and soak up a living somehow; but as an eye it would cease to exist; and he would cease to exist as a teacher. The teacher, teaching, cannot support himself. His time, his strength, his enormously specialised skill, are spent in teaching, and the society which made him and which needs him, necessarily supports him. Teaching as an activity is not predicable of individuals. It is a power to transmit the social gain in intelligence and knowledge among the social constituents. No solitary individual could have attained this knowledge and experience; and, if he had it, he could not teach it to himself. Teaching is a social function; a very elaborate and long-developed social function. The teacher is an extreme instance of the social functionary. Other than as a social functionary he does not exist.
This test may be applied far and wide, in every trade, art, science, or business; no human occupation escapes it. Whatever a man can do separately for himself, an ape can imitate. Whatever a man does which is worth falling human is done collectively and for others, it is a social function. He may work alone at his business, but the tools he works with are the fruit of slow social evolution, and the work he does is done for others. He may retire to the forest and think alone, but he thinks on the problems of human life; no personal affairs can occupy the energies of a human brain; and the brain he thinks with is a slow social product too.
The evolution of the interdependence of social function is as clear as that of the interdependent physical functions of our separate bodies. As early animal forms have few and simple functions, gradually evolving those more delicate and complicated, so do early societies have few and simple arts or trades, and similarly evolve them. As society progresses the trades flow wider, dividing and subdividing as they go, until we have the exquisitely sublimated special skill of the modern worker; and at each step of the process the organic relation tightens as well as widens; the specialist is less able to “take care of himself,” and the others are less able to do without the specialist.
“Every man to his trade” voices our popular recognition of this law, and “Jack-of-all-trades and master of none” shows the true merit of the “all-around-man.”
We now come to a third, and in itself a fully sufficient proof of the organic nature of society—not of the social organism as a useful figure, an illustration, an analogy, but as a literal biological fact. Here are a number of separate animal bodies. Each is a group of interactive organs, each does business for itself with no need of combination with another, save in the temporary union of sex with sex, and of mother with child. These creatures are individuals. Here again is a number of apparently separate animal bodies. But each has in his head an organ which cannot perform its functions alone; an organ which for its healthful use requires contact and exchange with similar organs lodged in other bodies.
This organ is the brain. That degree of brain development which we call “human” is only found in creatures socially related; it is not individual brain power, but social. The human brain, for health and usefulness, for its normal life, requires a number of human beings with whom to feel, think, and act. We can, it is true, physically isolate a human animal, and maintain his animal life; but his human life—i. e., social life; his “feelings” and “thoughts,” the whole field of brain activity—is injured.