Wherever the organism forms a whole as to its vitality, whether it be an amoeba or a man, the struggle is for the maintenance of that whole or of that particular individual organism. All the structures and functions go to the preservation of that individuality, or of that individual organic self, constituting the impulse of self-preservation in the total activity of the particular individual organism. The great number of physico-chemical and mechanical processes, adaptations and adjustments of inner structures and functions, as well as the different reactions to the stimuli of external environment, even in the lowest of micro-organisms, are for the whole of the individuality.
When organisms take to forms of social life the fundamental aim is still the protection or self-preservation of the individual. The community is an additional defense of the individual against a hostile environment. Thus the herds of Damara cattle, or of social aggregates of other animals, offer greater protection to each individual animal. The individual wolf running in packs has more power for attack and defense. The individual man has more forces for aggression and for protection by living in a social medium which provides the individual with more sensory organs for observation of danger and with more organs for defense and attack, than in isolated states. The herd, the pack, the horde, the society are for the self-preservation of the individual.
It has been shown on good grounds that the very sense of external reality has become intensified in the individual by his capacity of living in a social aggregate. The social aggregate strengthens each individual member of the group. The individual is not for the group, but the group is for self-preservation of the individual. Should the individual lose his self-protection, or even have his impulse of self-preservation lowered, the whole aggregate faces ultimate destruction. That is why when in a social aggregate the impulse of self-preservation becomes limited, inhibited, and lowered by tyranny of social commandments, society is sure to decline, degenerate, and finally dissolve; or fall a victim to an external invader,—the fate of tribes, communities, and nations in the past and the present. The moving power of life is self-preservation of the individual.
A close study of life in general and of animal life in particular brings one to the inevitable conclusion that life in all its forms has self-preservation as its fundamental principle. Self-preservation is the main impulse, the prime mover of life. The prime mover of life is not the impulse of species preservation, or of sex, but the impulse of self-preservation of the individual organism.
Self-preservation has two aspects, the positive and the negative. In the positive form the primitive impulse is to keep the individual alive, to keep the functions and structure in normal condition, to conduce to the full development and harmonious activity of the individual. The negative form of the preservative impulse is the preservation from injury, degeneration, destruction, and death. This negative aspect of the impulse of self-preservation expresses itself in the higher animals in the form of fear.
The fear instinct is an essential constituent of the impulse of life. We may call the fear instinct the guardian of all sentient being. Wherever there is the least scent or even the least suggestion of danger, there the instinct of fear is aroused. Fear is the companion following close on the heels of the impulse of self-preservation.
Since every animal is always surrounded by enemies, and since every strange thing or strange occurrence is a menace or possible signal of danger, the fear instinct is aroused on all strange occasions. The fear instinct requires the slightest stimulus to start into function.
While most of the instincts require special conditions, and are usually periodic, the fear instinct is ever present and can be awakened on all occasions, and under any circumstances. Anything unfamiliar,—darkness, a state of exhaustion, weakness, fatigue, arouses the fear instinct, startling the animal into running, hiding, crouching, and preparation for attack or defense.
The fear instinct stays with us, and watches over us day and night. It follows us closely in our active, waking life, attends us in our resting hours, and watches over us in our sleeping periods. The fear instinct is the last to fall asleep, and the first to awake. The fear instinct follows us like our shadow, with the only difference that it constantly affects our actions, hardly ever leaves us alone, and keeps steady vigilance over our life activities. The reason for this apparently strange companionship is the fact that the fear instinct is the primitive instinct of the life impulse, the impulse for self-preservation.
The overwhelming intensity of the fundamental impulse of self-preservation is well described by the great writer Dostoevsky, whose insight into the psychology of human life and especially into abnormal mental life transcends that of any other writer: “Where is it I have read that someone condemned to death says or thinks, an hour before his death, that if he had to live on some high rock, on such a narrow ledge that he had only room to stand, and the ocean, everlasting darkness, everlasting solitude, everlasting tempest around him, if he had to remain standing on a square yard of space all his life, a thousand years, eternity, it were better to live so than to die at once! Only to live, to live, and live! Life whatever it may be!”