Ever very truly,
Lafcadio Hearn.
TO BASIL HALL CHAMBERLAIN
April, 1895.
Dear Chamberlain,—Excuse me if I don’t reply more fully to your letter, because my eyes are a little tired. I can only say I wish I were sick, somewhere near you: then perhaps you would come and see me, and talk more of these queer things. You would not find the time heavy. For the subject is a romance.
In order to convey by a diagram any picture-idea of what heredity means, one should have to draw a series of inverted cone-figures representing a reticulation of millions of cross-lines. This could only be done well under a microscope, and on a very limited scale. Because the thing goes by arithmetical progression. The individual is the product of 2, the 2 of 4, the 4 of 8, the 8 of 16—well, you know the tale of the smith who offered to shoe a horse with 32 nails, to receive 1 cent on the first nail, and to double the sum upon every nail! The enormity of inheritance is at once apparent. But to produce another individual, another life is needed, which represents the superimposition in the child of another infinitely complex inheritance. The fact is only worth stating as suggesting that under normal circumstances the child would necessarily represent an increment. He should receive not only the experience of his father’s race, but all that of his mother’s race superimposed upon it. The fact that he does very nearly do so is evidenced by the reappearance in his descendants of parental traits always invisible in himself. Mere multiplication ought therefore to account for a larger mental growth and progress than exists or could ever exist.
Why doesn’t it? Simply because in the brain the same selective process goes on as in the vegetable world. As out of 10,000,000 seeds scarcely one survives: so out of a million mental impressions scarcely one survives. Indeed, not so many. For the inheritance is of repetitions,—rarely of single impressions. It is only when an impression has been repeated times innumerable that it becomes transmissible,—that it affects the cerebral structure so as to become organic memory. The inheritance is of a very compound nature, therefore,—requiring either enormous time for development, or enormous experience. There is reason to believe, however, that in the case of very highly organized brains,—such as those of the modern musician, linguist, or mathematician,—the multiple experiences of even one lifetime may produce structural modifications capable of transmission. This is not the case except in men as much larger than common men as Fuji is larger than an ant-hill. And the reason is that such a brain can daily receive billions of impressions that common minds cannot receive in a whole lifetime. The thinking is of the constructive character,—the most highly complex form possible; and the extreme sensitiveness of the structures renders habitual conceptions which represent combinations of conscious states never entered into before. Measured by mere difference of force, the brain of the mathematician is to the brain of the ordinary man as the most powerful dynamo to the muscles of an ant.
Happily for mankind, not only is inheritance something more than repetition, it is also something less than repetition. Between these two extremes of plus and minus the physiology of mental activities in any lifetime represents a fierce struggle for the survival of the best or worst. Here is where the environment comes in,—determining which of a million tendencies shall have freest play or least play. According to circumstances the impulses of the dead are used or neglected. The more used, the more powerful their active potentialities, and the more apt to increase by transmission. But their vitality is racial—measurable only by millions of years. They may lie dormant for twenty centuries, and be suddenly called into being again—sinister and monstrous-seeming, because no longer in harmony with the age. (Here is the point of the selective process.)
Here comes in the consideration of a very terrible possibility. Suppose we use integers instead of quintillions or centillions, and say that an individual represents by inheritance a total of 10—5 of impulses favourable to social life, 5 of the reverse. (Such a balance would really occur in many cases.) The child inherits, under favourable conditions, the father’s balance plus the maternal balance of 9,—four of the number being favourable. We have then a total which becomes odd, and the single odd number gives preponderance to an accumulation of ancestral impulse incalculable for evil. It would be like a pair of scales, each holding a mass as large as Fuji. If the balance were absolutely perfect, the weight of one hair would be enough to move a mass of millions of tons. Here is your antique Nemesis awfully magnified. Let the individual descend below a certain level, and countless dead suddenly seize and destroy him,—like the Furies.
In all cases, however, except those of the very highest forms of mental activity, the psychological life consists of repetitions,—not of originalities. And environment, chance, etc., simply influence the extent and volume of the repetitions. In the case of constructive imagination, on the other hand, there are totally new combinations made independently of environment or circumstances: there is almost creation, and in certain cases absolute faculty of prediction. Instance the case of the mathematician who, without having ever seen the Iceland Spar, but knowing its qualities, said: “Cut it at such an angle, and you will see a coloured circle.” They cut it, and the circle was seen for the first time by human eyes.