If the Heringian view is accepted, that heredity is only a mode of memory, and an extension of memory from one generation to another, then the repetition of its development by any embryo thus becomes only the repetition of a lesson learned by rote; and, as I have elsewhere said, our view of life is simplified by finding that it is no longer an equation of, say, a hundred unknown quantities, but of ninety-nine only, inasmuch as two of the unknown quantities prove to be substantially identical. In this case the inheritance of acquired characteristics cannot be disputed, for it is postulated in the theory that each embryo takes note of, remembers and is guided by the profounder impressions made upon it while in the persons of its parents, between its present and last preceding development. To maintain this is to maintain use and disuse to be the main factors throughout organic development; to deny it is to deny that use and disuse can have any conceivable effect. For the detailed reasons which led me to my own conclusions I must refer the reader to my books Life and Habit and Unconscious Memory, the conclusions of which have been often adopted, but never, that I have seen, disputed. A brief résumé of the leading points in the argument is all that space will here allow me to give.
We have seen that it is a first requirement of heredity that there shall be physical continuity between parents and offspring. This holds good with memory. There must be continued identity between the person remembering and the person to whom the thing that is remembered happened. We cannot remember things that happened to someone else, and in our absence. We can only remember having heard of them. We have seen, however, that there is as much bona-fide sameness of personality between parents and offspring up to the time at which the offspring quits the parent’s body, as there is between the different states of the parent himself at any two consecutive moments; the offspring therefore, being one and the same person with its progenitors until it quits them, can be held to remember what happened to them within, of course, the limitations to which all memory is subject, as much as the progenitors can remember what happened earlier to themselves. Whether it does so remember can only be settled by observing whether it acts as living beings commonly do when they are acting under guidance of memory. I will endeavour to show that, though heredity and habit based on memory go about in different dresses, yet if we catch them separately—for they are never seen together—and strip them there is not a mole nor strawberry-mark nor trick nor leer of the one, but we find it in the other also.
What are the moles and strawberry-marks of habitual action, or actions remembered and thus repeated? First, the more often we repeat them the more easily and unconsciously we do them. Look at reading, writing, walking, talking, playing the piano, etc.; the longer we have practised any one of these acquired habits, the more easily, automatically and unconsciously, we perform it. Look, on the other hand, broadly, at the three points to which I called attention in Life and Habit:—
I. That we are most conscious of and have most control over such habits as speech, the upright position, the arts and sciences—which are acquisitions peculiar to the human race, always acquired after birth, and not common to ourselves and any ancestor who had not become entirely human.
II. That we are less conscious of and have less control over eating and drinking [provided the food be normal], swallowing, breathing, seeing, and hearing—which were acquisitions of our prehuman ancestry, and for which we had provided ourselves with all the necessary apparatus before we saw light, but which are still, geologically speaking, recent.
III. That we are most unconscious of and have least control over our digestion and circulation—powers possessed even by our invertebrate ancestry, and, geologically speaking, of extreme antiquity.
I have put the foregoing very broadly, but enough is given to show the reader the gist of the argument. Let it be noted that disturbance and departure, to any serious extent, from normal practice tends to induce resumption of consciousness even in the case of such old habits as breathing, seeing, and hearing, digestion and the circulation of the blood. So it is with habitual actions in general. Let a player be never so proficient on any instrument, he will be put out if the normal conditions under which he plays are too widely departed from, and will then do consciously, if indeed he can do it at all, what he had hitherto been doing unconsciously. It is an axiom as regards actions acquired after birth, that we never do them automatically save as the result of long practice; the stages in the case of any acquired facility, the inception of which we have been able to watch, have invariably been from a nothingness of ignorant impotence to a little somethingness of highly self-conscious, arduous performance, and thence to the unselfconsciousness of easy mastery. I saw one year a poor blind lad of about eighteen sitting on a wall by the wayside at Varese, playing the concertina with his whole body, and snorting like a child. The next year the boy no longer snorted, and he played with his fingers only; the year after that he seemed hardly to know whether he was playing or not, it came so easily to him. I know no exception to this rule. Where is the intricate and at one time difficult art in which perfect automatic ease has been reached except as the result of long practice? If, then, wherever we can trace the development of automatism we find it to have taken this course, is it not most reasonable to infer that it has taken the same even when it has risen in regions that are beyond our ken? Ought we not, whenever we see a difficult action performed automatically, to suspect antecedent practice? Granted that without the considerations in regard to identity presented above it would not have been easy to see where a baby of a day old could have had the practice which enables it to do as much as it does unconsciously, but even without these considerations it would have been more easy to suppose that the necessary opportunities had not been wanting, than that the easy performance could have been gained without practice and memory.
When I wrote Life and Habit (originally published in 1877) I said in slightly different words:—
“Shall we say that a baby of a day old sucks (which involves the whole principle of the pump and hence a profound practical knowledge of the laws of pneumatics and hydrostatics), digests, oxygenizes its blood—millions of years before anyone had discovered oxygen—sees and hears, operations that involve an unconscious knowledge of the facts concerning optics and acoustics compared with which the conscious discoveries of Newton are insignificant—shall we say that a baby can do all these things at once, doing them so well and so regularly without being even able to give them attention, and yet without mistake, and shall we also say at the same time that it has not learnt to do them, and never did them before?
“Such an assertion would contradict the whole experience of mankind.”