Nor yet does personality depend upon any consciousness or sense of such personality on the part of the creature itself—it is not likely that the moth remembers having been a caterpillar, more than we ourselves remember having been children of a day old. It depends simply upon the fact that the various phases of existence have been linked together, by links which we agree in considering sufficient to cause identity, and that they have flowed the one out of the other in what we see as a continuous, though it may be at times, a troubled stream. This is the very essence of personality, but it involves the probable unity of all animal and vegetable life, as being, in reality, nothing but one single creature, of which the component members are but, as it were, blood corpuscles or individual cells; life being a sort of leaven, which, if once introduced into the world, will leaven it altogether; or of fire, which will consume all it can burn; or of air or water, which will turn most things into themselves. Indeed, no difficulty would probably be felt about admitting the continued existence of personal identity between parents and their offspring through all time (there being no sudden break at any time between the existence of any maternal parent and that of its offspring), were it not that after a certain time the changes in outward appearance between descendants and ancestors become very great, the two seeming to stand so far apart, that it seems absurd in any way to say that they are one and the same being; much in the same way as after a time—though exactly when no one can say—the Thames becomes the sea. Moreover, the separation of the identity is practically of far greater importance to it than its continuance. We want to be ourselves; we do not want any one else to claim part and parcel of our identity. This community of identities is not found to answer in everyday life. When then our love of independence is backed up by the fact that continuity of life between parents and offspring is a matter which depends on things which are a good deal hidden, and that thus birth gives us an opportunity of pretending that there has been a sudden leap into a separate life; when also we have regard to the utter ignorance of embryology, which prevailed till quite recently, it is not surprising that our ordinary language should be found to have regard to what is important and obvious, rather than to what is not quite obvious, and is quite unimportant.
Personality is the creature of time and space, changing, as time changes, imperceptibly; we are therefore driven to deal with it as with all continuous and blending things; as with time, for example, itself, which we divide into days, and seasons, and times, and years, into divisions that are often arbitrary, but coincide, on the whole, as nearly as we can make them do so, with the more marked changes which we can observe. We lay hold, in fact, of anything we can catch; the most important feature in any existence as regards ourselves being that which we can best lay hold of rather than that which is most essential to the existence itself. We can lay hold of the continued personality of the egg and the moth into which the egg develops, but it is less easy to catch sight of the continued personality between the moth and the eggs which she lays; yet the one continuation of personality is just as true and free from quibble as the other. A moth becomes each egg that she lays, and that she does so, she will in good time show by doing, now that she has got a fresh start, as near as may be what she did when first she was an egg, and then a moth, before; and this I take it, so far as I can gather from looking at life and things generally, she would not be able to do if she had not travelled the same road often enough already, to be able to know it in her sleep and blindfold, that is to say, to remember it without any conscious act of memory.
So also a grain of wheat is linked with an ear, containing, we will say, a dozen grains, by a series of changes so subtle that we cannot say at what moment the original grain became the blade, nor when each ear of the head became possessed of an individual centre of action. To say that each grain of the head is personally identical with the original grain would perhaps be an abuse of terms; but it can be no abuse to say that each grain is a continuation of the personality of the original grain, and if so, of every grain in the chain of its own ancestry; and that, as being such a continuation, it must be stored with the memories and experiences of its past existences, to be recollected under the circumstances most favourable to recollection, i.e., when under similar conditions to those when the impression was last made and last remembered. Truly, then, in each case the new egg and the new grain is the egg, and the grain from which its parent sprang, as completely as the full-grown ox is the calf from which it has grown.
Again, in the case of some weeping trees, whose boughs spring up into fresh trees when they have reached the ground, who shall say at what time they cease to be members of the parent tree? In the case of cuttings from plants it is easy to elude the difficulty by making a parade of the sharp and sudden act of separation from the parent stock, but this is only a piece of mental sleight of hand; the cutting remains as much part of its parent plant as though it had never been severed from it; it goes on profiting by the experience which it had before it was cut off, as much as though it had never been cut off at all. This will be more readily seen in the case of worms which have been cut in half. Let a worm be cut in half, and the two halves will become fresh worms; which of them is the original worm? Surely both. Perhaps no simpler case than this could readily be found of the manner in which personality eludes us, the moment we try to investigate its real nature. There are few ideas which on first consideration appear so simple, and none which becomes more utterly incapable of limitation or definition as soon as it is examined closely.
Finally, Mr. Darwin (“Plants and Animals under Domestication,” vol. ii. p. 38, ed. 1875), writes—
“Even with plants multiplied by bulbs, layers, &c., which may in one sense be said to form part of the same individual,” &c., &c.; and again, p. 58, “The same rule holds good with plants when propagated by bulbs, offsets, &c., which in one sense still form parts of the same individual,” &c. In each of these passages it is plain that the difficulty of separating the personality of the offspring from that of the parent plant is present to his mind. Yet, p. 351 of the same volume as above, he tells us that asexual generation “is effected in many ways—by the formation of buds of various kinds, and by fissiparous generation, that is, by spontaneous or artificial division.” The multiplication of plants by bulbs and layers clearly comes under this head, nor will any essential difference be felt between one kind of asexual generation and another; if, then, the offspring formed by bulbs and layers is in one sense part of the original plant, so also, it would appear, is all offspring developed by asexual generation in its manifold phrases.
If we now turn to p. 357, we find the conclusion arrived at, as it would appear, on the most satisfactory evidence, that “sexual and asexual reproduction are not seen to differ essentially; and . . . that asexual reproduction, the power of regrowth, and development are all parts of one and the same great law.” Does it not then follow, quite reasonably and necessarily, that all offspring, however generated, is in one sense part of the individuality of its parent or parents. The question, therefore, turns upon “in what sense” this may be said to be the case? To which I would venture to reply, “In the same sense as the parent plant (which is but the representative of the outside matter which it has assimilated during growth, and of its own powers of development) is the same individual that it was when it was itself an offset, or a cow the same individual that it was when it was a calf—but no otherwise.”
Not much difficulty will be felt about supposing the offset of a plant, to be imbued with the memory of the past history of the plant of which it is an offset. It is part of the plant itself; and will know whatever the plant knows. Why, then, should there be more difficulty in supposing the offspring of the highest mammals, to remember in a profound but unselfconscious way, the anterior history of the creatures of which they too have been part and parcel?
Personal identity, then, is much like species itself. It is now, thanks to Mr. Darwin, generally held that species blend or have blended into one another; so that any possibility of arrangement and apparent subdivision into definite groups, is due to the suppression by death both of individuals and whole genera, which, had they been now existing, would have linked all living beings by a series of gradations so subtle that little classification could have been attempted. How it is that the one great personality of life as a whole, should have split itself up into so many centres of thought and action, each one of which is wholly, or at any rate nearly, unconscious of its connection with the other members, instead of having grown up into a huge polyp, or as it were coral reef or compound animal over the whole world, which should be conscious but of its own one single existence; how it is that the daily waste of this creature should be carried on by the conscious death of its individual members, instead of by the unconscious waste of tissue which goes on in the bodies of each individual (if indeed the tissue which we waste daily in our own bodies is so unconscious of its birth and death as we suppose); how, again, that the daily repair of this huge creature life should have become decentralised, and be carried on by conscious reproduction on the part of its component items, instead of by the unconscious nutrition of the whole from a single centre, as the nutrition of our own bodies would appear (though perhaps falsely) to be carried on; these are matters upon which I dare not speculate here, but on which some reflections may follow in subsequent chapters.