that another and higher form of consciousness than the one we know might come into existence? What assurance have we that animal, human life is the highest development possible? Are there any indications that a higher form is likely to supersede human development? Yes, answers this ancient philosopher of Erewhon, machines show unmistakable signs of superseding man. True, they have little consciousness as yet, but remember that the mollusc had little at one time. And note the extent to which men are already the slaves of machines. If the latter were all destroyed, the human race would die in six weeks. And then consider what a short time, comparatively, it has taken machines to gain this ascendency. Animal and plant life has been in this world for, say, twenty million years; machines as we know them have been born about five minutes ago, relatively. But, the objectors say, the machines require men to tend them, to feed them. True, comes the answer, but whereas a generation ago plows required horses and men to give them food, that is, energy, now we see them feeding themselves. But at least machines can never reproduce themselves. Perhaps not in the ordinary sense; and yet we see machines making other machines. Yes, but still man is always the agent, the director in such activities. Very well, answers the philosopher, wherein does man's rôle in this respect differ from that of the bees which act as intermediaries between certain kinds of flowers and are absolutely necessary to their reproduction? In the end the philosopher's argument carries the day, with the result observed in the early part of the book: machines, originally made by man to satisfy certain desires, had been destroyed, all but the very simplest, in order to prevent their almost certain ascendency when time had given them an adequate chance for development.

Before tracing the development of Butler's theory of Life and Habit from this beginning, let us first note some of the preliminary observations he makes.

Something we do

What is the ordinary meaning of Habit? easily because we have often done it before. A child walks because in the first place he wants to walk and has formed the habit by frequent repetition. Generally we do best what we do unconsciously. An accomplished pianist who by an exercise of will has

mastered a difficult piece of music may play anywhere from one thousand to two thousand notes in one minute of a performance. He may be so unconscious of what he does that he can talk about an entirely different subject during the performance. Yet he is remembering all the time. In other words, memory, conscious or unconscious, is involved in an habitual action. The more unconsciously we perform, the better the performance. Ask the pianist to repeat any particular bar he has just played, and he will probably say that he can't remember, and will have to go back and play the phrase leading into the particular passage. In other words, as soon as he becomes conscious of his acts, he is embarrassed. This phenomenon is illustrated in a thousand ways, but take for instance the case of the centipede which had never thought of the complex manipulation of his hundred feet:

The centipede was happy quite

Until the frog, for fun,

Said, "Pray, which leg comes after which?"

This wrought him up to such a pitch

He lay distracted in the ditch,

Considering how to run.

Memory and habit are thus inter-related phenomena. Furthermore, heredity, says Butler, exhibits all the characteristics of memory. It is, in fact, a mode of memory, and an extension of memory which links one generation with another. And here we must pause to trace the development of the theme of Life and Habit.

In "The Book of the Machines" Butler had looked upon machines as extra limbs which we have manufactured for ourselves because we need them, and which we can carry about with us or leave at home, as we wish. We want, for instance, to go a long journey in a short time and we take our extra feet in the form of a train or automobile and travel fifty miles in one hour. In our day of airplanes the winged feet of Mercury are no longer a mere symbol; they are a metaphor.

Having worked this idea as far as it would go, he next considers limbs as machines which also we have made for ourselves. But we do not remember having made them, and if we were now asked to grow other limbs or to extend those we have, we should be at a

stand. We know how to make machines, because we have past experience to draw from. How can we know how to make limbs without having had experience? If we have not had such experience, our ancestors have, and can we not act upon the experience inherited from our forebears? Not unless we and our ancestors are one and the same. Are we and our ancestors the same? The answer involves the question of personal identity. The man of eighty is generally conceded to be the same person as the baby he was when one day old. But there is less difference between the babe to be born in one day and the child of one day old than there is between the baby and the octogenarian. It is, therefore, reasonable to conclude that the embryo and the man of eighty are one and the same. But the embryo is continuous with the ovum from which it has developed; therefore the embryo and the parents are continuous; therefore the parents and the child of eighty years are identical. Hence, using the same mode of reasoning, we can conclude that man and his ancestors are identical. Similarly we can argue for identity between any man living with the primordial cell from which he developed. We can, therefore, fairly say that we can act on the experience of our ancestors back to the very beginnings of life.

Consider any stage of development; say, the fish stage. The fish by some means (natural selection perhaps one of them), after a succession of generations extending through, say, 100,000 years, has learned how to grow fins, and the growing of fins by the fish is a habit so firmly established that the fish must grow fins, willynilly; and he does it without any conscious act of memory as to the method of procedure of his ancestors. The memory lies latent until aroused by the recurrence of familiar associations, when it acts as it were mechanically; just as a pianist associates one note with another without consciously remembering the notes at all. Analogous observations can, of course, be made of all the stages from the primordial cell up to Lloyd George, Jack Dempsey or Einstein. If we represent the primordial stage by a letter and the successive stages by the same letter plus a numeral, the numbers would represent the variations, while the letter would stand for the essential identity of each stage with all the rest. A1000 might be said to represent the fish stage, A7000 the ape stage, and

A, man. Note that with all the variations man is identical with, or at least identified with, all the forms through which he has passed, back to the primordial cell.

Every man passes through all these stages of development while in the embryo-the simple cell, the fish, the tadpole, the ape, man. He reproduces them unconsciously because of long habit, invincible habit, through memory of what his ancestors have done. After birth, that is, on reaching the human stage, he begins an existence of which he has had much less experience than of the stages preceding. Some functions which he has in common. with all the lower animals, such as breathing, digesting, blood pumping, he performs without effort. Other habits, such as talking and walking he does not do so easily; in fact he usually requires a year or two to be able to do them at all, and several years to do them perfectly. The reason of this phenomenon is that these are distinctly human qualities which he has recently acquired, say within the past fifty thousand years, whereas he has been digesting and breathing for, say, twenty or even fifty million years. Of most of the activities which, as a man, he is forced to engage in, such as providing food and shelter, he has still less knowledge, having been performing them, say, for only twenty thousand years. Frequently he finds himself in circumstances of which he has had so little experience for instance, when he has to provide for himself in times of famine-that he is completely at a loss and sometimes even dies before he becomes accustomed to the strangeness of the environment. Especially is this the case as he advances from middle life to old age. Of this period he has less and less experience since most of the race have been procreated before middle life has been reached by the parents. A time finally comes when he has no memory, no ancestral experience to fall back upon, and he dies of old age. But here is the nonscientific, whimsical, yet convincing way in which Butler himself sums up man's achievement through, and dependence upon, memory:

Let An stand for a man. He begins as the primordial cell-being verily nothing but the primordial cell which goes on splitting itself up for ever, but gaining continually in experience. Put him in the same position as he was in before and he will do as he did before. First he will do his tadpole by rote, so

to speak, on his head, from long practice; then he does his fish trick; then he grows arms and legs, all unconsciously from the inveteracy of the habit, till he comes to doing his man, and this lesson he has not yet learnt so thoroughly. Some part of it, as the breathing and oxidization business, he is well up to, inasmuch as they form part of previous rôles, but the teeth and hair, the upright position, the power of speech, though all tolerably familiar, give him more trouble for he is very stupid—a regular dunce in fact. Then comes his newer and more complex environment, and this puzzles him-arrests his attention— whereon consciousness springs into existence, as a spark from a horse's hoof.— (Note Books.)

Butler's unconventional style, his plain common-sense way of putting forward ideas, his sly humor, have frequently misled critics to infer that he does not intend to be taken seriously. Such an idea, however, is far from the truth. This apparent trifling with an important scientific subject has a very serious bearing. What, then, did Butler claim for his theory?

He claimed in general that it was more logical than the socalled scientific explanations of the phenomena connected with the doctrine of Evolution; that it co-related, as other theories did not, a great body of the observed phenomena of life. As this is too wide a proposition to discuss adequately, let me, following Butler, enumerate a few of the phenomena which, he claimed, were better explained by his theory than by any other.

(1) It is observed that most hybrids are sterile. The mule, for example, cannot reproduce its kind. This phenomenon is what might be expected if Butler's theory is sound. How, says Butler, if heredity be an affair of memory, can the germ of a mule be expected to build up another mule on the strength of but two mule memories? Previously to the mule-cell which is expected to develop into an embryo mule, there is the memory of only two mules, the would-be father and mother, and this is not enough experience to proceed upon. Hence memory is at fault and the germ does not develop. Similarly, in hybrids generally there is a fault in the chain of memory; and to this cause the usual sterility of hybrids must be referred.

(2) Reversion to an earlier ancestral type is one of the commonest observations in natural history. Into a flock of pure white pigeons, for example, there now and again comes a rock pigeon. On the bush of the cultivated garden rose, there occa