CHAPTER XI

EINSTEIN'S LIFE AND PERSONALITY

WE know from the biographies of great thinkers that they seldom personify the character of a dramatic ideal. They are not heroes of fiction who pass through complex experiences and struggle with mysterious problems of existence that may unduly excite the imagination of observers. Whoever follows their development remarks in the majority of cases the predominance of the inner life, the course of which is discoverable only by study of their works, no clue being given in the confusion of ordinary exterior manifestations. An eminent man of thought, whose energies are concentrated on mental effort, rarely finds time to present in addition an interesting figure in the epic sense. The poet who moulds his forms from life finds little scope in him as a model, and only in exceptional cases has he succeeded in idealizing the savant in a work of art.

It would be a fruitless undertaking to treat Einstein's life as one of these exceptional cases. It is possible to trace the various phases of his development, yet neither the writer nor the reader must disguise from himself the fact that such outlines give only the external picture of the man and chronological events of importance. Nevertheless, a book of which he forms the theme cannot pass over the task of giving his _curriculum vitæ_. And if it should partly appear aphoristic and disjointed, it must be borne in mind that this account originated from conversations and scraps of conversation that touched on various episodes of his life, according as they had a bearing on the subject under discussion.

The story of Einstein's life begins at Ulm, the town which possesses the highest building in Germany. Gladly would I stand on the belfry of the Ulm Cathedral in order to obtain a general survey of Einstein's youth. But the view discloses nothing beyond the bare fact that he was born there in March 1879. The detail which has already been mentioned above, namely, that it was something physical that first arrested the child's attention, remains to be noted. His father once showed the infant, as he lay in his cot, a compass, simply with the idea of amusing him--and in the five-year-old boy the swinging metal needle awakened for the first time the greatest wonderment about unknown cohesive forces, a wonderment that was an index of the research spirit that was still lying dormant in his consciousness. The remembrance of this psychical event has a significant meaning for the Einstein of to-day. In him all the impressions of early childhood seem to be still vivid, the more so as all other physical occurrences, such as the falling of an unsupported body, left no impression on him. His attention was fixed on the compass, and the compass alone. This instrument addressed him in oracular language, indicating to him an electromagnetic field that was in later years to serve him as a domain for fruitful research.

His father, who had a sunny, optimistic temperament, and was inclined towards a somewhat aimless existence, at this time moved the seat of the family from Ulm to Munich. They here lived in a modest house in an idyllic situation and surrounded by a garden. The pure joy of Nature entered into the heart of the boy, a feeling that is usually foreign to the youthful inhabitants of cities of dead stone. Nature whispered song to him, and at the coming of the spring-tide infused his being with joy, to which he resigned himself in happy contemplation. A religious undercurrent of feeling made itself manifest in him, and it was strengthened by the elementary stimulus of the scented air, of buds and bushes, to which was added the educational influence of home and school. This was not because ritualistic habits reigned in the family. But it had so happened that he learned simultaneously the teachings of the Jewish as well as the Catholic Church; and he had extracted from them that which was common and conducive to a strengthening of faith, and not what conflicted.

Youthful impetuosity, which in boys of a similar age usually expresses itself in rash enterprises and loose tricks, did not appear in him. His spirit was adjusted to contemplation, and an inborn fatalism, diffused with a super-sensuous element appertaining to dreams, restrained him from responding to external impulses. He reacted slowly and hesitatingly, and he interpreted what his senses offered him and all the little experiences of early days in terms of a reverence reflected from within. Words did not easily rise from his lips, and measured by the ordinary scale of rapidity of learning and readiness in answering questions, he would scarcely have been judged to possess unusual gifts. As an infant he had started to talk so late that his parents had been in some alarm about the possibility of an abnormality in their child. At the age of eight or nine years he presented the picture of a shy, hesitating, unsociable boy, who passed on his way alone, dreaming to himself, and going to and from school without feeling the need of a comrade. He was nicknamed "Biedermaier," because he was looked on as having a pathological love for truth and justice. What at that time seemed to be pathological, to-day appears as a deeply rooted and irrepressible natural instinct. Whoever has got to know Einstein as a man and as a scientist knows that this failing of his boyhood was but the forerunner of a very healthy outlook.

Signs of his love for music showed themselves very early. He thought out little songs in praise of God, and used to sing them to himself in the pious seclusion that he preserved even with respect to his parents. Music, Nature, and God became intermingled in him in a complex of feeling, a moral unity, the traces of which never vanished, although later the religious factor became extended to a general ethical outlook on the world. At first he clung to a faith free from all doubt, as had been infused into him by the private Jewish instruction at home and the Catholic instruction at school. He read his Bible without feeling the need of examining it critically; he accepted it as a simple moral teaching and found himself little inclined to confirm it by rational arguments inasmuch as his reading extended very little beyond its circle.

Painful inner conflicts were not wanting. Jewish children formed a small minority in the school, and it was here that the boy Albert felt the first ripples of the anti-semitic wave that, sweeping on from without, was threatening to overwhelm master and pupil alike. For the first time he felt himself oppressed by something that was not in harmony with his simple temperament. His modesty made him a prey to injustice, and in defending himself his originally gentle and restrained nature gained a certain independence and individuality.

If one may speak of achievements at all in a preparatory school, those of Albert were of the average modest level. He was careful as a pupil, generally satisfied requirements, but in no way betrayed special talents: indeed, so much the less, as he showed himself to be possessed of a very uncertain memory for words. The methodic plan of the elementary school that he attended to his tenth year was, however, not other than the usual scheme mapped out by drill-masters; it made up for what was lacking in an understanding of the pupils by applying drastic strictness. The beautiful sentence of Jean Paul: "Memory is the only paradise from which we cannot be banished," finds no echo in Einstein's school memories, of which he has often spoken to me without a shadow of regret for a lost paradise. He told me with bitter sarcasm that his teachers had the character of sergeants--those later in the _gymnasium_ (secondary school) were of the nature of lieutenants. Both terms are used in the pre-armistice sense, and his words were directed against the self-opinionated tone and customs of these garrison-schools of earlier days.

The next stage of his development was a course of study at the Luitpold-Gymnasium in Munich, which placed him in the second class. In Einstein's retrospect of these days more friendly recollections present themselves, connected, however, only with particular persons, and not breathing praise in general; on the contrary, from his account, it is clear that although he conceived affection for individual teachers, he felt the tone of the institute as a whole to be rough. As we know, many things have been changed in these schools since then, following on a revulsion from the convict atmosphere that used to characterize them, and which meant suffering enough for the pupils. The result was that the schoolboy Einstein developed a contempt for human institutions and assigned little value to the subjects of study which he was obliged to absorb in schematic form without the application of his own mental energy. This gloomy picture is relieved at points by the presence of several teachers, above all, one called Ruëss, who took pains in exposing the beauty of classical antiquity to the fourteen-year-old boy. We learn elsewhere that Einstein at present admits the humanistic ideal for the school of the future only under very restricted limitations. But when he thinks of this teacher and his influence, a warm appreciation of classical study vibrates in his words, occasionally rising, indeed, to an unbounded enthusiasm for the treasures of Greek history and literature. His instruction was not restricted to the acquisition of a perspective of the antique. Under the direction of the same teacher, he was introduced into the poetic world of his native country, and learned the magic of Goethe in his "Hermann and Dorothea"; this poem, as he confesses, was explained to him in a really model manner. Thus there were some oases in the desert of schematic teaching: they served as refreshing halts for the spirit of the eager young searcher after knowledge.

We must go back one or two years to note a weighty experience, which occurred when he made his first acquaintance with elementary mathematics; this subject presented itself to him with the intensity of a revelation. It did not happen in the ordinary course of school-work, but was due to a sort of wizard-like inquiring inner spirit that plied him with questions and that gave him inward thrills of joy when he found a sharp-witted solution. From the very beginning Albert proved himself to be a good solver of problems, even before he achieved an arithmetical virtuosity, and before he knew the technique of equations. He helped himself by means of little tricks, experimented roundabout inventions, and was happily excited when they led to the goal. One day he asked his uncle, Jacob Einstein, an engineer who lived in Munich, a certain question. He had heard the word "algebra" and surmised that his uncle would be able to explain the term to him. Uncle Jacob answered: "Algebra is the calculus of indolence. If you do not know a certain quantity, you call it _x_ and treat it as if you do know it, then you put down the relationship given, and determine this _x_ later." That was quite sufficient. The boy received a book containing algebraic problems that he solved all alone in accordance with this not exhaustive but expedient direction. On another occasion Uncle Jacob told him the enunciation of Pythagoras' theorem without giving him a proof. His nephew understood the relationship involved, and felt that it had to be founded on some reasoning. Again he set about all alone to furnish what was wanting. This was, however, not a case for the "calculus of indolence" with an _x_ that was to be determined. Here it was a question of developing a facility for geometric argument, such as very few possess at such an early stage of development. The boy plunged himself for three weeks into the task of solving the theorem, using all his power of thought. He came to consider similarity of triangles (by dropping a perpendicular from one vertex of the right-angled triangle on to the hypotenuse), and was thus led to a proof for which he had so ardently longed! And although it concerned only a very old well-known theorem, he experienced the first joy of the discoverer. The proof that he had found proved that the ingenuity of the worrying young mind was awakening.

A new world was opened for him when he made the acquaintance of A. Bernstein's comprehensive popular books on scientific subjects. This work is looked on nowadays as being somewhat antiquated and, in the eyes of many a professional scientist, has sunk to the level of a pseudo-scientific "shocker"; even when Einstein as a boy made explorations in it, there were signs of rust and decay in the work, for it originated in the fifties of the previous century and, in point of subject-matter, had long been transcended. Yet it could be read then--and even now--as a story containing thousands of interspersed physical, astronomical, and chemical wonders, and for the boy Einstein it came to be a true book of Nature, which presented to his mind, greedy for knowledge, as much as it did to his imagination.

Other vistas were opened up to him by Büchner's _Kraft und Stoff_ (_Force and Substance_), a book the cheapness of which he could not yet discern, but which called up wonder in him without rousing his criticism. In addition, his attention was chiefly occupied by a handbook of elementary planimetry, containing an abundance of geometrical exercises, which he fearlessly attacked and within a very short time solved almost in their entirety. His delight grew when he ventured into the difficulties of analytical geometry and infinitesimal calculus quite apart from the curriculum of his school-work. Lübsen's textbook had fallen into his hands, and these directions sufficed for his audacious spirit. Whereas many of his school companions were still standing undecidedly before the pools of theorems of congruence and repeating decimals, he was already disporting himself freely in the ocean of infinitesimals. His work did not remain concealed, and gained appreciation. His mathematical teacher declared that the fifteen-year-old boy was ripe for university study.

Yet he was not to find a way into the open by matriculating very early, but through an event that unexpectedly threw him into new surroundings of life. In 1894 his parents transferred their abode to Italy. The chronicler has nothing to report of pangs of separation in Albert when he left Bavarian soil. He was glad to get away from the drill academy, Luitpold, and, as an inhabitant of Milan, he enjoyed the change in his existence, and was not encumbered by attacks of home-sickness. All in all, he had felt himself in an unhappy position under school compulsion in Munich, in spite of the mathematical delights he had provided for himself, and in spite of the rapturous moments that musical revelations had created for him since his twelfth year. Defiance and distrust against outside influences had remained active in him as forces that did not allow the happy disposition proper to his age to assert itself. But now the fetters had fallen and the pent-up joy of life burst forth as if through opened sluices. The sun and landscape of the South, Italian manners of life, art freely displayed in the market-place and on the street, realized for him dream-pictures that had appeared to him earlier during the hours of oppression. Whatever he saw, felt, and experienced lay outside the ordinary course of his life, awakened his sense for natural and human things, and set his spirit free from all bonds. There was no question of his going to school in the first six months. He enjoyed complete freedom, occupied himself with literature, and undertook extended excursions. Starting from Pavia, he wandered all alone over the Apennine to Genoa. Whilst he was being intoxicated with the sublime Alpine landscape, he came into contact with the lower stratum of the people, who aroused his deepest sympathy. The tour took him over a short stretch of the Italian Riviera, the beauties of which, as depicted by Böcklin, do not seem to have revealed themselves to him. At that time he was probably subject to a feeling of upward striving such as possessed Zarathustra.

With all their joys and inspirations the experiences in Italy remained but a short episode. Einstein resolved on a new tour, which was not without a professional purpose. He made a pilgrimage to Switzerland with the intention of studying mathematics and physics at the Zürich Polytechnical Institute. But he was not to be successful in his first effort to gain entrance. The conditions of entry required a standard in descriptive sciences and modern languages that he had not yet reached. So he turned to Aarau, where he was allowed to extend his knowledge with the help of excellent methods at the Canton school. Even it the present day Einstein talks with extreme enthusiasm of the organization of this model school that corresponds in rank approximately to a German Realgymnasium (or an English Grammar School). There was nothing to remind him of the continual manipulation of the sceptre of authority at the Luitpold school barracks; he easily obtained his leaving certificate, and now the portals of the Zürich Polytechnicum were open for him.

He himself was probably not aware that he carried a marshal's baton in his own mathematical equipment. But, in looking back, we come across astounding things. For it is a fact that even in the pupil at Aarau problems had taken root that already lay in the vanguard of research at that time. He was not yet a finder, but what he sought as a sixteen-year-old boy was already stretching into the realms of his later discoveries. We have here simply to register facts, and to abstain from making an analysis of his development, for how are we to trace out the intermediate steps, and to discover the sudden phases of thought that lead a very young Canton pupil to feel his way into a still undiscovered branch of physics? The problem that occupied him was the optics of moving bodies, or, more exactly, the emission of light from bodies that move relatively to the ether. This contains the first flash of the grandiose complex of ideas that was later to lead to a revision of our picture of the world. And if a biographer should state that the first beginnings of the doctrine of relativity occurred at that time, he would not be making an objectively false statement.

The ambitions of the youth by no means reached these flights of imagination, for whereas the latter signified the coming power of his wings, he himself set a modest goal. He wished to become a schoolmaster, and imagined that in choosing this career he was allowing his hopes to run high. This was in conformity with the esteem in which he held the status of teachers. In the Zürich Technical School there is a section equipped as a department for preparing teachers, and in this Einstein studied from the age of seventeen to the age of twenty-one, perfectly satisfied with the thought of sitting, not on the pupil's bench, but at the master's desk, and of exercising a beneficial if limited influence as a preceptor of the young.

He was still under the sway of the feeling that he was not sufficiently experienced in life and that he dare not venture out into the light for existence in the great turmoil of the world. He saw in this struggle, which pitted man against man, led to exhibitions of violence, and aroused ambition for glittering unrealities, cause only for disgust and alienation. The prospect of personal success did not lure him to try force against force. Thus, for the time being, it was his ideal to lead a very modest existence. From various quarters he had been given hopes of a position as assistant to some professor of physics or mathematics. But for unknown reasons he was everywhere refused. These apparently obscure grounds, it must be said with regret, become clearer when we bear in mind his confession of faith. Nor did his hopes of teaching at a gymnasium seem near fulfilment, as certain conditions of birth raised obstacles. In the first place, he was not a Swiss; in fact, since his stay in Milan he was without a nationality at all in the bureaucratic sense, and then he had no personal connexions, without which, at least at that time, there was no chance of progress even for a talented person. Yet the young student who was entirely without protection of any sort had to overcome the cares and satisfy the needs of daily life. He could not rely on material help from his parents, who themselves lived in restricted circumstances, and thus we find him a little later in Schaffhausen and Bern, where he earned a small pittance as a private tutor.

He found consolation in the fact that he preserved a certain independence, which meant the more to him as his instinct for freedom led him to discover the essential things in himself. Thus, earlier, too, during his studies at Zürich he had carried on his work in theoretical physics at home, almost entirely apart from the lectures at the Polytechnic, plunging himself into the writings of Kirchhoff, Helmholtz, Hertz, Boltzmann, and Drude. Disregarding chronological order, we must here mention that he found a partner in these studies who was working in a similar direction, a Southern Slavonic student, whom he married in the year 1903. This union was dissolved after a number of years. Later he found the ideal of domestic happiness at the side of a woman whose grace is matched by her intelligence, Else Einstein, his cousin, whom he married in Berlin.

In 1901, after living in Switzerland for five years, he acquired the citizenship of Zürich, and this at last gave him the opportunity of rising above material cares. His University friend, Marcel Grossmann, lent him a helping hand by recommending him to the Swiss Patent Office, the director of which was his personal friend. Einstein occupied himself here from 1902 to 1905 as a technical expert, that is, as an examiner of applications for patents, and this position gave him the chance of moving about in absolute freedom in the realms of technical science. Whoever has a strong predilection for discovery will perhaps feel estranged to find Einstein so long in the sphere of "invention," but, as Einstein himself emphasizes very strongly, both regions make great demands on clearly defined and accurate thought. He recognizes a definite relationship between the knowledge that he gained at the Patent Office and the theoretical results that appeared at the same time as products of intensive thought.

In 1905, in the midst of his work, the storm broke loose in him with the suddenness of a hurricane. In quick succession his mind disburdened itself of the abundance of ideas that had stored themselves up in the work of the preceding years, and these ideas signify more to us than a definite stage in the development of an individual. What physicists have come to regard as an elaboration of the heritage of Galilei and Newton had matured in him. We merely record the title of dissertations, which appeared in 1905 in the _Annalen der Physik_: "Concerning a Heuristic Standpoint towards the Production and Transformation of Light"--"Concerning the Inertia of Energy"--"The Law of Brownian Movement."--Then the most important contribution: "The Electrodynamics of Moving Bodies," that contained the revolutionary ideas underlying the special theory of relativity. To these is to be added a dissertation for his doctorate in the same year: "A New Determination of Molecular Dimensions."

In all, these represent a life-work that belongs to the history of science. It was certainly some considerable time before his work began its triumphal march in the sight of the world, and it may be added that treasures were hidden in these disquisitions that were not understood till long years afterwards. Yet the youthful discoverer was not passed over without signs of friendly appreciation. He received a letter, couched in very warm terms, from the celebrated physicist, Max Planck, who was a complete stranger to him at that time; it spoke in glowing words of his essay, "The Electrodynamics of Moving Bodies." This letter was the first diploma, the forerunner of all the honours that later swept over him like a tidal wave.

It was his intention to obtain a tutorial position at the University. An appointment to Bern was at first again hindered by certain obstacles which he would probably have overcome if he had applied himself energetically to attaining his goal. He finally received his appointment, but exercised his duties for only a very short time, as Zürich now opened her arms to him. In 1909 he accepted the position of Professor extraordinarius there for theoretical physics, and soon assembled a grateful audience about himself. Nevertheless, during the earlier stages of his professorship he found it difficult to suppress a longing for the quiet, unexcited life of his patent-office work, in which he seemed to have had a still greater degree of independence. In 1911 he accepted a new appointment as Professor Ordinarius to Prague, which offered him more favourable emoluments as an inducement. In the autumn of 1912 he returned to Zürich as a Professor at the Polytechnic, and in the early part of 1914 he was drawn into the strong magnetic field of the northern capital; he arrived at the Spree, and has, since then, lived among us. He is now a Swiss by nationality, a world citizen by conviction, and, professionally, a member of the Berlin Academy and attached in a lecturing capacity to the University. Here he perfected his works on relativity, ending in the superlative elaboration of the theory of gravitation, the beginnings of which stretch back to the year 1907. He had spent eight years in a concentrated effort of severe thought to bring it to completion, and perhaps centuries will be necessary before the world will gain a complete perspective of all the consequences of his theory.

For the theory asks us to brush aside habits of thought that have claimed an hereditary position in pre-eminent minds. One of the foremost physicists, Henri Poincaré, had confessed as late as 1910 that it caused him the greatest effort to find his way into Einstein's new mechanics. Another whole year passed before he gave up his last doubts. Then he passed with flying colours into Einstein's camp, and recommended Einstein's appointment to the Professorship at Zürich, in conjunction with the discoverer of radium, Madame Curie, in an exuberant letter which may add its note of appreciation here:

"Herr Einstein," so wrote the great Poincaré, "is one of the most original minds that I have ever met. In spite of his youth he already occupies a very honourable position among the foremost savants of his time. What we marvel at in him, above all, is the ease with which he adjusts himself to new conceptions and draws all possible deductions from them. He does not cling tightly to classical principles, but sees all conceivable possibilities when he is confronted with a physical problem. In his mind this becomes transformed into an anticipation of new phenomena that may some day be verified in actual experience.... The future will give more and more proofs of the merits of Herr Einstein, and the University that succeeds in attaching him to itself may be certain that it will derive honour from its connexion with the young master."

We may be tempted to look back and ask whether the criteria that Wilhelm Ostwald once set up as a test of great men are verified in Einstein's case. He has certainly not broken the first and most general rule, the principle of "early maturity." This showed itself clearly when his impulse towards mathematical knowledge and discovery asserted itself, and when he penetrated far into the future with his optical problems. The history of science and of art may offer more striking examples in this connexion, but at any rate in Einstein's case the indications are sufficient to serve as a confirmation of the rule. On the other hand, the second test of Ostwald seems to be valid only conditionally when applied to Einstein. For Ostwald takes up arms against a "gradual intensification" of ability, and proclaims it as an almost universal rule that the exceptional achievement is the privilege of quite young persons: "what he achieves later is seldom as impressive as his first brilliant achievement." Thus, in Einstein's case, the exception is evident. For if we fix on only two chief discoveries, passing over many others, there is no doubt that the second (the theory of gravitation) surpasses the first (special relativity) in both range and significance. Indeed, we cannot escape from the idea of a "gradual intensification," for the second discovery could come about only as a result of the first. Moreover, it is not yet night, and there is nothing to refute the assumption that there will be a further progression.

Furthermore, Ostwald takes into consideration the tempo of the intellectual pulse of inspiration to divide the main types of great men into a classical and a romantic category: this classification cannot, however, be applied to Einstein. He is decidedly classical, in so far as his work seems calculated to serve later generations as a classical foundation for all mechanical investigations of the macrocosm of the heavens and the microcosm of atoms. On the other hand, his versatility, the mobility and resource of his highly imaginative mind, stamp him as a romantic spirit. His delight in teaching would also assign him to this category, for in the case of many classical spirits there is a decided aversion to imparting instruction. So that, although we might well be able to speak of a synthesis of these two forms, it seems better to estimate Einstein, not in the light of a ready scheme, but rather as a type of which he is the unique representative.

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Just as the external contour of his life is on the whole regular and unbroken, so also his inner life is attuned to simplicity. Nowhere, it might almost be said, do we observe a break, a spasmodic turn, or a sudden intensification. Although he has grasped and suggested so many problems, he himself presents no psychological riddle, and we meet with no singularities in analysing his personality. It has already been remarked several times that Art plays a part in his life. What I learned from him himself about his affection for music coincides exactly with what observation clearly discloses. The expression of his countenance when he is listening to music is a sufficient indication of the resonances induced in him. He is confessedly a classicist, and a sincere devotee of the revelations of Bach, Haydn, and Mozart. What fascinates and enraptures him above all is that which is directed inwards, which is contemplative and erected on a religious basis. The simple masterful flow in musical development and invention is all-important for him. The architectonic structure that we marvel at in Bach, the Gothic tendency towards heavenly heights, perhaps calls up in him sensations that emanate from his hidden wealth of constructive mathematical ideas. It seems to me that this possibility is not unworthy of remark. It suggests a reason for the fact that he gives himself up only unwillingly to the nervous strain of drama directed at emotional upheaval. He does not gladly overstep the boundary that separates the simple from the psychologically subtle, and whenever his desire to understand art requires him to venture beyond it, his appreciation is not accompanied by genuine pleasure. His subjectivity does not fix this boundary in accordance with the ordinary rules of concert æsthetics, which are actually not rules at all, but only changeable valuations and crystallizations of the feelings of certain groups of people. He gives himself up quietly and freely to what is presented, but makes no special effort to assimilate experiences to which his being does not spontaneously react. There would be no meaning in seeking to mark off the limits of his receptivity in accordance with this, and to tell him that it is too limited, and that it should be enlarged, and that he should not regard as an opinionated exaggeration what appears to others to be a deep and mighty revelation, or seems to be possessed of divine sweetness. He would be able to point out that even in the case of masters of the musical art a change of faith was not a rare occurrence, and that they learned anew, or rejected what they once idolized, and very often found no permanent haven in their own faith. Whoever, like Einstein, gives himself up to the simply contemplative, and feels no impulse towards sensationalism, is spared the task of learning afresh, and finds still one world left for him even if many other worlds are inaccessible. To mention only the main features, then, neither Beethoven as a composer of symphonies, nor Richard Wagner, denote the pinnacles of music for him; he could live without the Ninth Symphony, but not without Beethoven's ensemble music. The number of composers and compositions which are not a necessity of life for him is very considerable. It includes the majority of romanticists, the erotically inclined school of Chopin and Schumann, which revels in sensation, and, as already mentioned, the neo-German dramatic composers. He has much objective admiration for them, yet he does not conceal the fact that he also feels lively opposition in the gamut of his sensations. He regards the properly modern productions as interesting phenomena, and has various degrees of disapproval for them, extending to complete aversion. It costs him an effort to hear an opera of Wagner, and when he has done so, he returns home bearing with him the _leitmotiv_ of Meister Eckhard: "The lust of creatures is intermingled with bitterness." In general he seems to take up approximately the point of view of Rossini. Wagner gives him wonderful moments, followed, however, by periods of acute emotional distress. I need hardly add that I myself, who confess to being an ultra-Wagnerite, never strove in my conversations with Einstein to make my opinion prevail against his. For I am deeply convinced that in this matter there is no question of right and wrong, and that every musical valuation represents no more than an accidental judgment dependent on one's own nature, entirely egocentric and thus objectively of no account.

Einstein also occupies himself in an active sense with music, and has developed into a very fair violinist, without claiming higher degrees of achievement. Among other things I once heard him play the violin part of a Brahms Sonata, and his performance approached concert standard. He draws a beautiful tone, infuses expression into his rendering, and knows how to overcome the technical difficulties. Among the supreme artists of his instrument who have exerted a personal influence on him, Joachim assumes the first place. Einstein still speaks with great enthusiasm of Joachim's performance of Beethoven's Tenth Sonata and of Bach's Chaconne. He himself plays the latter piece, for which the purity and accuracy of his double and multiple stopping fits him. Whoever chooses the right moment--this good fortune has not yet befallen me--may overhear Einstein at his pianistic studies. As he confessed to me, improvisation on the piano is a necessity of his life. Every journey that takes him away from the instrument for some time excites a home-sickness for his piano, and when he returns he longingly caresses the keys to ease himself of the burden of the tone experiences that have mounted up in him, giving them utterance in improvisations.

The regular run of concerts in which displays of bravura play an important part finds little favour with him; above all, he is not a worshipper of the orchestral conductor, whom he regards only as an interpreter and not as a virtuoso on the orchestral instrument. He expressed this idea in unmistakable words: "The conductor should keep himself in the background." I believe that his dearest wish would be to breathe in the tones without a personal or material medium, merely out of the air or out of space. Furthermore, I believe that there is an unfathomable connexion between his musical instinct and his nature as a research scientist. For the ear, as we know from Mach, is the true organ that enables us to experience space, and thus things may occur within the ear of the investigator of space that may have a different significance from that of music which is representable in tones. I strongly doubt whether traces of compositional form occur in Einstein's tone-monologues, but perhaps they contain examples of an art for which the æsthetics of a distant future may find a name.

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With regard to higher literature, and indeed all writings not connected with science, Einstein has little to say. He himself rarely directs conversation on to this topic, and still less rarely does he give vent to an enthusiastic outburst that betrays warm interest. He restricts himself to making short, aphoristic comments, and now and then allows his listener to gather that he can easily imagine an existence without literature. The number of accepted novels, tales, and poetic works which he has not read is legion, and all the pretentiously artistic, historical, and critical writings that are added to them have attracted only a very momentary interest from him.

I have never seen him attracted in any way by the promising aspect of some new book intended for diversion. If such a one happens to get into his hands, he merely places it among the others. At times I was constrained to think of Caliph Omar's words: "If the book contains what is already in the Koran, it is unnecessary; if it contains something else, it is harmful." It is harmful at least in the sense that it robs us of time that may be better spent in another way. I am purposely exaggerating here to make it quite clear that Einstein finds full satisfaction in a narrow circle of literature, and that he experiences no loss if numerous new works pass by and escape his notice.

Nevertheless, he speaks with reverence of a series of authors, to whom he owes enrichment: among them are the classical writers, who naturally occupy the highest position, with certain exceptions, which he equally naturally wishes to be taken as a personal opinion and not in the sense of a critical valuation. With him the difference reveals itself in the intonation from which we may read a greater or lesser measure of affection. When he says "Shakespeare," the eternal greatness seems to be inherent in the actual sound of the name. When he says "Goethe," we notice a slight undertone of dissonance, which may be interpreted without difficulty. He admires him with the pathos of distance, but no warmth glows through this pathos.

I had ventured to deduce from my knowledge of his nature the men and the works which, in my opinion, should awaken strong echoes in him. A fairly clearly defined line leads to the true path. Outside of any systematic series, I may mention Dostojewski, Cervantes, Homer, Strindberg, Gottfried Keller in the positive sense, Emile Zola and Ibsen in the negative sense. Taken as a whole, this prognostication does not disagree seriously with his own statement, excepting that he lays still greater emphasis on Don Quixote and the Brothers Karamasoff than I had surmised. He expressed himself with reserve about Voltaire. He has no belief in Voltaire's poetic qualities, and sees in him only a subtle-minded and amusing writer. Perhaps if Einstein were to devote himself a little more intensively to Voltaire and Zola, he would assign a higher value to these related spirits. But there is little hope of this occurring, as the wide range of Voltaire's works tends to restrain him. Time, which the physicist Einstein has shown to be relative, has an absolute value for him when measured in hours, and whoever seeks to persuade him to read thick volumes is not likely to gain his goodwill.

Our philosophical literature is not received with acclamation by him. If some one wished to undertake the task of ascertaining Einstein's attitude towards philosophy, he would be well advised to plunge into Einstein's works rather than to ask him personally. In them the questioner would find ample hints, pointing towards a new theory of knowledge, the first indications of which are already perceptible. A great portion of philosophic doctrine will yet have to pass through the Einstein filter to be purified. He himself, it seems to me, leaves this process of filtering mostly to other thinkers, but we must not lose sight of the fact that these others derive their views of space, time, and causality from Einstein's physics. It is thus immediately evident that he does not find revelations about ultimate things in already extant literature, for the simple reason that they are not to be found there. For him famous works represent, in Kant's language, "Prolegomena to every future system of metaphysics which can claim to rank as a science." The accent is to be put on the future that has not yet become the present. He praises many, particularly Locke and Hume, but will grant finality to none, not even to the great Kant, not to mention Hegel, Schelling, and Fichte, whom he barely mentions in this connexion. To Schopenhauer and Nietzsche he assigns a high position as writers, as masters of language and moulders of impressive thoughts. He values them for their literary excellence, but denies them philosophic depth. As far as Nietzsche is concerned, whom, by the way, he regards as too glittering, Einstein certainly experiences ethical objections against this prophet of the aristocratic cult whose views are so diametrically opposed to Einstein's own opinion of the relations between man and man.

Earlier when we were talking of classical poetry he had particularly emphasized Sophocles as one who was dear to him. And this name leads us to the innermost source of Einstein as a man. "I am not here to hate with you but to love with you," is the cry of Sophocles' Antigone, and this cry is the keynote of Einstein's emotional existence. I shall not give way to the temptation to follow those who in the turmoil of the present day refer to Einstein as a political figure. That would lead to a description of policy and party arguments that lie beyond the scope of this book; so much the less am I inclined to do so as Einstein's convictions may be expressed very clearly without reference to schematic terms of a very elastic nature. An individuality such as his cannot be compressed into a party programme. And if anyone should insist on placing him among the radicals or on assigning him far to the left, I should suggest that it would be better to choose, instead of the classification right and left, that of above and below. I look up towards his idealism, whose altitude may perhaps be reached one day by the raising of our ethical standards. But not by means of paragraphs of laws. I have seldom heard him talk of such schematic recipes, but so much the more have I noted utterances which bore witness to a very intense and ever-present sympathy with every human creature. His programme, which is written not in ink but in heart's-blood, proclaims in the simplest manner the categorical imperative: Fulfil your duty to your fellow-being: offer help to every one: ward off every material oppression. "Well, then, he is a socialist," so the cry runs. If it is your pleasure to call him so, he will not deny you it. But to me this term seems to denote too narrow limits for him. I see no contradiction in applying the term, but there is no perfect congruence. If one word is necessary, I should be rather more inclined to say that he is in the widest sense a democrat of liberal trend.

For him the State is not its own aim, nor does he imagine himself to be the possessor of a panacea. "The attitude of the individual to socialism," he said, "is uncertain owing to the fact that we can never ascertain clearly how much of the iron compulsion and blind working of our economic system may be overcome by appropriate institutions." And I should like to add that such institutions would scarcely have a permanent result, but that more may be expected from the ethical example of those who have the power of renunciation. Whoever realizes the motto of Antigone, "I am here to love with you," brings us nearer the goal. All in all, our longing continually flees from the confusion of political considerations to simple morality. For Einstein this is the primary element, that which is directly evident and not open to misrepresentation. It includes sympathy, and, what is more important, joy in conjunction with others. "The best that life has to offer," he once exclaimed, "is a face glowing with happiness!"

This look is expressed on his own face when he discusses his ideals, above all the internationality of all intellectual workers and the realization of eternal peace among the nations. To him pacifism is a matter of mind as well as of heart, and he is of the opinion that the course of history so far is but the prelude to its realization. The past, with its bloodstained fingers that reach into the present, does not discourage him He points to the endless city wars of the Middle Ages in Italy, which had finally to cease in answer to the increasing feeling of solidarity. So he believes in the victory of peace, which the unified consciousness of all humanity will one day win over the demonic powers of tyranny and conquest.

The pacifistic goal seems to him to be attainable without the peculiarities of the various States being destroyed. National characteristics arising from tradition and hereditary influences do not signify in his eyes a contradiction to the internationalism that embraces the common intellectual factors of civilized peoples. Thus the desire for the preservation and care of particularities directs him to the secondary goal of Zionism. His blood asserts itself when he supports the foundation of a State in Palestine, which seems to him to be the only means of preserving the national individuality of his race without the freedom of the individual being affected.

We had left Art to talk of the State, and then returned to the former theme to touch lightly on the pictorial arts. Painting was allowed to pass with merely a fleeting remark. It plays no considerable part in Einstein's existence, and he would not suffer great grief if it were to vanish from the plane of culture, a consummation to which definite signs seems to point. I have described these signs in other writings (as in _Kunst in 1000 Jahren_), and maintain the point of view that the latest branches of painting as represented by expressionism and cubistic futurism denote, in essence, the last convulsions of a dying surface art. And even the chief representatives of former flourishing periods are beginning to fade away, and Einstein will not be the only one who will relegate this art, as compared with music, to a lower plane among the inspired arts that bring joy to humanity. He is only more frank than others when he freely confesses that he cannot convince himself that a life without the joys of pictorial art would be hopelessly impoverished. But he bows his head to sculpture, and, for him, architecture is a goddess. It is again his deeply rooted piety that asserts itself when memory recalls to him the Gothic dome with its pinnacles striving towards heaven. Goethe and Schlegel have called architecture "frozen music," and this picture is present in his mind when he sees Gothic architecture as frozen music of Bach. It is open to anyone to analyse this specific impression in another way by seeking the fundamental elements, in which the essence of the art is to provide support for a weighty structure and to overcome gravitation. For a spirit that works with mechanics and that feels within itself the pressures and tensions occurring in external nature, architecture is a kind of statics and dynamics transformed into a thing of beauty, a ravishing picture of his own science.

* * * * * * * *

Einstein has told me many a story of his travels, and these reports were characterized by an absence of definite purpose. The conception of something worth seeing in the tourists' sense does not exist for him, and he does not set out in eager pursuit of those things that are marked with two asterisks in Baedeker. The intense romanticism of Swiss scenery, that lay within such easy reach for him, has never enticed him into its magic circle, and he has nothing to do with the abysmal terrors of glaciers and the world of snow-peaks. His enthusiasm for landscape beauty conforms with the behaviour of the barometer: the greater the altitude, the lower the mercury. In simple contact with Nature he prefers the lesser mountains, the seashore, and extensive plains, whereas brilliant panoramic contours like those of the Vierwaldstetter See do not rouse him into ecstasy. It is unnecessary to remark that he does not arrange his living on the standard of the Grand Palace Hotels en route. It is nearer the truth to picture him as a vagrant who tramps along without a sense of time and without a goal, in the fairy atmosphere of a joyous wanderer who has unconsciously adopted the old rule of Philander: Walk with a steady step: make your burden small: start early in the morn, and leave home all care!

Am I to record the list of pleasures and hobbies that are foreign to him? The list would be very long, and I should arrive at my goal more quickly by setting his sporting tendencies equal to zero. I once suspected him of being given to aquatic sport, as I learned that he had taken part in several yachting excursions. But I was mistaken. He sails in the same way as he walks on his tours, without a set purpose, dreaming, and uninterested in what is regarded by members of sailing clubs as a "feat." In the negative list of his games we see even chess, that usually exerts a strong attraction on natures with a mathematical tendency. The particular types of combination offered by this game have never tempted him, and the world of chess has remained _terra incognita_ for him. He is just as little interested in every kind of collection, even that of books. I have seldom or never met a savant who attaches so little value to the personal possession of numerous and valuable books. This statement may be extended as far as saying that he experiences no pleasure at all in possession as such: he says so himself, and his whole manner of life proves it. There seems to me to be an element of resignation in his amiable hedonism, a kind of monkish asceticism. He never rids himself of the feeling that he is only paying a visit in this world.

I do not know whether Einstein considers that his life-work can be completed within the span of this visit. At any rate he makes no attempt to extract more out of the day by following a rigid programme of work than the day voluntarily offers. He does not compel himself to cover a definitely circumscribed piece of ground with chronological exactitude. There are brain-workers, especially artists, who actually never shake off the fetters of the twenty-four hours day of work inasmuch as they spin on the threads of daily effort into the nightly fabric of dreams. Einstein can make a pause, interrupt his work, or divert himself into side-channels at leisure and according to the demands of the hour, but dreams offer him no inspiration and do not waylay him with problems.

On the other hand, however, he is waylaid so much the more during the day by things and persons that make an assault on him. This starts as soon as the first post arrives, to see through which requires a special bureau. In addition to the communications of a professional or official nature there appear innumerable letters from everywhere and anywhere asking him to grant a little of his time. Whatever each individual writer has thought about the principle of relativity, all his thoughts and doubts, additions, and, above all, that which he has not been able to understand, all this is to be answered by Einstein. Has he, the child of fame, even a quarter of an hour for himself? There they wait in the hall, the painter, the photographer, the sculptor, and the interviewer; with whatever powers of persuasion and argumentative subtlety his attentive wife may seek to defend his hours of rest, some of these visitors will yet succeed in gaining the upper hand, and will produce something in oil-colours, in plaster of Paris, in black and white, in water-colours, or in print. Fame, too, demands her sacrifices, and if we talk of a hunt after fame, then Einstein is certainly not the hunter, but the hunted.

He sighs under the burden of his correspondence, not only as the recipient, but also with the sender, whose letter has to remain unanswered. Yet he is never roused to anger by the intruder on his time. If this were not so, the aphorism of Cyrus that patience is the panacea of all ills would not hold for him, and how would I myself otherwise have dared to claim so many hours of him? A sense of guilt falls on me!

But even Einstein's patience can come to an end, and this is at the point where "society" begins: I mean the congregation of persons in a salon, society entertainments to which one is invited to be seen, and so that one may claim to have been there. A solemn representation in which he is to be made the cynosure of all eyes is a torture to him. If in a very exceptional case he is compelled to participate in such a gathering, the joy of his hosts will not be entirely unmixed, for it does not require a thought-reader to recognize the longing for solitude imprinted on his countenance: "Could I but escape!"

So much the happier does he feel himself in the narrow circle of his friends, who offer what means to him much more than admiration, namely, affection, and an appreciation of his human self. He is what one wishes him to be. He is happy when he can forget the doctor profundus, and can yield himself up to the atmosphere of stimulating and unconstrained converse. He is a master in the art of listening, and is not averse to contradiction; when possible, he even emphasizes the arguments of his opponent. _Audiatur et altera pars_! This is a further manifestation of his altruistic personality, which rejoices when he extracts the true kernel from the husk of the opposing opinion. Here he also displays a characteristic which one does not usually expect to find among abstract thinkers, a sense of humour that runs through the whole gamut from a gentle smile to hearty laughter, and that is the happy source of many a striking sally. It may happen that the subject of conversation excites his anger, especially in political debates when he calls to mind militaristic or feudal misgovernment. He then becomes roused, and, as a cynical philosopher, sarcastically attacks personalities and points out the primary source of perennial hate, immediately afterwards soaring up to happy speculations of the future.

It is a matter for regret that the subjects that he has discoursed on lightly have not been fixed phonographically. Such records would form an interesting supplement to the conversations outlined in this book. It would never occur to him to set down in permanent literary form the inspiration of the moment. What he writes emanates from other regions, and is, to use his own expression, a precipitate of "thick ink." This is obvious, for what he has to proclaim as a scientist cannot be presented in a "thin" form. But many a so-called writer would have reason to congratulate himself, if so much thinly flowing matter occurred to him in writing as to Einstein in speaking.

* * * * * * * *

The record of these conversations was begun in the summer of 1919, and completed in the autumn of 1920.

INDEX

Aristoteles, 41 Arrhenius, 144

Babinet, 25 Bach, 88, 235 Bacon, 46 Baer, K. E. von, 162 Bailhaud, 144 Beethoven, 99, 234, 235 Bell, Graham, 25, 111 Béranger, 84 Bergson, 91 Bernoulli, 48 Bernstein, 225 Bessel, 32 Bohr, Niels, 57, 210 Brahe, Tycho, 94 Bruno, Giordano, 141 Büchner, 225 Bulwer, 76 Bunsen, 164 Byron, 9

Cantor, 52, 203 Cavendish, 111 Ceulen, Ludolf van, 158 Condillac, 216 Copernicus, 6, 90 Cosmati, 48 Curie, Madame, 79, 231 Cuvier, 196

Darboux, 152 Dase, 158 Descartes, 47, 133, 162 Dingeldey, 190 Dostojewski, 185, 187 Dove, 21, 155 Duhem, 105, 106 Dühring, 54, 56

Eckermann, 50, 85 Edison, 140 Euclid, 180 Euler, 98 Euripides, 85

Faraday, 39, 61, 84 Fechner, 110, 182 Fermat, 97, 190 Fizeau, 113 Flammarion, 115 Franklin, 102 Fresnel, 45

Galilei, 6, 40, 150, 179, 181 Galle, 6 Galvani, 110 Gauss, 55, 185, 186 Goethe, 13, 23, 179, 197, 212, 236 240 Grillparzer, 95 Grossmann, 229

Hansen, 134 Hebbel, 77, 86 Hegel, 42 Heine, 49 Helmholtz, 25, 26, 53, 73 Heraclitus, 23 Herschel, 84 Hertz, 60 Hooke, 41 Horace, 3 Humboldt, 49 Hume, 161 Huyghens, 56, 109, 132

Jean Paul, 86, 223 Joule, 84 Jung Stilling, 84

Kant, 35, 121, 170, 177, 179, 237 Kepler, 6, 42, 84, 176, 177 Kirchhoff, 104-107, 148, 212 Kleist, 130 Kummer, 190

Lamarck, 197 Lange, 47 Laplace, 40, 45, 140, 165 Leibniz, 26, 128 Leonardo da Vinci, 11, 50-54 Leverrier, 6, 10 Liebig, 55 Lindemann, 158 Linné, 196 Lorentz, 57, 72 Lothar Meyer, 107 Lucretius, 210

Mach, 46, 77, 108, 149, 169 Mauthner, 95 Maxwell, 39, 60 Mayer, Robert, 25, 55, 56 Melanchthon, 82 Menander, 86 Mendelejew, 107 Mezzofanti, 63 Michelangelo, 49 Michelson and Morley, 112 Mill, 45

Mithridates, 63 Montaigne, 77 Mozart, 233

Newton, 2, 6, 8, 39, 40, 43, 96 Nietzsche, 63, 217, 237 Nollet, 103

Odilon, Helene, 135 Oersted, 109 Ostwald, 83, 231, 232 Ovid, 197

Pascal, 93, 98 Pasteur, 175 Perrin, 154 Pflüger, 35 Philander, 241 Picard, 144 Planck, 57, 59, 91, 230 Poincaré, 1, 7, 112, 116, 231 Pope, 54 Priestley, 111 Psellus, 156 Pyrrhon, 92 Pythagoras, 101, 179

Quetelet, 182

Regiomantus, 52 Reis, 25 Riemann, 186 Riggenbach, 25 Ruëss, 224 Rutherford, 36, 210

Schiller, 74, 94, 170 Schlegel, 240 Schlick, Moritz, 168 Schopenhauer, 41, 237 Schwann, 175 Shakespeare, 236 Siemens, 25, 27-30 Slade, 136 Sophocles, 238 Spinoza, 84, 162 Stephenson, 25

Terence, 191 Thomas Aquinas, 165 Torricelli, 166

Vaihinger, 43, 169 Vitruvius, 101 Volta, 110, 111 Voltaire, 47, 237

Wagner, 234 Weber, 182 Weierstrass, 152 Weyl, 34 Whewell, 45 Wien, 173

Zelter, 84 Zöllner, 137