Einstein, the searcher

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.

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.