The 100 Most Influential Scientists of All Time (28 page)

Freud, still beholden to Charcot's hypnotic method, did not grasp the full implications of Breuer's experience until a decade later, when he developed the technique of free association. In part an extrapolation of the automatic writing promoted by the German Jewish writer Ludwig Börne a century before, in part a result of his own clinical experience with other hysterics, this revolutionary method was announced in the work Freud published jointly with Breuer in 1895,
Studien über Hysterie (Studies in Hysteria
).

By encouraging the patient to express any random thoughts that came associatively to mind, the technique aimed at uncovering hitherto unarticulated material from the realm of the psyche that Freud, following a long tradition, called the unconscious. Difficulty in freely associating—sudden silences, stuttering, or the like—suggested to Freud the importance of the material struggling to be expressed, as well as the power of what he called the patient's defenses against that expression. Such blockages Freud dubbed resistance, which had to be broken down in order to reveal hidden conflicts. Unlike Charcot and Breuer, Freud came to the conclusion, based on his clinical experience with female hysterics, that the most insistent source of resisted material was sexual in nature. And even more momentously, he linked the etiology of neurotic symptoms to the same struggle between a sexual feeling or urge and the psychic defenses against it.

At first, however, Freud was uncertain about the precise status of the sexual component in this dynamic conception of the psyche. In a now famous letter to Fliess of Sept. 2, 1897, he concluded that, rather than being
memories of actual events, these shocking recollections were the residues of infantile impulses and desires to be seduced by an adult. What was recalled was not a genuine memory but what he would later call a screen memory, or fantasy, hiding a primitive wish. That is, rather than stressing the corrupting initiative of adults in the etiology of neuroses, Freud concluded that the fantasies and yearnings of the child were at the root of later conflict.

In what many commentators consider Freud's master work,
Die Traumdeutung (The Interpretation of Dreams
), published in 1899, but given the date of the dawning century to emphasize its epochal character, Freud interspersed evidence from his own dreams with evidence from those recounted in his clinical practice. Freud contended that dreams played a fundamental role in the psychic economy. The mind's energy—which Freud called libido and identified principally, but not exclusively, with the sexual drive—was a fluid and malleable force capable of excessive and disturbing power. Needing to be discharged to ensure pleasure and prevent pain, it sought whatever outlet it might find. If denied the gratification provided by direct motor action, libidinal energy could seek its release through mental channels.

The Interpretation of Dreams
provides a hermeneutic for the unmasking of the dream's disguise, or dreamwork, as Freud called it. The manifest content of the dream, that which is remembered and reported, must be understood as veiling a latent meaning. Dreams defy logical entailment and narrative coherence, for they intermingle the residues of immediate daily experience with the deepest, often most infantile wishes. Yet they can be ultimately decoded, and their mystifying effects can be reversed.

In 1904 Freud published
Zur Psychopathologie des Alltagslebens
(
The Psychopathology of Everyday Life
), in which he explored such seemingly insignificant errors as slips of the tongue or pen (later colloquially called Freudian slips), misreadings, or forgetting of names. These errors Freud understood to have symptomatic and thus interpretable importance. But unlike dreams they need not betray a repressed infantile wish yet can arise from more immediate hostile, jealous, or egoistic causes.

In 1905 Freud extended the scope of this analysis by examining
Der Witz und seine Beziehung zum Unbewussten
(
Jokes and Their Relation to the Unconscious
). Invoking the idea of “joke-work” as a process comparable to dreamwork, he also acknowledged the double-sided quality of jokes, at once consciously contrived and unconsciously revealing. Insofar as jokes are more deliberate than dreams or slips, they draw on the rational dimension of the psyche that Freud was to call the ego as much as on what he was to call the id. Also in that year, Freud published the work that first thrust him into the limelight as the alleged champion of a pansexualist understanding of the mind.
Drei Abhandlungen zur Sexualtheorie (Three Contributions to the Sexual Theory
, later translated as
Three Essays on the Theory of Sexuality
) outlined in greater detail than before his reasons for emphasizing the sexual component in the development of both normal and pathological behaviour.

According to Freud, an originally polymorphous sexuality first seeks gratification orally through sucking at the mother's breast. Initially unable to distinguish between self and breast, the infant soon comes to appreciate its mother as the first external love object. After the oral phase, during the second year, the child's focus shifts to its anus, stimulated by the struggle over toilet training.
During the anal phase the child's pleasure in defecation is confronted with the demands of self-control. The third phase, lasting from about the fourth to the sixth year, he called the phallic.

In addition to the neurosis of hysteria, with its conversion of affective conflicts into bodily symptoms, Freud developed complicated etiological explanations for other typical neurotic behaviour, such as obsessive-compulsions, paranoia, and narcissism. These he called psychoneuroses, because of their rootedness in childhood conflicts, as opposed to the actual neuroses such as hypochondria, neurasthenia, and anxiety neurosis, which are due to problems in the present (the last, for example, being caused by the physical suppression of sexual release).

Freud developed the celebrated technique of having the patient lie on a couch, not looking directly at the analyst, and free to fantasize with as little intrusion of the analyst's real personality as possible. Restrained and neutral, the analyst functions as a screen for the displacement of early emotions, both erotic and aggressive. This transference onto the analyst is itself a kind of neurosis, but one in the service of an ultimate working through of the conflicting feelings it expresses. Only certain illnesses, however, are open to this treatment, for it demands the ability to redirect libidinal energy outward. The psychoses, Freud sadly concluded, are based on the redirection of libido back onto the patient's ego and cannot therefore be relieved by transference in the analytic situation. How successful psychoanalytic therapy has been in the treatment of psychoneuroses remains, however, a matter of considerable dispute.

Freud later attempted to clarify the relationship between his earlier topographical division of the psyche into the unconscious, preconscious, and conscious and his subsequent structural categorization into id, ego, and superego. The id was defined in terms of the most primitive urges for gratification in the infant, urges dominated by the desire for pleasure through the release of tension and the cathexis of energy. The id is ruled by what Freud called the primary process directly expressing somatically generated instincts. The secondary process that results leads to the growth of the ego, which follows what Freud called the reality principle in contradistinction to the pleasure principle dominating the id.

The last component in Freud's trichotomy, the superego, develops from the internalization of society's moral commands through identification with parental dictates. Only partly conscious, the superego gains some of its punishing force by borrowing certain aggressive elements in the id, which are turned inward against the ego and produce feelings of guilt. But it is largely through the internalization of social norms that the superego is constituted, an acknowledgement that prevents psychoanalysis from conceptualizing the psyche in purely biologistic or individualistic terms.

Freud's understanding of the primary process underwent a crucial shift in the course of his career. Initially he counterposed a libidinal drive that seeks sexual pleasure to a self-preservation drive whose telos is survival. But in 1914, while examining the phenomenon of narcissism, he came to consider the latter instinct as merely a variant of the former. Unable to accept so monistic a drive theory, Freud sought a new dualistic alternative. He arrived at the
speculative assertion that there exists in the psyche an innate, regressive drive for stasis that aims to end life's inevitable tension. This striving for rest he christened the Nirvana principle and the drive underlying it the death instinct, or Thanatos, which he could substitute for self-preservation as the contrary of the life instinct, or Eros.

(b. April 23, 1858, Kiel, Schleswig [Germany]—d. Oct. 4, 1947, Göttingen, W. Ger.)

G
erman theoretical physicist Max Planck originated quantum theory, which won him the Nobel Prize for Physics in 1918. Planck made many contributions to theoretical physics, but his fame rests primarily on his role as originator of the quantum theory. This theory revolutionized modern understanding of atomic and subatomic processes, just as Albert Einstein's theory of relativity revolutionized the understanding of space and time. Together they constitute the fundamental theories of 20th-century physics. Both have forced humans to revise some of their most cherished philosophical beliefs, and both have led to industrial and military applications that affect every aspect of modern life.

Planck's intellectual capacities were brought to a focus as the result of his independent study, especially of Rudolf Clausius's writings on thermodynamics.

Planck recalled that his “original decision to devote myself to science was a direct result of the discovery … that the laws of human reasoning coincide with the laws governing the sequences of the impressions we receive from the world about us; that, therefore, pure reasoning
can enable man to gain an insight into the mechanism of the [world]….” In other words, he deliberately decided to become a theoretical physicist at a time when theoretical physics was not yet recognized as a discipline in its own right. But he went further: he concluded that the existence of physical laws presupposes that the “outside world is something independent from man, something absolute, and the quest for the laws which apply to this absolute appeared … as the most sublime scientific pursuit in life.”

The first instance of an absolute in nature that impressed Planck deeply was the law of the conservation of energy, the first law of thermodynamics. Later, during his university years, he became equally convinced that the entropy law, the second law of thermodynamics, was also an absolute law of nature. The second law lay at the core of the researches that led him to discover the quantum of action, now known as Planck's constant
h
, in 1900.

One of the first problems that Planck attempted to solve concerned blackbody radiation. By the 1890s various experimental and theoretical attempts had been made to determine the spectral energy distribution—the curve displaying how much radiant energy is emitted at different frequencies for a given temperature of the blackbody. Planck was particularly attracted to the formula found in 1896 by his colleague Wilhelm Wien, and he subsequently made a series of attempts to derive “Wien's law” on the basis of the second law of thermodynamics. By October 1900, however, others had found definite indications that Wien's law, while valid at high frequencies, broke down completely at low frequencies.

Planck learned of these results just before a meeting of the German Physical Society on Oct. 19, 1900. He knew
how the entropy of the radiation had to depend mathematically upon its energy in the high-frequency region if Wien's law held there. He also saw what this dependence had to be in the low-frequency region in order to reproduce the experimental results there. Planck guessed, therefore, that he should try to combine these two expressions in the simplest way possible, and to transform the result into a formula relating the energy of the radiation to its frequency.

The result, which is known as Planck's radiation law, was hailed as indisputably correct. To Planck, however, it was simply a guess, a “lucky intuition.” If it was to be taken seriously, it had to be derived somehow from first principles. That was the task to which Planck immediately directed his energies, and by Dec. 14, 1900, he had succeeded—but at great cost. To achieve his goal, Planck found that he had to relinquish one of his own most cherished beliefs, that the second law of thermodynamics was an absolute law of nature.

In addition, Planck had to assume that the oscillators comprising the blackbody and re-emitting the radiant energy incident upon them could not absorb this energy continuously but only in discrete amounts, in quanta of energy; only by statistically distributing these quanta, each containing an amount of energy
h
v proportional to its frequency, over all of the oscillators present in the blackbody could Planck derive the formula he had hit upon two months earlier. He adduced additional evidence for the importance of his formula by using it to evaluate the constant
h
(his value was 6.55 × 10
^-27
erg-second, close to the modern value), as well as the so-called Boltzmann constant (the fundamental constant in kinetic theory and statistical mechanics), Avogadro's number, and the charge of the electron.