Sigmund Freud was an Austrian neurologist and the founder of the psychoanalytic school of psychology.

The theories distinctive of this school generally included the following hypotheses: (1) that human development is best understood in terms of changing objects of sexual desire, (2) that the psychic apparatus habitually represses wishes, usually of a sexual or aggressive nature, whereby they become preserved in one or more unconscious systems of ideas, (3) that unconscious conflicts over repressed wishes have a tendency to express themselves in dreams, parapraxes ("Freudian slips"), and symptoms, (4) that unconscious conflicts are the source of neuroses, and (5) that neuroses can be treated through bringing the unconscious wishes and repressed memories to consciousness in psychoanalytic treatment.
He is commonly referred to as "the father of psychoanalysis."

Life
Sigismund Schlomo Freud was born into an Ashkenazi Jewish family in Freiberg (Príbor), Moravia, the Austrian Empire (now the Czech Republic). In 1877, at the age of 21, he abbreviated his given name to "Sigmund." Although he was the first-born of three brothers and five sisters among his mother's children, Sigmund had older half-brothers from his father's previous marriage. His family had limited finances and lived in a crowded apartment, but his parents made every effort to foster his intellect (often favoring Sigmund over his siblings), which was apparent from an early age. Sigmund was ranked first in his class in six of eight years of schooling. He went on to attend the University of Vienna at 17, in 1873–1881 despite intense anti-Semitism in Austria.

Overall, little is known of Freud's early life, as he destroyed his personal papers at least twice, once in 1885 and again in 1907. Additionally, his later papers were closely guarded in the Sigmund Freud Archives and only available to his official biographer Ernest Jones and a few other members of the inner circle of psychoanalysis.

In 1886, Freud returned to Vienna and, after opening a private practice specializing in nervous and brain disorders, he married. He experimented with hypnotism with his most hysteric and neurotic patients, but he eventually gave up the practice. He found that he could get his patients to talk by putting them on a couch and encouraging them to say whatever came into their minds (a practice termed free association).

In his 40s, Freud "had numerous psychosomatic disorders as well as exaggerated fears of dying and other phobias" (Corey 2001, p. 67). During this time Freud was involved in the task of exploring his own dreams, memories, and the dynamics of his personality development. During this self-analysis, he came to realize the hostility he felt towards his father (Jacob Freud), and "he also recalled his childhood sexual feelings for his mother (Amalia Freud), who was attractive, warm, and protective" (Corey 2001, p. 67). Corey (2001) considers this time of emotional difficulty to be the most creative time in Freud's life.

After publishing some successful books on the unconscious mind in 1900 and 1901, Freud was appointed to a professorship at the University of Vienna and began to develop a loyal following. Freud had little tolerance for colleagues who diverged from his psychoanalytic doctrines, however. For example, he attempted to expel those who disagreed with the movement or even refused to accept certain aspects of his theory which he considered central (Corey, 2001): the most notable examples are Carl Jung and Wilhelm Reich.

Following the Nazi German Anschluss, Freud fled Austria with his family with the financial help of his patient and friend Princess Marie Bonaparte. On June 4th, 1938, they were allowed across the border into France and then they traveled from Paris to Hampstead, London, England, where they lived at 20 Maresfield Gardens (now the Freud Museum). As he was leaving Germany, Freud was required to sign a statement that he had been treated respectfully by the Nazis.

Freud smoked cigars for most of his life; even after having his jaw removed due to malignancy, he continued to smoke until his death on September 23, 1939. He smoked an entire box of cigars daily. After contracting cancer of the mouth in 1923 at the age of 67, he underwent over 30 operations to treat the disease. In the end, Freud could no longer tolerate the pain associated with his cancer. He requested that his personal physician visit him at his London home. Freud's death was by a physician-assisted morphine overdose.

Family/descendants
Sigmund Freud's daughter Anna Freud was also a distinguished psychologist, particularly in the fields of child and developmental psychology. Sigmund is the grandfather of painter Lucian Freud and comedian, politician and writer Clement Freud, and the great-grandfather of journalist Emma Freud, fashion designer Bella Freud and media magnates Matthew Freud and Ria Willems.

Sigmund Freud was also both a blood uncle and an uncle-in-law to public relations and propaganda wizard Edward Bernays. Bernays's mother, Anna Freud Bernays, was sister to Sigmund. Bernays's father, Ely Bernays, was brother to Sigmund's wife, Martha Bernays Freud.

Innovations
Freud has been influential in two related, but distinct ways. He simultaneously developed a theory of the human mind and human behavior, and clinical techniques for attempting to help neurotics.

Early work
A lesser known interest of Freud's was neurology. He was an early researcher on the topic of cerebral palsy, then known as "cerebral paralysis". He published several medical papers on the topic. He also showed that the disease existed far before other researchers in his day began to notice and study it. He also suggested that William Little, the man who first identified cerebral palsy, was wrong about lack of oxygen during the birth process being a cause. Instead, he suggested that complications in birth were only a symptom of the problem. It was not until the 1980s that his speculations were confirmed by more modern research.

Freud was an early user and proponent of cocaine as a stimulant. He wrote several articles on the antidepressant qualities of the drug, and he was influenced by his friend and confidant, Wilhelm Fliess, who recommended cocaine for the treatment of the "nasal reflex neurosis." Fliess operated on Freud and a number of Freud's patients whom he believed to be suffering from the disorder. Emma Eckstein underwent disastrous nasal surgery by Fliess.

Freud felt that cocaine would work as a cure-all for many disorders, and wrote a well-received paper, "On Coca", explaining its virtues. He prescribed it to his friend Ernst von Fleischl-Marxow to help him beat a morphine addiction he had acquired while treating a disease of the nervous system. Freud also recommended it to many of his close family and friends. He narrowly missed out on obtaining scientific priority for discovering cocaine's anesthetic properties (of which Freud was aware but on which he had not written extensively), after Karl Koller, a colleague of Freud's in Vienna, presented a report to a medical society in 1884 outlining the ways in which cocaine could be used for delicate eye surgery.

Freud was bruised by this, especially because this would turn out to be one of the only safe uses of cocaine, as reports of addiction and overdose began to filter in from many places in the world. Freud's medical reputation became somewhat tarnished for his early enthusiasm. Furthermore, Freud's friend Fleischl-Marxow developed an acute case of "cocaine psychosis" as a result of Freud's prescriptions and died a few years later. Freud felt great regret over these events, which later biographers have dubbed "The Cocaine Incident".

Freud hoped that his research would provide a solid scientific basis for his therapeutic technique. The goal of Freudian therapy, or psychoanalysis, was to bring to consciousness repressed thoughts and feelings. According to some of his successors, including his daughter Anna Freud, the goal of therapy is to allow the patient to develop a stronger ego; according to others, notably Jacques Lacan, the goal of therapy is to lead the analysand to a full acknowledgment of his or her inability to satisfy the most basic desires.

Classically, the bringing of unconscious thoughts and feelings to consciousness is brought about by encouraging the patient to talk in free association and to talk about dreams. Another important element of psychoanalysis is a relative lack of direct involvement on the part of the analyst, which is meant to encourage the patient to project thoughts and feelings onto the analyst. Through this process, transference, the patient can reenact and resolve repressed conflicts, especially childhood conflicts with (or about) parents.

The unconscious
Perhaps the most significant contribution Freud has made to modern thought is his conception of the dynamic unconscious. During the 19th century, the dominant trend in Western thought was positivism, the belief that people could ascertain real knowledge concerning themselves and their environment and judiciously exercise control over both. Freud, however, suggested that such declarations of free will are in fact delusions; that we are not entirely aware of what we think and often act for reasons that have little to do with our conscious thoughts. The concept of the unconscious was groundbreaking in that he proposed that awareness existed in layers and that there were thoughts occurring "below the surface." Dreams, which he called the "royal road to the unconscious", provided the best access to our unconscious life and the best illustration of its "logic", which was different than the logic of conscious thought. Freud developed his first topology of the psyche in The Interpretation of Dreams where he proposed the argument that the unconscious exists and described a method for gaining access to it. The Preconscious was described as a layer between conscious and unconscious thought—that which we could access with a little effort. Thus for Freud, the ideals of the Enlightenment, positivism, and rationalism could be achieved through understanding, transforming, and mastering the unconscious, rather than through denying or repressing it.

Crucial to the operation of the unconscious is "repression." According to Freud, people often experience thoughts and feelings that are so painful that people cannot bear them. Such thoughts and feelings—and associated memories—could not, Freud argued, be banished from the mind, but could be banished from consciousness. Thus they come to constitute the unconscious. Although Freud later attempted to find patterns of repression among his patients in order to derive a general model of the mind, he also observed that individual patients repress different things. Moreover, Freud observed that the process of repression is itself a non-conscious act (in other words, it did not occur through people willing away certain thoughts or feelings). Freud supposed that what people repressed was in part determined by their unconscious. In other words, the unconscious was for Freud both a cause and effect of repression.

Later, Freud distinguished between three concepts of the unconscious: the descriptive unconscious, the dynamic unconscious, and the system unconscious. The descriptive unconscious referred to all those features of mental life of which we are not subjectively aware. The dynamic unconscious, a more specific construct, referred to mental process and contents which are defensively removed from consciousness as a result of conflictual forces or "dynamics". The system unconscious denoted the idea that when mental processes are repressed, they become organized by principles different than those of the conscious mind, such as condensation and displacement.

Eventually, Freud abandoned the idea of the system unconscious, replacing it with the concept of the id (discussed below). Throughout his career, however, he retained the descriptive and dynamic conceptions of the unconscious.

Psychosexual development
Freud also believed that the libido developed in individuals by changing its object, a process designed by the concept of sublimation. He argued that humans are born "polymorphously perverse," meaning that any number of objects could be a source of pleasure. He further argued that, as humans developed, they become fixated on different and specific objects through their stages of development—first in the oral stage (exemplified by an infant's pleasure in nursing), then in the anal stage (exemplified by a toddler's pleasure in controlling his or her bowels), then in the phallic stage. Freud argued that children then passed through a stage in which they fixated on the mother as a sexual object, known as the Oedipus Complex but that the child eventually overcame and repressed this desire because of its taboo nature. (The lesser known Electra complex refers to such a fixation upon the father.)

Freud hoped to prove that his model was universally valid and thus turned to ancient mythology and contemporary ethnography for comparative material. Freud named his new theory the Oedipus Complex after the famous Greek tragedy Oedipus Rex by Sophocles.“I found in myself a constant love for my mother, and jealousy of my father. I now consider this to be a universal event in childhood,” Freud said. Freud sought to anchor this pattern of development in the dynamics of the mind. Each stage is a progression into adult sexual maturity, characterized by a strong ego and the ability to delay gratification. (see Three Essays on the Theory of Sexuality.) He used the Oedipus conflict to point out how much he believed that people desire incest and must repress that desire. The Oedipus conflict was described as a state of psychosexual development and awareness. He also turned to anthropological studies of totemism and argued that totemism reflected a ritualized enactment of a tribal Oedipal conflict.

No discussion of Sigmund Freud is complete without some mention of his highly influential and controversial views on the role and psychology of women. Freud was an early champion of both sexual freedom and education for women (Freud, "Civilized Sexual Morality and Modern Nervousness"). Some feminists, however, have argued that at worst his views of women's sexual development set the progress of women in Western culture back decades, and that at best they lent themselves to the ideology of female inferiority. Believing as he did that women were a kind of mutilated male, who must learn to accept her deformity (the lack of a penis) and submit to some imagined biological imperative, he contributed to the vocabulary of misogyny. Terms such as "penis envy" and "castrating" (both used to describe women who attempted to excel in any field outside the home) contributed to discouraging women from obtaining education or entering any field dominated by men, until the 1970s.

On the other hand, feminist theorists such as Juliet Mitchell, Nancy Chodorow, Jessica Benjamin, Jane Gallop, and Jane Flax have argued that psychoanalytic theory is essentially related to the feminist project and must, like other theoretical traditions, be adapted by women to free it from vestiges of sexism. Freud's views are still being questioned by people concerned about women's equality. Another feminist who finds potential use of Freud's theories in the feminist movement is Shulamith Firestone. In "Freudianism: The Misguided Feminism", she discusses how Freudianism is essentially completely accurate, with the exception of one crucial detail: everywhere that Freud writes "penis", the word should be replaced with "power".

It is interesting to note that originally Freud believed childhood sexual abuse to be the cause of hysteria—but he then recanted this so-called "seduction theory" ("The Index of Sexual Abuse"), claiming that he had found many cases in which apparent memories of childhood sexual abuse were based more on imagination than on real events. Instead he began to emphasize the Oedipus Theory, which asserts that everyone unconsciously wishes to possess their parents.

Id, ego, superego
In his later work, Freud proposed that the psyche was divided into three parts: Id, Ego, and Superego. The unconscious Id (Latin, = "it" = es in the original German) represented primary process thinking—our most primitive need gratification type thoughts. The Superego ( also unconscious) represented our socially-induced morals and ethics and counteracted the Id. Freud based the term Id on the work of Georg Groddeck. The Ego (conscious and ego ideal )stands in between both to balance our primitive needs and our moral/ethical beliefs. A healthy Ego provides the ability to adapt to reality and interact with the outside world in a way that accommodates both Id and Superego. The general claim that the mind is not a monolithic or homogeneous thing continues to have an enormous influence on people outside of psychology. Freud was especially concerned with the dynamic relationship between these three parts of the mind, in particular, how they enter into conflict with each other.

Defense mechanisms
According to Freud, the defense mechanisms are the method by which the ego can solve the conflicts between the superego and the id. The use of the mechanisms required Eros (named after the Greek god of love; Cupid in Roman mythology), and they are helpful if moderately used. The use of defense mechanisms may attenuate the conflict between the id and superego, but their overuse or reuse rather than confrontation can lead to either anxiety or guilt which may result in psychological disorders such as depression. His daughter Anna Freud had done the most significant work on this field, yet she credited Sigmund with defense mechanisms, as he began the work. The defense mechanisms include: denial, reaction formation, displacement, repression/suppression (the proper term), projection, intellectualisation, rationalisation, compensation, sublimation and regressive emotionality.

Denial occurs when someone fends off awareness of an unpleasant truth or of a reality that is a threat to the ego. For example, a student may have received a bad grade on a report card but tells himself that grades don't matter. (Some early writers argued for a striking parallel between Freudian denial and Nietzsche's ideas of ressentiment and the revaluation of values that he attributed to "herd" or "slave" morality.)

Reaction formation takes place when a person takes the opposite approach consciously compared to what that person wants unconsciously. For example, someone may engage in violence against another race because, that person claims, the members of the race are inferior, when unconsciously it is that very person who feels inferior.

Displacement takes place when someone redirects emotion from a "dangerous" object to a "safe" one, such as punching a pillow to avoid hitting a friend.

Repression occurs when an experience is so painful (such as war trauma) that it is subconsciously forced from consciousness, while suppression is a conscious effort to do the same.

Psychological projection occurs when a person "projects" his or her own undesirable thoughts, motivations, desires, feelings—basically parts of oneself—onto someone or something else. An example of this would be to say that Alice doesn't like Bob, but rather than to admit she doesn't like Bob, she will project her sentiment onto Bob, saying that Bob doesn't like her.

Intellectualisation involves removing one's self, emotionally, from a stressful event. Intellectualisation is often accomplished through rationalisation rather than accepting reality, one may explain it away to remove one's self.

Rationalization involves constructing a logical justification for a decision that was originally arrived at through a different mental process. For example, Jim may have bought a tape player to listen to self-help tapes, but he tells his friends he bought it so that he can listen to classic rock mixes for fear of his actual reason being rejected.

Compensation occurs when someone takes up one behavior because one cannot accomplish another behavior. For example, the second born child may clown around to get attention since the older child is already an accomplished scholar.
Sublimation is the channeling of impulses to socially accepted behaviours. For instance, the use of a dark, gloomy poem to describe life by such poets as Emily Dickinson.

The life and death instincts
Freud believed that humans were driven by two conflicting central desires: libidinal energy (Eros) and the death drive (Thanatos). Freud's description of Eros/Libido included all creative, life-producing drives. The Death Drive (or death instinct) represented an urge inherent in all living things to return to a state of calm, or, ultimately, of non-existence. The presence of the Death Drive was only recognized in his later years, and the contrast between the two represents a revolution in his manner of thinking.

Psychology of religion
Freud gave explanations of the genesis of religion in his writings. In “Totem and Taboo”, he proposed that humans originally banded together in “primal hordes”, consisting of a male, a number of females and the offspring of this polygamous arrangement. According to Freud’s psychoanalytical theory, a male child early in life has sexual desires for his mother – the Oedipus Complex – which he held to be universal. The father is protective, so the males love him, but they are also jealous of their father because of his relationship with their mothers.

Finding that individually they could not defeat the father-leader, they banded together to kill him. After the murder, they ate him in a ritual meal, thereby taking into themselves the substance of the father’s hated power – but the subsequent guilt of the sons leads them to elevate his memory and to worship him. The super-ego then takes the place of the father as the source of internalised authority. A ban was then put upon incest and upon marriage within the clan, and a symbolic animal sacrifice was substituted for the ritual killing of a human being.

In Moses and Monotheism Freud reconstructed biblical history in accord with his general theory, but biblical scholars and historians would not accept his account since it was in opposition to the point of view of the accepted criteria of historical evidence. His ideas were also developed in The Future of an Illusion. When Freud spoke of religion as an illusion, he maintained that it is a fantasy structure from which a man must be set free if he is to grow to maturity; and in his treatment of the unconscious he moved toward atheism.

Freud's legacy

Psychotherapy
Freud trained as a medical doctor, and as such, he believed his research methods and conclusions were scientific. However, his research and practice were condemned by many of his peers, as well as later psychologists and academics. Some, like Juliet Mitchell, have suggested that this is because his basic claim, that many of our conscious thoughts and actions are motivated by unconscious fears and desires, implicitly challenges universal and objective claims about the world. Some proponents of science conclude that this invalidates Freudian theory as a means of interpreting and explaining human behavior. Psychoanalysis today maintains the same ambivalent relationship with medicine and academia that Freud experienced during his life.

Current psychotherapists, who seek to treat mental illness, relate to Freudian psychoanalysis in different ways. Some psychotherapists have modified this approach and have developed a variety of "psychodynamic" models and therapies. Other therapists reject Freud's model of the mind, but have adapted elements of his therapeutic method, especially his reliance on patients' talking as a form of therapy. Experimental psychologists generally reject Freud's methods and theories. Psychiatrists train as medical doctors, but—like most medical doctors in Freud's time—most reject his theory of the mind, and generally rely more on psychoactive drugs than talk in their treatments.

Freud's psychological theories are hotly disputed today and many leading academic and research psychiatrists regard him as a charlatan, but there are also many leading academic and research psychiatrists who agree with the core of his work. Psychiatric disorders are often considered purely diseases of the brain, the etiology of which is principally genetic. This view emphasizes constitutional factors in mental illness. Freud believed that the vast majority of disorders result from a combination of constitutional and environmental factors, the relative importance of each varying from one person to another.

Freud recognized a political dimension to the psyche and to psychotherapy. He closed his 1929 book, Civilization and Its Discontents, with a reflection that not only individuals, but entire societies, may be proper subjects for psychoanalysis and psychotherapy.

Philosophy
Freud introduced three concepts that represent a break with prior Western philosophy, whatever the value of psychoanalysis as a form of psychotherapy.

He created a model of mental processes that breaks with the Cartesian cogito. For Freud, thought emerges from processes that are not accessible to the subject itself through direct introspection. In a more historicized sense, Karl Marx's analysis of ideology precedes Freud's, but Freud makes non-transparency of subjectivity more fundamental. Psychosexual history (in Freud's view) and membership in a social class (in Marx's view) lie at the core of the goals people have and the ideas they use to justify them.

Freud examined the "rationality" to be found even in material regarded as thoroughly inscrutable, irrational and meaningless, such as dreams, slips, neurotic symptoms, and the verbal productions of psychotics. Conversely, he discovered "irrationality" (i.e., purely arbitrary and idiosyncratic elements) even in material that is manifestly "rational" (i.e., work activities, political philosophy, conventional social behavior).

Freud introduced a novel discursive technique in the talking cure. Psychoanalysis enables people to mitigate distress through the indirect revelation of unconscious content. The process of psychoanalysis reveals retrospectively how individuals unconsciously contribute to problems they encounter, according to specific logics of condensation and transference.

Critical reactions
Freud's model of psychosexual development has been criticized from different perspectives. Some have attacked Freud's claim that infants are sexual beings (and, implicitly, Freud's expanded notion of sexuality). Others have accepted Freud's expanded notion of sexuality, but have argued that this pattern of development is not universal, nor necessary for the development of a healthy adult. Instead, they have emphasized the social and environmental sources of patterns of development. Moreover, they call attention to social dynamics Freud de-emphasized or ignored (such as class relations). This branch of Freudian critique owes a great deal to the work of Herbert Marcuse.

Some criticize Freud's rejection of positivism. The philosopher of science Karl Popper formulated a method to distinguish science from non-science. For Popper, all proper scientific theories are potentially falsifiable. If a theory is incapable of being falsified, then it cannot be considered scientific. Popper pointed out that Freud's theories of psychology can always be "verified", since no type of behaviour could ever falsify them. Although Popper's demarcation between science and non-science is widely accepted among scientists, it remains a controversial one itself within philosophy of science and philosophy in general. In academic psychology, a distinction is generally made between theories (which are considered too abstract to be falsifiable) and specific hypotheses (which derive from a theory and may be tested by research).

Patients
This is a partial list of patients whose case studies were published by Freud, with pseudonyms substituted for their names:

Cäcilie M. = Anna von Lieben
Dora = Ida Bauer (1882–1945)
Frau Emmy von N. = Fanny Moser
Fräulein Elizabeth von R.
Fräulein Katharina = Aurelia Kronich
Fräulein Lucy R.
Little Hans = Herbert Graf (1903–1973)
Rat Man = Ernst Lanzer (1878–1914)
Wolf Man = Sergei Pankejeff (1887–1979)
Dr.Otto
Daniel Paul Schreber (1842–1911)
Other patients:
H.D. (1886–1961)
Emma Eckstein
Gustav Mahler (1860–1911)