In Freudian psychology, Eros, also referred to in terms of libido , libidinal energy or love, is the life instinct innate in all humans. It is the desire to create life and favours productivity and construction. Eros battles against the destructive death instinct of Thanatos (death instinct or death drive).
In his final theory of the drives, Sigmund Freud made Eros a fundamental concept referring to the life instincts (narcissism and object libido), whose goals were the preservation, binding, and union of the organism into increasingly larger units.
"In this way the libido of our sexual instincts would coincide with the Eros of the poets and philosophers which holds all living things together." 
The term Eros, understood as a life instinct antagonistic to the death instinct, appeared for the first time in Beyond the Pleasure Principle,  where Freud used it to establish a dynamic polarity that would define a new instinctual dualism.
Our speculations have suggested that Eros operates from the beginning of life and appears as a 'life instinct' in opposition to the 'death instinct' which was brought into being by the coming to life of inorganic substance. These speculations seek to solve the riddle of life by supposing that these two instincts were struggling with each other from the very first.
In this essay Freud refers to the doctrine of the Greek physician and philosopher Empedocles of Agrigento (c. 490-430 B.C.E.), for whom the production of all things results from the interplay of two forces, Love and Discord, conceived of as the impersonal forces of attraction and repulsion. Yet Freud's theoretical innovation is more than the pure speculations of philosophy, biology, or physics. Revision of his concepts was called for by his experience in psychoanalytic practice. He posited within the organism a primal masochism derived from the action of the death instinct to account for certain clinical problems: ambivalence in affective life, nightmares associated with traumatic neurosis, masochism, and negative therapeutic reactions.
Freud's uses of the term Eros (86 of 88 occurrences, according to Guttman's Concordance) is contemporary with his final theory of the instincts developed after 1920. The word itself, with its multiple meanings, enabled Freud to combine many things that he had previously separated and contrasted: love between the sexes, self-love, love for one's parents or children, "friendship and love among mankind in general," "devotion to concrete objects and abstract ideas," and partial sexual drives (component instincts). This expanded concept of love led Freud to evoke, on several occasions (1920g, 1921c, 1924c, 1925e ), "the all-inclusive and all-preserving Eros of Plato's Symposium."
Although the concept of Eros, properly speaking, emerged late in Freud's work, this did not prevent him from claiming that all his earlier discoveries about sexuality can be seen in terms of Eros. Psychoanalysis showed that sexuality did not conceal "impulsion towards a union of the two sexes or towards producing a pleasurable sensation in the genitals," and that sexuality was thus different from genitality.
Though the term Eros does not appear in the original texts, two notes, one from 1925 in The Interpretation of Dreams (1900a) and the other from 1920 in Three Essays on the Theory of Sexuality (1905d), reinforce the use of "Eros" as a synonym for "sexual" in the discovery of psychoanalysis: "The situation would be different if 'sexual' was being used by my critics in the sense in which it is now commonly employed in psychoanalysts—in the sense of 'Eros"' (1900a, note 1925, p. 161). Freud even justified his failure to use the word earlier: "Anyone who considers sex as something mortifying and humiliating to human nature is at liberty to make use of the more genteel expressions 'Eros' and 'erotic.' I might have done so myself from the first and thus spared myself much opposition. But I did not want to, for I like to avoid concessions to faintheartedness. One can never tell where that road may lead one; one gives way first in words, then little by little in substance too" (1921c, p. 91). Occurrences of the terms "Eros" (after 1920) and "eroticism" (after 1894) overlap in Freud's writings without ever leaving the field of sexuality.
Freud early on recognized the erotic character of repressed representations that lie at the heart of neurotic symptoms. He cites "the case of a girl, who blamed herself because, while she was nursing her sick father, she had thought about a young man who made a slight erotic impression on her" (1894a, p. 48), and who is then constrained to treat this unwanted representation of a sexual nature as if it had "never occurred." Freud conceived mental conflict as a moral conflict in which the troublemaker Eros stirs up trouble in the form of a symptom. He saw sexuality as a trauma that goes far beyond the well-known scenes of sexual seduction. Eros forces the ego to defend itself and thus participates in the division and fragmentation of the psyche. Repressed erotic representations later return in the form of symptoms or compromise formations that substitute for sexual activity or "precipitates of earlier experiences in the sphere of love" (1910a, p. 51). Such instances of deferred or aborted love are remote from sexual attraction and genital activity. Sexuality exists from infancy, is fundamentally perverse and polymorphous, and consists of a bundle of partial sexual drives that seek satisfaction independently of one another, in autoerotic fashion. The oral drive, for example, is seen as a mouth that kisses itself.
The 1920 footnote in Three Essays on the Theory of Sexuality retroactively referring to Eros (1905d, p. 266n) serves Freud's theoretical interests: to recognize infantile sexuality as something distinct from genitality, to emphasize the diphasic nature of sexual life, and to provide the concept of the drives with a mythical status, infantile in appearance and dominated by an ongoing and insatiable quest. Here Eros appears to conflict with the ego's instinct for self-preservation. The Oedipus complex determines the outcome of this conflict through the possibilities it offers for orienting the libido toward a sexual object (one that is no longer only sexual) by means of the phallus. The Oedipus complex is responsible for ensuring that the subject becomes satisfied in love after the reorganization at puberty, when the partial drives (component instincts) are enlisted in the service of an organized genital apparatus. Failing this, the subject will fall ill unless an alternative object is found through sublimation. Eros is not only a cause of symptoms but can also become the means for their relief. The theoretical model of Eros as healer is beautifully illustrated in Delusions and Dreams in Jensen's "Gradiva" (1907a ).
Love was also at the center of the psychoanalytic experiment from the time of its initial discovery via transference. In the middle period of the development of psychoanalysis (1912-1915), the homage to love in Delusions and Dreams would butt up against its limitations in a theory of transference, which shows love to support resistance to remembering, and hence to analysis. Moreover, Freud discovered in cases of sexual impotence of psychological origin that a conflict exists between the "affectionate current" and the "sexual current": "Where they love they do not desire, and where they desire they cannot love" (1912d, p. 183). This text anticipates Freud's comments in "On Narcissism: An Introduction" (1914c). In this text, Freud saw the narcissistic libido as conflicting with erotic love of the object: Narcissus versus Eros. The ego claims a place among the sexual objects, and the self-preservation instincts have a libidinal nature. What distinguishes Eros is its link with objects: "A strong egoism is a protection against falling ill, but in the last resort we must begin to love in order not to fall ill, and we are bound to fall ill, if, in consequence of frustration, we are unable to love" (1914c, p. 85).
Beyond the Pleasure Principle (Freud, 1920g) overturned these earlier constructions. The theory of a death instinct, which worked in silence, forced Freud to combine the ego instincts and sexual instincts directed at objects, grouping them under the umbrella of a single force whose goal was union: Eros. Such an Eros is no longer a troublemaker, a divisive agent that disturbs the mental apparatus. It is the power of creation, of reproduction; it makes existence possible and postpones the return to an inorganic state. When discussing the life-preserving sexual instincts (object libido and ego), Freud explicitly refers to the myth of Eros recounted by Aristophanes in Plato's Symposium. But the life and death instincts rarely come into play in isolation: They form various amalgams in which each attempts to make use of the other's strength to its own advantage. Freud shows that moral masochism, for example, "becomes a classical piece of evidence for the existence of fusion of instinct. Its danger lies in the fact that it originates from the death instinct and corresponds to the part of that instinct which has escaped being turned outwards as an instinct of destruction. But since, on the other hand, it has the significance of an erotic component, even the subject's destruction of himself cannot take place without libidinal satisfaction" (1924a). In Freud's last work, it is as if the scandal of the discovery of sexuality was displaced in favor of the theoretical innovation of the death instinct. Eros as the embodiment of Aristophanes' myth or Empedocles' theories appears to get the better of Eros as the embodiment of desire, an Eros whose birth is given in the myth recounted by Diotima in The Symposium.
Jacques Lacan distances, without completely separating, love and desire (Eros). Love is the mirage in which desire is caught. The phallus is the fulcrum between the object that gives rise to desire and the part of the subject, minus language, that is forever lost. "Therefore, to love is to give what one does not have, and we can only love by acting as if we don't have, even if we do" (Lacan, 1991).
- Animus-Anima (analytical psychology)
- Beyond the Pleasure Principle
- Binding/unbinding of the instincts
- Civilization and Its Discontents
- Genital love
- German romanticism and psychoanalysis
- Life instinct (Eros)
- Marcuse, Herbert
- Freud, 1920g, p. 50
- p. 61
- 1925e, p. 218
- 1925e, p. 218
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- ——. (1900a). The interpretation of dreams. SE, 4: 1-338]]
- [[5: 339-625.
- ——. (1905d). Three essays on the theory of sexuality. SE, 7: 123-243.
- ——. (1907a ). Delusions and dreams in Jensen's "Gradiva." SE, 9: 1-95.
- ——. (1914c). On narcissism: An introduction. SE, 14: 67-102.
- ——. (1920g). Beyond the pleasure principle. SE, 18: 1-64.
- ——. (1921c). Group psychology and the analysis of the ego. SE, 18: 65-143.
- ——. (1924a). Letter to Le Disque Vert. SE, 19: 290-290.
- ——. (1924b ). Neurosis and psychosis. SE, 19: 147-153.
- ——. (1924c). The economic problem of masochism. SE, 19: 155-170.
- ——. (1925e ). The resistances to psycho-analysis. SE, 19: 211-222.
- Lacan, Jacques. (1991). Le séminaire. Book 8: Le transfert. Paris: Seuil.