Ontogenesis is a theory of the development and structuring of the individual that takes into account the individual's origins and the conditions of his or her development. Sigmund Freud always associated the ontogenesis of the human subject with phylogenesis, adopting a biogenetic perspective.

Ontogenesis comprises the developmental processes and acquisitions specific to the individual, in constrast to phylogenesis, which involves the processes of evolution and acquisition particular to a species. Ontogenesis and phylogenesis are not independent from one another: Individual acquisitions are only possible within the fixed limits of the species.

Defining ontogenesis, or the development of the individual, requires examination of what constitutes the mind and what the primary conditions of its organization are. What is called for is nothing less than a clear understanding of the origins, developmental stages, and earlier states of an individual's history.

At the end of the nineteenth century, psychology found fertile soil in Darwin's overarching theory of the evolution of animal species. It was believed at the time that the level of functioning of an earlier species was retained in a virtual state in later species. As Ernst Haeckel famously put it: "Ontogeny recapitulates phylogeny." Haeckel and other nineteenth-century evolutionist thinkers held that in human beings, the development of the fetus to adulthood (ontogeny) paralleled, in brief, the entire history of the species (phylogeny).

Meanwhile, the British neurologist John Hughlings Jackson hypothesized a hierarchical organization of the central nervous system, showing that the suspension of control from the higher centers freed up archaic automatic responses in the lower centers that correspond to earlier phases in development. Freud drew inspiration from this model with the notion of "regression." In France, Henri Ey based his theory of organodynamism on Jackson's "dissolutions."

At the time, the prevailing idea was that some functions with adaptive value for lower animal species persisted in a virtual state and could be reactualized by pathology: failure of control at a higher level liberated lower levels in the hierarchy. The idea that pathology liberated a less differentiated, more "automatic" level of functioning, dating from an earlier stage in individual or species development, influenced many authors, including Freud and Pierre Janet.

Thus Freud, from his earliest writings, implicitly adopted a biogenetic conception of human sexual development. Along with Wilhelm Stekel, Wilhelm Bölsche, Granville Stanley Hall, and many others, he applied Haeckel's "fundamental biogenetic law" to the question of sexual development.

If the child, in its growth, recapitulates the history of the species, Freud concluded that it must, by extension, recapitulate the sexual history of the species. In other words, the prepubescent human being must have the innate capacity to experience all the archaic forms of sexual pleasure that characterized the adult stages of our distant ancestors. In "Some Thoughts on Development and Regression—Aetiology," the twenty-second of his Introductory Lectures (1916-1917a), Freud wrote of the development of the ego and libido that "both of them are at bottom heritages, abbreviated recapitulations of the development which all mankind has passed through from its primaeval days over a long period of time" (p. 354).

This biogenetic logic not only subtended Freud's thoughts on the "polymorphously perverse" nature of infantile sexuality, but also later buttressed other developments in his theory. The concepts of "fixation" (arrested or inhibited development), "regression" (linked to Jackson's general notion of "dissolution"), and "perseveration of early impressions" (after Wilhelm Roux's model of embryological experiments) all emerged from a developmental perspective to account for the organization of the neuroses.

Freud pursued the logic of recapitulation in a footnote added in 1915 to his Three Essays on the Theory of Sexuality (1905d), where he insisted that each major "pregenital" stage in infantile sexual development preserved a specific inheritance from this phylogenetic influence. From the same perspective, mental pathology was considered a return of past stages of ontogenetic and phylogenetic development that are integrated, and at the same time rediscovered. For Freud, symptom formation actualized the past, and psychoanalytic treatment was itself a therapeutic form of remembering.

Seeking the origins of Oedipal conflict, Freud detailed a series of three primal fantasies—seduction, castration, and the primal scene—that he considered to be a given from the outset and at the source of all mental organization, beyond the traumatic events of the individual's history. The presumed universality of the Oedipus complex led him to believe that in each individual there was an embryonic version of these fantasies that are found in all cultures, as the phylogenetically transmitted trace of the murder of the father by the primitive horde.

The neo-Lamarckian perspective of Freud and his phylogenetic theories have received a good deal of criticism, despite Frank J. Sulloway's study, Freud—Biologist of the Mind (1979), which presented the full scope of Freud's constructions. The fact is that in early twenty-first century cultural and linguistic transmission, along with communication in one way or another, from the parental or grandparental unconscious, are far more readily invoked to define the way in which the psyche's earliest constitutive fantasies originate than a hypothetical inscription in the genetic material of the species. Research on transgenerational effects (Kaës, 1993) takes this direction, as does Jean Laplanche's "general theory of seduction" which argues that the maternal unconscious transmits sexualized messages, or "enigmatic signifiers," to the child.

Present day research is concerned less with discovering the ultimate origins of the formation of the individual than with accounting for the conditions under which it comes about. As of 2005, the ontogenetic approach—that is, research into the development of the individual or into the genesis of the Oedipus complex—concentrates on two main lines of inquiry. The first is libidinal development, taking into consideration the successive phases of mental organization, with a focus on the predominant erotogenic zone around which psychic excitation is centered and fantasies organized. The second focuses on the development of object relations in their relationship with the development of the ego.

JEAN-FRANÇOIS RABAIN

See also: Civilization and its Discontents; "Claims of Psycho-Analysis to Scientific Interest; Cultural transmission; Darwin, Darwinism, and psychoanalysis; Fatherhood; Processes of development; Heredity of acquired characters; Intergenerational; Lack of differentiation; Maternal reverie, capacity for; Phylogenesis; Prehistory; Primitive horde; Thalassa. A Theory of Genitality; Totem and Taboo.