Jones's first theoretical paper, read at Salzburg in 1908, brought the term rationalization into psychoanalysis. Starting from Freud's demonstration that many mental processes have causes the person neither knows nor will admit, he sorted the mechanisms that hide these causes into two classes. In the first the person holds that no explanation is needed, as when slips and chance actions are put down to accident. Jones read the resistance to asking where such acts come from as a sign that their source is unacceptable, and so brought parapraxes into the same scheme. In the second class the person supplies a plausible but false explanation, because everyone needs to give a connected and rational account of themselves. False explanations formed mainly for oneself he called evasions; those formed with an eye to the opinion of one's circle he called rationalisations (Rationalization in Every-Day Life2). The paper became the opening chapter of Papers on Psycho-Analysis. That book's other papers contrast psychoanalysis with suggestion, which in Jones's account works through a transference of positive feeling onto the physician and replaces symptoms with dependence. They also set out Freud's theory of dreams, of the neuroses and of sublimation, and treat neurotic symptoms as failed or imperfect sublimations (Papers on Psycho-Analysis3).
In 1910, in the American Journal of Psychology, Jones worked up into a full study a hypothesis Freud had sketched in a footnote to The Interpretation of Dreams5: that Hamlet's delay springs from the Oedipus complex. He reviewed the critical literature and rejected explanations from Hamlet's temperament or from external obstacles, describing Hamlet's state as a "specific aboulia", an inability to will one particular act. By killing Hamlet's father and marrying his mother, Claudius had carried out Hamlet's own repressed wishes, so the duty to kill him was bound up with those wishes and inhibited along with them. Jones also placed the story among the hero myths studied by Rank and Abraham, and linked the play to the death of Shakespeare's father in 1601 (The Œdipus-Complex as an Explanation of Hamlet's Mystery6). He later expanded the essay, eventually into the book Hamlet and Oedipus (1949).
The Theory of Symbolism7 (1918) expanded a lecture given to the British Psychological Society in 1916. It reserved the term symbolism for one kind of indirect representation, the unconscious kind, as distinct from metaphor, simile and emblem. Modifying criteria proposed by Rank and Sachs, Jones held that a true symbol represents unconscious material, keeps a nearly constant meaning, is not determined by individual factors alone, and has parallels in myth, cult and religion. The symbols run into thousands, but the ideas they stand for are few: the bodily self, the closest relatives, and birth, love and death. Against Jung, he argued that symbols are recreated by each individual rather than inherited ready-made. His touchstone was that only what is repressed is symbolised, and only the repressed needs to be. On these grounds he rejected the "functional" and "anagogic" readings of Herbert Silberer and Jung, which take abstract tendencies for the meaning of a symbol; in his view they diluted the concept and, in treatment, often served resistance. In metaphor, he concluded, feeling is over-sublimated; in the true symbol it is under-sublimated.
The Early Development of Female Sexuality4, read at the Innsbruck Congress on 1 September 1927, opened by endorsing Horney's warning that analytic views of early female development were distorted by bias. Jones suggested that male analysts had taken an unduly phallocentric view that underrated the female organs. He argued that castration is only a partial threat, and proposed the name aphanisis for the total and permanent extinction of the capacity and opportunity for sexual enjoyment. This, he held, is the fundamental dread of both sexes and underlies all the neuroses; in this way he recast the castration complex as one special case of a wider fear. The sexes differ in how they imagine aphanisis: the boy as castration, the girl, more dependent on her partner, as separation and desertion. Drawing on Klein's analyses, he described direct transitions from the oral stage to the Oedipal situation in girls. He distinguished a pre-Oedipal from a post-Oedipal penis envy, the latter a regressive defence against the privation of the girl's incestuous wishes. He also suggested that the phallic phase Freud described in girls was a secondary, defensive formation rather than a true developmental stage. The same paper proposed that guilt and the super-ego are built up from within, to protect the child from the stress of ungratified libido, and that the child exploits external disapproval rather than simply submitting to it.
Though he remained loyal to Freud, Jones differed from him on female sexuality, on lay analysis, on telepathy and on the merits of Klein's work. In the biography he was sceptical of the death drive but valued Inhibitions, Symptoms and Anxiety and Freud's later theory of the ego (The Life and Work of Sigmund Freud1).