Carl Jung (1875-1961) shares with Sigmund Freud, his mentor then his despised rival, the signal achievement of worldwide fame and an adjectival existence.

Thus “Jungian” analytical psychologists continue to glare across the muddy no man’s land of the psyche at the fixated complexes of “Freudian” psychoanalysis. Both sides have held the worried masses of the 20th century in thrall to their apparently profound theories of human development. Freud created libido, the Oedipus theory, transference, denial, and a host of other troubling concepts. Jung, a Swiss pastor’s precocious son (although notoriously poor at maths, intermittently school phobic, and teased as “the barrel” by fellow students) dreamed up archetypes, individuation, and the collective unconscious.

Wrapped in notions of synchronicity, quaternity (he regarded four as the magical-mystical number par excellence), and alchemical formulation, he conceived of the influential extravertintrovert theory of personality (Psychological Types was published in 1921) but increasingly slid into mysticism. Given that he also wrote exhaustively, recording every last nuance of his dreams and ideas (his Memories, Dreams, Reflections was published posthumously in 1963), what is there left to say?

This new biography is detailed, in terms of its notes and index, and a bibliography of more than 440 books. One cannot gainsay Frank McLynn’s achievement in summarising such a mass of material in just over 500 pages, not least because making sense of Jung’s complex theories has baffled most modern psychiatrists. In fact, the history of the psychoanalytic movement in general, viewed from the sceptical nineties, is strangely similar to the history of the early church with its schisms. The complex arguments (for instance, the seduction fantasy) still active among historians, and the “irony of excessive secretiveness among depth psychologists” with their closely guarded archives, tend to dominate the picture. In fact “who slept with who?” (and Jung, as well as many of Freud’s disciples, was a notorious womaniser, as often as not with patients, and destroyed numerous love letters in his terminal months so as to cover his tracks) has become more interesting than “who thought of what?” They were also not very nice to each other. When Jung broke with Freud in around 1910-11, Freud decided Jung was “crazy”. After Freud’s death, in 1939, Jung was persistent in his belief that Freud’s “unacknowledged neurosis was the root of all evil in psychoanalysis”. The concomitant despair of many of their followers (generating a string of suicides) and Jung’s constant breaking of friendships with men (women clung to him in droves) was thematic of both his life and the whole enterprise; and of course there is the Teuton v Jew undercurrent.

Perhaps least satisfactory in McLynn’s version, however, is the author’s own engulfment in psychoanalytical (or analytical psychological) modes of thinking. While being nicely critical of Jung’s often appalling behaviour - for example, the great man often walked out on patients in mid session because they bored him, yet readily journeyed to the USA at the drop of a hat if summoned by a millionaire neurotic - McLynn can’t resist outlining dream after dream and trying to understand them in Jungian terms. And since most of the background notes relate to Jung’s own writing, it is hard to know how many of the odd coincidences that plagued his life actually happened. Thus Jung’s version of various events tends to change over time, and the pastor who spoke over his grave regarded him “as a prophet who had stemmed the tide of rationalism”.

Yet rational explanations do not seem to be the author’s chosen path. For example, Jung we are told tended to laugh loudly at “remarks and jokes that were not all that good”. McLynn then posits “the true explanation” for this habit as “overcompensation, masking the anger he really felt”, yet 200 pages later admits that this style of analysis can validate just about any proposition whatsoever. He in fact criticises Jung for his reversion to his “enantiodromia” (that is, declaring a behaviour or statement to be the opposite of its overt meaning), so it is not surprising that he also himself lapses into forms of verbal quagmire. For example: “more correctly, what he did was to correlate the functions of sensation and intuition with, respectively, the object-entranced extravert and the subjective introvert, and then derived thinking and feeling from intuition and sensation, with consequent problems for the alleged quaternity”.

Notwithstanding these muddier divertissements, the picture that emerges is quite extraordinary. Because Jung not only spent hours reading and noting obscure documents, as well as analysing numerous patients, and travelling widely, and eating like a “trencherman” and womanising cruelly, but he also (unlike Freud) worked in an asylum. Using the technique of word-association he attempted to unravel the mysteries of dementia praecox,an illness later termed schizophrenia. Furthermore, between about 1913 and 1918 Jung reckoned he had warded off an impending psychosis, in that he found himself dominated by various inner voices, spent hours writing down what they had to say amidst his symbolic dreams, and (apparently) explored the dark depths of his unconscious.

From this experience he eventually derived his notion of the collective unconscious as “a sea upon which the ego rides as a ship”. And it has in fact become accepted, by most authors and by McLynn, that Jung in some way did go mad, but somehow cured himself by bravely working through the process, his self cure being the event that triggered his own complex theory of salvation via individuation. From this valley of psychosis he then climbed to the heights of counter-Freudian fame and the theological expansions, as the guru of the 1950s and the icon of the 1960s. Armed with his own theory he could even attribute his “polygamous tendencies” to “a deep well of rage” at his unreliable (because she was mentally ill) mother.

But even this evidence is too self-serving. Jung’s so called illness has no objective record. In fact he continued lecturing, seeing patients, and, as part of his Swiss military service in World War I, he would be a successful commandant of a large holding camp full of Allied prisoners of war. Perhaps more germane to his description of his state of mind was the fact that he was forcing his extremely wealthy wife to accept a menage a trois with his mistress, Toni Wolff, and he also needed, urgently, to create a new philosophy having broken with Freud. It is not surprising, given his overweening pride and sense of destiny, that he was therefore busy and a bit troubled. Yet this simpler analysis constantly gets blocked in McLynn’s adherence to the complex trails of Jungian exegesis.

Perhaps McLynn should have written two books in one, outlining the core narrative in italics so allowing the lay reader to skip the longeurs of Jungian dreamtalk. We note with glazed brains Jung’s use of “the alchemytransference analogy as an established item in the science of psychology”, but thrill at his viewing, at the age of eight, in his father’s arms, the celestial effects of the Krakatoa explosion in 1883. We wonder at the gobbledegook about archetypes and alchemy, yet warm to a man who can cheat at patience. And how seriously should one view a man who believed jet lag to be due to the body going too fast for the soul?

Trevor Turner is consultant psychiatrist at St Bartholomew’s Hospital, London