He is best known for his “Human Birth Theory” which aims to define the roots and causes of mental illness in order to propose a structure for diagnosis and psychotherapeutic cure.

In 1957 Fagioli worked at psychiatric hospitals in Venice, where he was soon disappointed by the organicist practice, a methodology directly inherited from 19th century psychiatry.

Since its early years, this form of psychotherapeutic group drew the attention of the media,[10] due in particular to Fagioli harsh criticism towards Sigmund Freud.

In response to this command, in November 1980 Fagioli decided to leave the university and carry on the Analisi Collettiva sessions in his own private studio in Via di Roma Libera 23, in the Roman neighbourhood Trastevere.

In the same year, a book based on an interview with Fagioli, “Child, Woman and Man’s Transformation” ("Bambino, donna e trasformazione dell'uomo") was published.

[14] A few years later, The Conviction became a subject of great controversy, being defined by the media as an apology of rape,[15] but both Fagioli and Bellocchio[16] responded in defence of their work.

In addition to his work with Marco Bellocchio, in 1997 Massimo Fagioli wrote, directed and produced the soundtrack of the film Il cielo della luna.

[20] This project appeared in different volumes of selected works such as “Rome’s Wonders: from the Renaissance to the present day” ("Le meraviglie di Roma: dal Rinascimento ai giorni nostri") realised by Vittorio Sgarbi.

[21] However, amongst his architectural projects, “The Fountain” ("La Fontana"), built in Largo Ettore Rolli for the neighbourhood urban renewal, gained less recognition.

Due to the lack of maintenance required for water monuments, the fountain was criticised by some experts - among them the art critic Vittorio Sgarbi himself and some of the area's inhabitants.

In 1975 he gave a lecture on Das Kapital by Karl Marx at the University of Siena, whilst between the years 1979 and 1981 he collaborated both with the Italian Communist Party and with Lotta Continua newspaper.

[27][28] Later on, Fagioli came in touch with the Italian Radical Party, through the periodical Quaderni Radicali and more specifically and personally with Marco Pannella and Emma Bonino.

During the foetus’ passage from the dark intrauterine environment to the light of the external world, a retinal photo-stimulation determines the activation of the brain.

[35] The paper “Conical intersection dynamics of the primary photoisomerization event in vision” published in Nature in 2010 highlighted that retinal-light contact triggers a specific chemical-brain reaction.

In regards to this point, Fagioli observed the newborn physical condition in the first instants of life; a span of time around 20 seconds long when the baby is not breathing, the body has no muscle tensions and has apparently no reaction towards the external environment.

[38] In his first theoretical book, Fagioli stated that in the passage from a dark and warm condition into the coldness of the external world, light is the “absolutely new stimuli”.

Fagioli postulated that light stimulation determines simultaneously the beginning of human thought activity and the emergence of what he formulated as the annulment pulsion of the non-material world.

[41] In his book "Death Instinct and Knowledge" this complex dynamic is expressed using the terms “disappearance fantasy”, a syntagm that summarises his research on human birth, as Fagioli stated in the article “Twenty-one words that did not exist before” published on Left.

[47] Fagioli thought that the possibility to cure mental illness is achievable only by knowing, interpreting and overcoming non-conscious dynamics experienced in “pathological” human relationships.

This belief can be found in the Freudian Es, a phylogenetic heritage criticized by Fagioli as a restatement of the Original Sin, codified by the Judeo-Christian-Islamic tradition.

[52] He stated that if this alteration is expressed on a conscious level, it can be curable only through a psychotherapy founded on three fundamental points : setting, transfer and interpretation.