Another eccentric french scientist, Jean-Pierre Petit, was one of his rare visitor (they shared the same antimilitarist views, and became friend after his exile).

He wrote a brief story about the context of his withdrawal away from society:

https://www.jp-petit.org/Nouvelles/Grothendieck.htm

https://pastebin.com/7y2pbsMb (the translation)

Focusing on his "crackpot beliefs"

https://webusers.imj-prg.fr/~leila.schneps/grothendieckcircl...

This chapter expresses the meaning and the importance of dreams and the author’s empirical conviction that dreams are sent by an outside force, called “le Rêveur”, who knows each of us intimately and sends dreams in order for each of us to know himself fully. Although all dreams are message, he signals the existence of particularly powerful ones which should act as a call, and warns against the inertia (fear of change) which prevents the dreamer from the meaning contained in it.

The question “where do dreams come from” is essential here. Grothendieck examines notions that our languages contain about “gifts”, or the expressions “ajouter foi” or “Glauben schenken” which indicate that our languages actually contain the idea that things come to us from some outside source. He describes how he himself wondered what part of dreams come from outside (as gifts) and what part from reflexes of our own psyches, impulses etc. He anticipates by telling us that he reached the final conclusion that dreams are entirely and completely messages sent to us by the Dreamer to indicate fundamental truths about ourselves (which we may ignore or not as we wish).

Full text in french: http://cm2vivi2002.free.fr/AG-biblio/AG-clesonges.pdf

Voevodsky's last interview

In 2006-2007 a lot of external and internal events happened to me, after which my point of view on the questions of the "supernatural" has changed significantly. What happened to me during these years, perhaps, can be compared most closely to what happened to Karl Jung in 1913-14. Jung called it "confrontation with the unconscious". I do not know what to call it, but I can describe it in a few words. Remaining more or less normal, apart from the fact that I was trying to discuss what was happening to me with people whom I should not have discussed with, I had in a few months acquired a very considerable experience of visions, voices, periods when parts of my body did not obey me and a lot of incredible accidents. The most intense period was in mid-April 2007 when I spent 9 days (7 of them in the Mormon capital of Salt Lake City), never falling asleep for all these days.

[...]

I did not go crazy, although sometimes there were "drifts" when I began to seriously believe in this or that "theory". As a rule, these drifts straightened quickly, usually in a few hours. More serious were periods of hopelessness. In such periods, the idea that it is necessary to continue fighting is very helpful, because from this, albeit to a small extent, depends in which spiritual world today's children will live.

[...]

- You said that you were offered pictures of the world. And, as far as I understand, it all evolved that it was a metaphysical scam. You broke through the layers of "explanations", realizing that certain manipulations with consciousness are taking place, that someone is building up whole philosophical systems inside you, and this happens as an invasion from the outside. So? - It is difficult to build a real philosophical system solely on the basis of external influences. From the outside (not understandable to me by the way) come "seeds" short ideas, associations, etc. In the vast majority of cases, what of these seeds grows, if they are allowed to grow freely, is useless or harmful. Somehow I sounded for such systems the interesting name "harness". Those. what can be used later to direct human behavior. Whether a person allows these seeds to grow or quickly culls depends largely on their skills of working with their inner world. The problem is aggravated by the fact that sometimes the appearance of such "seeds" is accompanied by other phenomena, not of a mental, but of an emotional or even real plan, which seem to confirm the system that is starting to form. Another important property of these seeds and growing systems is that they, as a rule, contain, especially at the initial stage, really true and interesting ideas. The transition from the truth to the lies in these systems is often difficult to notice. A person develops an instinctive confidence in the emerging thought stream, then he begins to believe in its continuation which is already false, and then it is difficult for him to admit to himself that he believed in bullshit and he begins to deceive himself just to not feel fools. Often systems are built in such a way that starting from a certain level of growth, they support themselves also through fear.

This is reminescent of Saussure (the linguist), who held the notion of identity in a way that is reminescent of the univalence axiom:

http://www.revue-texto.net/docannexe/file/116/saussure255_6....

He delved into rather esoteric topics too.
https://journals.openedition.org/linx/671

The anagrammatic nature of the research: words under words

Here we must start with an example. They abound. I will take one more or less at random. It is again a Saturnian verse. It is extracted from a particularly archaic text, a "vaticinium" - "oracle" - which, according to tradition, dates back to the beginning of the 4th century BC, precisely to the year 396. It is a response addressed to the Romans by the oracle of Delphi, at the end of the interminable siege of the Etruscan city of Veii: the god Apollo announces the Romans' victory, and demands the offerings that are due to him. This "vaticinium" is quoted, three and a half centuries later, by Livy, in a modernized form. Saussure, an excellent connoisseur of Latin history, restores one form to the oracle that he believes is closer to the one it had in 396. One of the verses > has, in this reconstructed archaic Latin, the following form:

DONOM AMPLOM VICTOR AD MEA TEMPLA PORTATO

("Let the victorious [general] bring an important offering to my temples")

Saussure successively analyzes each of the two hemistichs of this Saturnian verse. He observes that the phonemes of each of these two hemistichs repeat the phonemes of the name of the god APOLLO, in the nominative case, and in its archaic form, with only one > -L-.

First hemistich:
donom AmPLOm victOr
A PLO O

Second hemistich:
ad meA temPLa pOrtatO
A PL O O

Thus, although the name of the god is absent in its complete linear form in each of the two hemistichs of the verse, it is nevertheless present through each of its phonemes. I would like to draw attention to an extremely frequent phenomenon, which poses heavy difficulties for Saussure: the phonemes of the anagrammatized name (the "theme," then the "word-theme," sometimes rivalled by "word-type" in Saussure's terminology) appear on the surface of the verse in disorder. I will come back to this problem in part 7, > specifically devoted to questioning the linear nature of the signifier.

[...]

To find linguistic elements belonging to other grammatical classes, one must turn to less frequent cases: cases where the "cryptogram" - that's the name given to it in this case - takes the form of what I call a micronarrative. The most spectacular case is that of the "vaticinium" reported by Livy, which has already been studied from another point of view in part 3. This "vaticinium" spans eleven Saturnian verses, as we have seen before, and therefore quite long: from about twelve to fifteen syllables. This set of verses, totaling about a hundred syllables, contains as a cryptogram a narrative > obviously much briefer than Saussure restores as follows:

Ave Camille
Ave Marce Fouri
Emperator
Dictator ex Veieis
Triump(h)abis.
Oracolom Putias Delp(h)icas (Starobinski, p. 78)

I translate this archaic Latin, both phonetically and morphologically:

"Greetings, Camillus, greetings, Marcus Furius, commander-in-chief. As dictator following your victory at Veii, you will triumph. Such is the oracle of the Pythia of > Delphi."

This is what I call a micronarrative. It necessarily includes words from several linguistic classes: proper nouns and common nouns, as we have already encountered, but also a verb conjugated in a personal form (triump(h)abis), an adjective (Delp(h)icas), a > preposition (ex), and the interjection ave.