Noli me tangere, meaning "don't touch me," is the Latin version of words spoken, according to John 20:17, by Jesus to Mary Magdalene after his resurrection. The original phrase, Μή μου ἅπτου, in the Gospel of John, is better represented in translation as "stop clinging to me."
The touch-me-not suggests the tendency to "cling to," i.e. mourn, dead ideas etc. But when does remembrance (narcissistic object-identification) become fixation (disavowal of an object) [see below on Freud]? Assuming a preference for embodied cognition, perhaps when it ceases to be bodily/affective, when it becomes transfigured into something merely mental/ideal. [= the not]
But does that eliminate faith, which keeps alive a dead idea, or does it just capture the tendency of remembrance to fix a thing to identify it? Or are there just better and worse ways to remember something: recollection, nostalgia, worship, obsession, forgetting (that is not forgetting), etc.?
Or maybe the touch-me-not is actually an injunction from the Father, suggesting that the idea etc. in medias res of its transfiguration is off limits, especially to embodied cognition [= the not-yet] . . .
Or maybe it suggests (reality-)testing the idea etc. by taking it out to your "brethren," rather than dwelling on it in isolation [= the yet] . . .
John 20:17: "Jesus saith unto her, Touch me not; for I am not yet ascended to my Father: but go to my brethren, and say unto them, I ascend unto my Father, and your Father; and to my God, and your God."
Freud, "Mourning and Melancholia": Mourning is characterised by a loss of interest in the outside world, melancholy by a(n apparently unjustified) loss of self-esteem: "In mourning the world has become impoverished and empty, during melancholia, it is the ego itself [kenosis: the 'self-emptying' of one's own will and becoming entirely receptive to God]" (246). However, the melancholic loss of self-esteem is actually directed at the love object itself. The subject, instead of withdrawing cathexis from the object, unconsciously identifies with the now-hated object to which he or she remains ever more firmly attached.
[identification:] O loved → O identified with, thus S = O [= regression]
→ [abandonment: ] O lost, thus S lost [= ambivalent choice]
→ [disavowal:] O hated [sadism], thus S hated [masochism]
This pathological development stems on the one hand from the narcissistic nature of the initial object choice, which by its nature promotes narcissistic regression, and on the other hand from the ambivalence of the choice and the predominance in it of the sadistic impulse, which here assumes masochistic form.
But in melancholia as in mourning, it is essentially the work consisting in finishing with the object (by degrading it or declaring it dead) that will "strike dead" the dead and release the subject.
(Sigmund Freud, "Trauer und Melancholie," Intern. Zschr. ärztl. Psychoanal 4 : 277-287; G.W. 10, 428-448; "Mourning and Melancholia," SE 14 [1916-1917g]: 243-258)