Curiosity implies a desire to know. But what is curiosity for? Is curiosity always for some use, does it anticipate to utilize the knowledge that it will get, or is there something like a pure curiosity, a “curiosity for the sake of curiosity” (e.g. “scientific curiosity”)? According to Freud, curiosity does not appear in a pure state, instead a “vital exigency” has instigated the curiosity:
At the instigation of these feelings and worries [about losing the parents’ care to the newborn sibling], the child now comes to be occupied with the first, grand problem of life and asks himself the question: “Where do babies come from?” – a question which, there can be no doubt, first ran: “Where did this particular, intruding baby come from?” We seem to hear the echoes of this first riddle in innumerable riddles of myth and legend. The question itself is, like all research, the product of a vital exigency, as though thinking were entrusted with the task of preventing the recurrence of such dreaded events. Let us assume, however, that the child’s thinking soon becomes independent of this instigation, and henceforward goes on operating as a self-sustained instinct for research. (Sigmund Freud, 1908, On the Sexual Theories of Children)
In the last sentence, with the reader’s permission, Freud assumes that the drive to know splits from the vital exigency at its origin and purifies itself. This additional assumption that intervenes from outside the thoughts that flow through the previous sentences is in fact instigated by another “vital exigency” that belongs to the person of Freud: It originates from Freud’s attachment to the concept of “scientific curiosity”. The additional assumption in the last sentence is necessitated by Freud’s authorization of the discipline of psychoanalysis that he founded via the concept of “science”. Here Freud would like to indicate that the motivated curiosity of the child that is envious of its sibling is merely a relative curiosity due to being attached to a certain “vital exigency”, but in order to indicate this relativity he is compelled to assume the possibility of a pure and absolute “scientific curiosity” (“instinct for research”). However “scientific curiosity” is as relative as the curiosity of the envious child because it’s attached to the “vital exigencies” of scientific authorization. Many years later, Lacan would call this power of knowledge that conceals its real interlocutors “University discourse” .
In contrast to Freud, Lacan is suspicious of curiosity. Lacan’s three fundamental passions are the passion of love, the passion of hate and the passion of ignorance . The passion of ignorance expresses Freud’s concept of “repression”: The subject represses some stuff about sexuality and aggression; (s)he does not want to know, (s)he ignores, forgets, pushes away, dismisses. But this repressed content returns under various forms, and these forms are the symptoms that manifest in the subject. According to Lacan, there is no “desire to know” or “drive to know”, there is only a drive not to know, there is instead a horror of knowing . Thus the “curiosity” that emerges in the subject should be understood as the side-effect and symptom of an underlying incuriosity.
There cannot be anything like a “pure scientific curiosity” to motivate the psychoanalyst. So we are unable to oppose an Absolute Curiosity to the daily relative curiosities; all curiosities are relative and are instigated by determinate “vital exigencies” that belong to the persons. This instigation need not be pathological as in the example of the envious child, but the exigency that instigates the curiosity is always the purpose of authorization . In most examples, the curious person imagines to be taken as an interlocutor due to the knowledge (s)he obtains. On the other hand, one cannot say that the curiosity consciously anticipates a utility, because the exigency that instigates the curiosity is unconscious. Like anyone else, the psychoanalyst has repressed some stuff into the unconscious and these have returned in the form of symptoms. What matters is the analyst’s recognition of the symptom of his/her own ignorance:
Indeed, the analyst cannot follow [the path of training] unless he recognizes in his own knowledge the symptom of his own ignorance, in the properly analytic sense that the symptom is the return of the repressed in a compromise [formation] and that repression, here as elsewhere, constitutes the censorship of truth. Ignorance must not, in fact, be understood here as an absence of knowledge but, just as much as love and hate, as a passion for being—for it can, like them, be a path by which being forms.
This is clearly the passion that must give meaning to all of analytic training, as is obvious if one simply allows oneself to see that this passion structures the analytic situation…
The positive fruit of the revelation of ignorance is nonknowledge, which is not a negation of knowledge but rather its most elaborate form. The candidate’s training cannot be completed without some action on the part of the master or masters who train him in this nonknowledge—failing which he will never be anything more than a robotic analyst. (Lacan, Écrits, p. 297)
The operation that is implied by “some action in nonknowledge” is the placing of truth in the horizon of knowledge. The censoring of truth by repression does not destroy truth, it does not neutralize truth, it rather places it on the horizon of knowledge . The “lines of flight” (Deleuze & Guattari) that emerge on the horizon of truth is a side-effect of the censorship operated by the passion of ignorance. Nonknowledge implies the awareness of this effect .
 Jacques-Alain Miller: “Lacan said ‘there is no desire to know, there is no drive to know.’ And he added: ‘the only thing I have ever discovered in a patient, and in myself, is the drive not to know.’” / Jacques Lacan, 21st Seminar: “well I hope you remember, not only did I emphasize this, that there is no desire to know [désir de savoir], but that I even talked about something like … that I actually articulated this horror of knowing [l’horreur de savoir]. There you go!”
 The counterpart of authorization by exigency is the embodiment by enjoyment, see “The Dialectic of Castration and Jouissance”