Andy:
On Lacan, first of all - just to make sure we're on the same page.
The unconscious/id in Lacan is the signified, the ego is the Ideal I and the superego is the symbolic order (signifiers). Of course, the ego itself - the Ideal I - is also a signifier rather than the signified. It seems to me that Lacan is saying we necessarily leave something behind when we make the transition from animal instincts to socialised beings - we must forget the real in order to create language, which from then on defines us, our viewpoint and even the way we see things in a literal way (i.e. blue is only blue because we've decided it is - other languages don't have a word for blue because it does't exist). So our literal experience of life is commanded by language and is always removed from the "real" or signified. The lack is an awareness that there is something missing (because we are separated from the real/signified at all points) but it is impossible for us to get there and remain human. I think Lacan also considered it folly to try - he said something that to me seemed a little short about the surrealists
But love their films as much as I do, the surrealists were doing something I couldn't give too much of a shit about - leaving ideology, being authentically themselves, returning to the purity of their identity blah de blah de blah - not only impossible but slightly irritating and definitely pointless. (Though I like the art and films - just not their philosophy). This, incidentally, was what I thought of when I read about Fi.
I'm trying to fit Ni into this for myself. I had always considered Ni to be an awareness of the process of signification and a rejection of the signified. I.e. - nothing has meaning, because it is not possibly to reach the signified (something that is real). This is a problem I had with Ti. People describe it as a search for meaning. For me, it is a search for rationalisation - which means meaning but in a different way. I think in more of a "what is the meaning of this?" way than a "this means...symbolically" - that would be the opposite of me. I don't tend to see meaning in the things around me. I tend to see what is there and why it's there and why it's arbitrary - as you say (and your view is very close to what I thought Ni was, though I'm not sure it's the same). I don't actually find personalised meaning in things - like others seem to. "This means so and so to me because..." - you know, when someone has a souvenir or something. Or this song means so and so to me.... I don't really do that. And I had considered it to be because I tend to see meaning as arbitrarily ascribed. That's not to see that we should not believe anything. It is to say we should believe in the values that, considering the arbitrariness of it all, works out best - sort of knowing this is arbitrary but it;s not like there's any other way to live and I am not offended by it's arbitrariness - it's just how it is and you go with it because that's what works. That's not to say I believe there should be no change, it's just change within the system seeing as we cannot change the system, regardless of what external objects we move around.
So yeah. I would relate Ni to a knowledge of the signification of things (or that system that always already signifies but arbitrarily so) rather than being in the unconscious in the same way that the signified is in the unconscious. Lacan said, and I agree to a certain extent, that our signifier-filled conscious is born of the signified in our unconscious but the signified is inaccessible - which makes theoretical sense, but I don't know how useful it is.
Now, you mentioned deconstruction. Funny that, because when I first came to my conclusion about Ni (I don't know when or what I'd read, sorry) it struck me as the process of deconstruction. Again, to make sure we're on the same page, I am assuming you mean deconstruction as Derrida described it? Rather than conscious deconstruction (deconstructing a joke, say - that's more like self-reflexivity). Derrida said that the system of signification is always already deconstructing itself - that it is always dissolving even as it is created, in that it is not possible for it to exist. So, because "absent" can only exist if the concept of "present" exists (because otherwise we would not have a name for it - seeing as there would be nothing to compare it with) then there must be a "trace" of something between the two words that is neither present nor absent but the root at which we are able to think - simultaneously - "absence" and "presence". Now, this works for me better than Lacan. Because I would think of Ni as being, not the trace itself (which would be impossible) but an awareness of the trace - an awareness of the system of signifiers around us. This also fed in, for me, to the idea that Ni will pick up on what I considered to be "surface signifiers" without needing them to be signifying anything at all. So. Let's say you see a picture of someone with their arms crossed and another person with their arms open. It is not that arms crossed MEANS angry/defensive whatever or that arms open MEANS welcoming/warm whatever - those two signifiers do not mean anything in and of themselves (although obviously there's a psychological and socialisation aspect) because it depends on what signifiers they are being presented alongside. If the person with the arms crossed is smiling, perhaps they are nervous or cold. If the person with the arms open is laughing in a certain way or is holding their face in a certain way, this would actually be read as domineering. So the signifiers themselves do not have meaning, their meaning is ascribed in and of the moment - according to what they coincide with.
I'm not saying Ni users literally go through all that in their mind, by the way. They're not sitting there working out the puzzle (like the Sherlock Holmes references you sometimes gets about INFJs - he uses Te, I believe). The reading people thing was an example of a different viewpoint, but I don't believe Ni users would sit there thinking about it.
So that's what I was thinking of with regardless to (post)structuralist reasoning (which had crossed my mind too, I'm glad you mentioned it).
so, how do you INFJs relate to what thomson says? do you recognize yourself in her description of Ni? if not, why do you think you're INFJ?
As for that - I don't know. I find it difficult to say exactly what I'm like or what I do. 90 per cent of the time I say "I'm like..." I'm wrong and someone points the inconsistencies out to me at some point. I do not have a satisfactory narrative for myself but I don't think it's necessary.
EDIT: The only people I have seemed to agree with a lot about Ni have been INTJs - I've seen some bang on descriptions from them on what I thought I recognised in myself. Which does not mean it is Ni. It could be that they describe tertiary Fi or that they are describing the working of Ni with Te, for instance.
EDIT II: Another point I forgot to mention that I would like to discuss with people who have opinions on Ni. I have heard from some people that Ni takes time to order itself so that you get the "aha" moment rather than conscious thought. Now. I don't do conscious thought when making decisions but the "aha" moment tends to be immediate sometimes (depending on the subject). With people, for instance, I know instantly. But I think the difference between gut reaction and emotion does need to be made clear - as someone said below - that it is not that I have a feeling about the person - I more have the sense of having figured them out and I do judge from there in a relatively passive way.
But I would like to know why people feel Ni takes time. It isn't a challenge. I just haven't figured that out yet.