INFPs have extroverted Thinking (Te) as our inferior function.
Te is loosely characterised as pragmatic, goal oriented, and efficient.
This might sound like the very opposite of an INFP, and indeed when we try to use our inferior function we usually do so in a comparatively rudimentary way.
By contrast, introverted Thinking (Ti) is usually depicted as more of an observational, big picture, theoretical modelling of how things work.
If Te wants to get things done, Ti wants to understand how and why things work.
Ti dominant types are INTP and ISTP, while ENTP and ESTP have Ti in their auxiliary (second) position.
Jung on introverted Thinking
Ti is often presented as highly objective, but Jung demurred, stating that:
External facts are not the aim and origin of this thinking, although the introvert would often like to make it so appear. It begins in the subject, and returns to the subject, although it may undertake the widest flights into the territory of the real and the actual.
Hence, in the statement of new facts, its chief value is indirect, because new views rather than the perception of new facts are its main concern.
It formulates questions and creates theories; it opens up prospects and yields insight, but in the presence of facts it exhibits a reserved demeanour. As illustrative examples they have their value, but they must not prevail. Facts are collected as evidence or examples for a theory, but never for their own sake…
For this kind of thinking facts are of secondary importance; what, apparently, is of absolutely paramount importance is the development and presentation of the subjective idea, that primordial symbolical image standing more or less darkly before the inner vision.
Its aim, therefore, is never concerned with an intellectual reconstruction of concrete actuality, but with the shaping of that dim image into a resplendent idea.
Its desire is to reach reality; its goal is to see how external facts fit into, and fulfil, the framework of the idea; its actual creative power is proved by the fact that this thinking can also create that idea which, though not present in the external facts, is yet the most suitable, abstract expression of them.
Its task is accomplished when the idea it has fashioned seems to emerge so inevitably from the external facts that they actually prove its validity.
Strangely, I can relate to this. For a long time I was inspired by the thought of understanding the true nature of reality, and I sensed these “primordial images” and sought to describe and define them.
It’s said that male INFPs often mis-type themselves as INTPs (but not the other way around). I think this is because “Feeling” is regarded as subjective and feminine, and therefore we are encouraged and conditioned to always explain, rationalise, and justify what we sense through feeling, and strive to be objective and aloof in our beliefs and opinions.
What introverted Feeling and introverted Thinking have in common, according to Jung, is that they are both subjective, and both oriented toward “primordial images”.
This is the introverted aspect of either function – users of Ti and Fi are both excited by this inner image dimly perceived or felt. Both wish to bring that image into the light or into life, but Ti apprehends it conceptually and logically, while Fi apprehends it by feeling.
Happiness for Ti-users
Presumably Ti plays an analogous role in INTPs and ISTPs as Fi does in INFPs.
Jung states that Ti has a kind of inner, subjective direction to it that Te doesn’t have. He contrasts Darwin and Kant:
Just as Darwin might possibly represent the normal extraverted thinking type, so we might point to Kant as a counter-example of the normal introverted thinking type. The former speaks with facts; the latter appeals to the subjective factor. Darwin ranges over the wide fields of objective facts, while Kant restricts himself to a critique of knowledge in general.
This subjective direction must be conceptual rather than feeling-based as it is for Fi, so I imagine that Ti users feel a kind of pull towards an underlying conceptual reality behind things.
If I can find the feeling-image of a library, a Ti-user can find the conceptual-image of a library, and perhaps be in a better position to communicate his image than I am mine.
I can’t describe the feel of a library, though I might describe the sensory details and circumstances of a library that feels right to me.
But a Ti-user might very well say that a library is conceptually an information-sharing system, or a way of offsetting the cost of books, or part of a government interest in public education, or…possibly all of the above, and individual Ti-users might bring to the subject their own conceptual priorities.
Can an INFP use Ti?
In theory, an INFP using Ti is bizarre and improbable. Ti is said to be a “shadow-function” for INFPs. Shadow functions are deeply unconscious and inaccessible, but still play some role in our experience of life.
Still, it seems unlikely that I’ve actually been using Ti in the past, even if it felt like that at times.
What’s more likely is that a learned distrust of Fi, coupled with a study of Philosophy, encouraged me to restrict my expression of Fi to more abstract, conceptual and objective forms.
Philosophy enforces logical and analytical thinking; but it’s also true that my enjoyment of philosophy was limited. It never fully satisfied me even though I was shaped by it, and following things conceptually without an accompanying positive feeling leaves me exhausted and miserable.
In hindsight, I probably used (and endured) Philosophy to the extent that it mirrored the feeling-images I already possessed.
Talking to genuine Ti-users makes it clear that my perspective is a lot “fuzzier” and feeling-oriented than theirs. I might be able to describe some of my feeling-images in conceptual terms, but its rarely worth the effort because it still feels as though communication has been unsuccessful.
Which makes sense, doesn’t it? Because what I’m trying to communicate is not really the conceptual aspect of these images, but the feeling. You can’t translate feeling into concept.
With other Fi-users, communication is about pointing to a particular feeling-image. But non-Fi-users will always see things differently.