This is an attempt to synthesize and condense the functional profile of the INFP to be legible, comprehensible, and adequately informative.
Let the following be known:
Fi and Te are judging (read: evaluating) functions, while Ne and Si are perceiving (read: data-collecting) functions. INFP's generally utilize all four functions (as well as their shadows, but those are irrelevant to this piece), but the order of development is Fi, then Ne, then Si, then Te.
Dominant Introverted Feeling (Fi)
The crux of the INFP lies primarily in the judging function, Fi, which concerns itself with the subjective self-identity. The data and information the individual receives is filtered through the mechanism, Fi, and evaluated, subject to such questions as: who am I?; who are they (as distinct from the concept of self)?; what is my purpose and meaning in life?; what do I want?; where am I going with this?; what is morally right or wrong according to my beliefs?
If outsiders were somehow capable of observing this introverted, judging process, they might find it inherently at fault since objective, tangible measurements and means through which this function evaluates are generally nonexistent. Indeed, the manifestation of the INFP often has a complete disregard for or contradicts what others might perceive as apparent truth and rightness, birthing the idea of the societal pariah.
In the pursuit of spiritual and often, quite synonymously, moral perfection, there must be an intrinsic faith in humanity - faith that the INFP, who is as human as any other person, will empathically extend his or her knowledge and comprehension of the self unto others. There is often the idea of a tragic undercurrent permeating from the INFP individual, which is plausible when considering the quandary he or she is perpetually submerged in: in order to understand and grasp the Light, one must be similarly conscious of and capable of wielding the Darkness within. Good cannot exist without the concept of evil. When considering this, the outsiders' fears of the dominantly Fi individual are not unjustified - the INFP is familiar with every nook and cranny, every facet of the human psyche concerning emotionality to the extent that one could certainly be apprehensive of the potential for the manipulation and penetrating truths a corrupted INFP might subject others to.
Then it must be trusted that the essence of the INFP shares some fundamental sense of kinship with others. As Feeling seeks harmony, so too must the INFP see himself or herself as a part of humanity, seeking harmony in external relationships; although Fi is concerned primarily with the self, with a spiritual sense of synchronization the collective human race might be grouped under the bastion of equanimity.
Auxiliary Extroverted iNtuition (Ne)
Although certainly to be thought of as whimsical, the INFP is, in some respect, grounded by the superior Fi function as compared to the flighty ENFP or ENTP. Still, a supportive Ne comes viscerally, grasping at arbitrary points in an expansive pool of possibilities. The truth will be tangentially stretched.
The INFP often fancies that he or she is an original romantic, but truly Ne is an unoriginal perceiving function since it collects data which already existed (thus the idea that Ne is tangential and web-like is seen). Ne merely picks and chooses on a whim. Nonetheless, the variance by which Ne grasps data and Fi filters the data invariably causes the manifesting persona to appear an iconoclast in the eyes of many.
The Ne whims, again, are centralized by Fi, which ultimately synthesizes and interprets what data is accumulated. In the course of perceiving and data-collecting, Fi will compel the INFP to, in response, choose to react, withdraw, or perhaps delve further before passing judgment depending on the scenario and the unique individual.
To clarify, a reaction is a premature judgment or one which has already been contemplated and finalized in its consideration beforehand, or at least determined rather swiftly. The effect of the reaction is to be considered either positive or negative, but the intensity of the end feeling often remains the same - powerful.
In the instance of withdrawal from an idea, it must be that the idea in of itself was drudging and hardly stimulating - or perhaps it was so treacherous that the individual sought to immediately escape and repress reaction. Make no doubt, however, that the INFP will inevitably be forced by natural inclination to eventually face this fear at some later point, no matter how long it might take. To deny facing it would be to deny one's own fundamental identity and duty to pursue the Truth.
When choosing to delve further into an idea, Ne continues until it eventually does react, withdraw, or reach a dead end - that is, Fi has adequately judged and the need to collect more data has apparently abated. Here, the magnitude of emotionality is cumulative; Fi will centralize itself around an idea and pigeonhole itself into one end of the spectrum of positivity and negativity, filtering out the opposing connotation and its sentiments for the time being. Ne will run just as rampant in this instance, but its expansiveness is reduced to orbit solely around the pressing Fi matter. Will the INFP choose to indulge in euphoria or melancholy, fear or courage, passion or disillusionment? Hence, we see how Fi functions in dichotomies.
An apt example of the Fi-with-Ne delve would be an archetypal INFP, Hamlet. In his soliloquies, the audience can observe how his rhetoric increases in momentum just as his passion and emotions do. In his "To be, or not to be" speech, we observe Hamlet initiating with merely deep contemplation, which quickly descends into impassioned inquiry:
Then, as his climax of emotions and sweeping finales and Fi conclusions:With a bare bodkin? Who would fardels bear,
To grunt and sweat under a weary life,
But that the dread of something after death,
The undiscovered country from whose bourn
No traveler returns, puzzles the will
And makes us rather bear those ills we have
Than fly to others that we know not of?
Dead end, indeed.Thus conscience does make cowards of us all,
And thus the native hue of resolution
Is sicklied o'er with the pale cast of thought,
And enterprises of great pitch and moment
With this regard their currents turn awry,
And lose the name of action.—Soft you now!
The fair Ophelia! Nymph, in thy orisons
Be all my sins remembered.
Tertiary Introverted Sensing (Si)
The use of the tertiary function is less conscious. In the instance of the INFP, Si gives a predisposition to react and withdraw (as mentioned above) since it compels the individual to recall past events, experiences, and ideas which either harmonized or disharmonized the balance of Fi. The aforementioned "premature judgment" relating to reaction applies here, as does a "previously known fear" often lead to withdrawal, both decisions brought upon in part by Si.
Tertiary Si gives an effect of "selective eccentricity" in the case of INP's. Ne gives the INFP natural inclinations to seek out new ideas and experiences, but the individual will always remember the events and experiences which particularly stood out - for better or for worse. Essentially, the memories and the data Si stores often depends on how much value Fi imparts to them. Should the individual place tremendous value upon some idea (perhaps it resonates as the very essence of him or her), Si might be utilized to be astonishingly meticulous in recall to the effect that one might mistake its level of development to be that of an SJ's. Though the nature of the INFP is random, painstaking action might be undertaken to preserve the memory of some ideal.
The development and inclusion of Si can be reassuring or disheartening to the INFP's ideals depending on the perceived information; do experiences and facts contradict or imbue one's values? Here, we see that the past can have a dramatic effect on the development of an individual INFP.
Inferior Extroverted Thinking (Te)
In daily life, Te is often to be feared, not because it is necessarily seen as trivial, but because it is essentially the very judging process which might undermine the idealistic system Fi operates under. Fi seeks an inner harmony which Te, in its tangible objectivity, is prone to deny or refute in favor of impersonal Truth. This is not to say that the two are doomed to perpetually conflict by any means - it is just perhaps rarer that the two do harmonize because of their different mediums (introverted versus extraverted) and method of rationalization (feeling versus thinking).
However, the INFP certainly has the capacity to wield Te effectively. In the instance that Te is tapped (which may occur under eutress or distress), the INFP transforms into the oft-mentioned crusader of good (or perhaps, the harbinger of evil). This is a point in which the individual is so impassioned and vigilant in maintaining the integrity of Fi that Te must be and is justifiably wielded in upholding such values.
The use of Te does not necessarily have to bear such drama and theatrics, however. The possible stress incurred by using Te simply needs to be overshadowed in lieu of an Fi desire; why not plan out a first date or justify and rationalize one's actions if one's feelings dictate it is feasible and even beneficial to do so?
As Te develops, the INFP either must twist and adjust his or her ideals to compromise or risk a collapsing disillusionment. In some ways, this represents the "ideal idealist" - one who is realistically idealistic.