Unlike the INTP who seeks to understand principles of the real world, the INFP will be more than happy removing their grasp from the external world. Possibly even be content with finding harmony in the world they have created. So long, as of course they have found harmony of some kind. Such a retreat will advance the INFP further towards the position John Milton was in, where they would be longing for the perfect world that has no place in the external reality. Much like Jung noted about the Introverted Thinking type, that the more he retreats into his inner world, the more he rejects ideas that are oriented around empirical evidence. Therefore his thoughts become mythological because they have little grounding in the external world and because of this they will be unintelligible to others.
A poignant example of this would be an INFP who highly values sensitivity, as most tend to, misunderstanding the situation she/he is dealing with and attempting to be as sensitive as possible in accordance to the situation that they are dealing with. Yet, when they come out to deal with the external world, the other person may perceive them as insensitive, despite their earnest effort and sincerity. That is because the person that they tended to was not dealing with the situation that the INFP has envisaged. This is a consequence of an Introverted Judgment eclipsing the INFP's Extroverted Intuition. Intuition is a perceiving faculty. A function that we collect information with. If this faculty is lacking, we will not be able to solve problems that befall us properly because we will not be aware of what the problems are. We should also note that the Extroverted Intuition of the INFP is often aimed inwards due to the primacy of an Introverted Function-Introverted Feeling. Fi-Introverted Feeling, bends the Extroverted Intuition inwards and therefore creates the effect germane to Introverted Intuition. This leads the INFP, unlike most perceiving types to merely collect information that is fitting with the goals set by Introverted Feeling, instead of collecting all information as their extroverted cousin ENFP would be more likely to...
The INFP may be frozen in only their own perspective. This ossification in their prejudices also precludes them from furthering their quest for a higher purpose, as in that case their Intuition, on which they rely for exploration of ideas becomes unavailable. And moreover, their longing for affirmation of their value systems will preclude them from entertaining new ideas for the purposes of emendation of their current value system. In such cases of neurosis, the INFP will not be able to surrender their current value system, even if it be pernicious because their intense sensitivity will compel them to equate rejection of their values with a denigration of their character. Moreover, they likely will be unreceptive to whatever information contraposes with their Feelings, and therefore exhibit unusual truculence towards all notions that they disagree with. As then, not only must the idea that they embrace derive from the inside, as is the case for the Introverted Thinker, but also it must be in tune with their personal sensibilities. This often leads to INFP becoming very dogmatic in their opinions.
The problem that both of these types incur in regards to diminution of Extroverted Intuition, is that they will tend to make decisions before they have managed to collect sufficient information. And as before mentioned, will not be able to collect information with a truly open-mind as their thoughts are influenced almost solely by the Introverted Feeling to which Extroverted Intuition is a servile lackey. Development of Extroverted Intuition liquidates the dilemma of potential one-sidedness as the auxiliary function becomes emancipated from the serfdom of the superior. Intuition, by property of itself, processes ideas. Thus, in such an event, the INFP will not be afflicted with the malady of collecting only information that is desired by the Introverted Judgment. INPs, as aforementioned tend to explore subjects in great depth with intense focus, whilst the Intuition oriented thinkers (hence, the Dostoevsky example), explore more ideas, yet with less of an intense of a focus. Extroverted Intuition is the most extensive function of all. An INP who has mastered Extroverted Intuition will be able to concoct a worldview that is almost as broad as it is deep. Aristotle and Shakespeare the case in point. Ivory tower academics are examples of INTPs who have not accomplished this task, and Kierkegaard to whose work we can refer to as being stuck in a dimly lit room, is an example of an INFP who has not accomplished the task...
Being a serf of Introverted Feeling, first and foremost, as well as Extroverted Intuition—the Introverted Sensing will pinpoint only the facts that the Introverted Feeling deems important, and those that Extroverted Intuition decides are worthy of speculation. Thus, the INFP with a low self-esteem often easily invokes memories that are unfavorable, and with the high, those that are favorable. As we see that the Introverted Sensing is often entirely at the disposal of the Introverted Feeling.
INFPs are unable to do this because they are unable to separate their feelings from their objective perceptions. Due to this inability, and their unconscious use of the Thinking faculty, they often wish to see the world conform to the way they feel it should be. Intellectually, they hear a dim voice from the background of their psyche pointing out the logical essence of their situation, yet it is often overwhelmed by the despotic tone of their superior Introverted Feeling faculty. The master-slave relationship between the Introverted Feeling and Extroverted Thinking is analogous to that of Introverted Feeling and Extroverted Intuition. The Introverted Feeling only accepts logical explanations that are favorable to itself, and those that are not favorable are either disregarded completely or adjusted to whatever extent necessary to satisfy the agenda of Introverted Feeling. Or in other words, here the INFP will befool him/herself into believing that reality is either something they need not take interest in, or it is exactly the way they want for it to be. Thus, after the INFP has become dogmatic in their opinions, Extroverted Thinking, the most servile lackey of Introverted Feeling will be utilized to pass off what the INFP feels to be the truth as a logically sound argument, which they shall impose on others in a very common-place TJ fashion. Until the INFP has gained conscious control of their inferior function, the self-imposed delirium will not cease. When highly stressed their much neglected impersonal thoughts will haunt them in a form of their unconscious impulses that they neither wish to deal with nor understand. Moreover, it should be noted that INFPs, despite their intellectually adaptable mindset (NP) tend to be rigid in explorations of impersonal ideas because Extroverted Thinking is a J-oriented faculty. For this reason, they may experience difficulties in rapidly subject-changing NTP oriented discussions of ideas, and if their impersonal views are to be changed at all, they must be changed gradually, as characteristically of a typical Judging mindset. For this reason also, INFPs prefer structure when dealing with impersonal matters, as unlike the Introverted Thinkers, they are unable to improvise. Many of the problems above can be rectified through conscious use of Extroverted Thinking. At that point the INFP will be able to recognize impersonal ideas for what they truly are, uninfluenced by their feelings and act in accordance to what is most sound. Not in accordance to what they, or anyone else may feel is desirable. Until then, they will have to rely on the Fi-Te axis(going merely by their feelings that 'feel logical'), the unreliable reasoning that they have. Or the Ne-Te axis, which is to be preferred, as when the INFP extroverts, their Intuitions connect them to logic. Or finally, the storage of concrete information having derived from Introverted Sensing. With that procedure, the INFP will merely memorize how impersonal decisions are to be made. As an NP, the INFP finds this one the least desirable of the three.
The most favorable way is likely the second, that of the Ne-Te axis, as this is the most intuitive approach and requires the least conscious attunement with their inferior function. However, the 'Si method' is likely more conducive to the overall growth of the INFP. Introverted Sensing links the INFP to their Inferior function because it is adjacent to it. Thus an INFP who has mastered Introverted Sensing will be more comfortable with their Extroverted Thinking as the two are intimately intertwined. The INFP shall not make a conscious effort to this, but merely will be successful at this as soon as their Introverted Sensing has developed naturally. At that point, they will also feel their Extroverted Thinking enter the sphere of conscious use. Naturally, the INFP will be most comfortable with 'the feels logical' Fi-Te method. However, the most sound approach to the matter would be the Intuitive. First, cultivating Extroverted Intuition, and afterwards the INFP will feel in closer affinity with Extroverted Thinking than with their primary Introverted Feeling.