Sorry about my confusing summary, it makes sense in my mind..

Accepting a presented truth as absolute truth, not a natural skeptic, but then feeling that truth can't be known and throwing it all away

Here's the original

Phase I (Childhood)

This phase is characterized by the emergence and differentiation of INTPs’ dominant function, Introverted Thinking (Ti). Early in life, INTPs often employ their Ti to focus on one or two pursuits. They may, for instance, use it to master video games, program computers, get good grades, or perfect their 5 K time. Since Ti is a Judging function, INTPs tend to take themselves and their lives quite seriously. Even from a relatively young age, they are self-disciplined and goal-oriented, striving for excellence in whatever captures their interests.

While often described as pure skeptics, this is not characteristic of many Phase I INTPs. While INTPs are naturally logical thinkers, they, like ISTPs, are not born skeptics. INTPs start with a given (T), and if clearly not unreasonable, will assume it true unless their Ne or Si suggest otherwise (functions which in this phase are not well developed). INTJs, by contrast, whose first function is Intuition (Ni), do not start with a given, but approach things more openly, through the eyes of perception. They use their Intuition to discern whether or not something seems viable. Consequently, INTJs are often ahead of INTPs, as well as most other types, when it comes to formulating their own personalized worldview.

Phase II (Adolescence-30s)

Once their dominant Ti reaches a certain level of consciousness and differentiation, INTPs’ inferior function, Extraverted Feeling (Fe), enters the picture and begins to play a more influential role. INTPs are not immune from the dominant-inferior wrestlings described in our Introduction, making this phase as challenging for them as it is for other types.

Phase II INTPs also show increasing use and development of their auxiliary function, Extraverted Intuition (this can also begin in Phase I for some INTPs). During this phase, INTPs often develop a stronger interest in intellectual and philosophical endeavors, poised to see and understand “the big picture.” They also become more skeptical toward certain Ti conclusions they made in Phase I. Developing their Ne involves an opening of prior judgments to allow an influx of new information. But since Ne is extraverted and expansive, INTPs must explore a breadth of ideas before they feel confident about who they are and what they believe. Thus, Phase II INTPs may find it much easier to identify what they don’t believe than what they do believe. Many will struggle with nihilism and relativism, worried that they may never find absolute truth. It can therefore take INTPs a great deal of time, even well into their thirties, to discern what they believe about the world and about themselves, let alone figure out what they should be doing. Unfortunately, societal pressures and expectations often push Phase II INTPs (as well as other types) into relationships or careers well before they are ready.

Phase II INTPs may also begin to tap into their tertiary function, Introverted Sensing (Si). They use their Si to recall past experiences and acquired wisdom. This prevents them from having to retread paths they have already explored in the past