I took some acid last weekend and was thinking a lot about how thinking works.
It seems obvious that everyone has tens of thousand implicit beliefs about things, and that those beliefs relate to each other in some sort of structure. The way I see it -- learning is a process of relating small units of belief to each other and creating larger units. Since our consciousness can only really deal with around 7 propositions (or units) at a time, larger units are more efficient in that they carry more information but also more risky because the internal mechanics are taken for granted.
We can think of someone's overall system of beliefs as a "ground level", where a bunch of unrelated primitive beliefs sit, a "first level", where primitive beliefs are grouped together into very basic theories, and then hundreds of other levels that grow to staggering heights of abstraction. Scaffolding on top of scaffolding on top of scaffolding, etc. Consciousness is basically a continuous conference call between 7 people at a time sitting on different places in the scaffolding.
Back to MBTI, the role of perceiving functions is to add new people to the conversation. Sensing will constantly add in guys sitting on the sensory input scaffolding. (Just like all beliefs, sensory beliefs build up from little units like everything else -- from primitives at the bottom like "this spot on my retina is currently being hit with light" to "i see a cat".) Intuition is constantly building bridges between places in the scaffolding and adding the guys standing on those bridges to the conversation.
The conversation itself is mediated by Thinking and Feeling, which gauge what each member brings to the conversation. If the member isn't relevant, they'll just be replaced with a new member from the Intuition/Sensation queue. If the member is judged more harshly, Thinking/Feeling will tear down the levels of scaffolding that created that person in the first place. Likewise, if they're judged favorably, Thinking/Feeling will give give them a louder voice for the next conversation they're a part of.
Over time, the scaffolding gets higher and higher and more and more interconnected due to the work of Intuition/Sensing. It also gets more and more specialized because Thinking/Feeling have torn down areas of the structure that haven't been good in the conversation in the past.
Anyway, in this narrative, the role my Ti plays in my thinking is that it's just sitting there monitoring what I'm thinking about (the conversation) and either saying "that guy isn't contributing" or "you guys need to listen to this guy". Since I'm an Ni dom and I'm more focused on creating bridges between spots in the scaffolding and throwing those guys into the conversation, my Ti spends much of its time knocking these bridges down.
Sorry if that made no sense.