FineLine's claim merit another mention.
He argues that a Ti person can be divorced from reality just as much as an Fi person as well as logical thinking is not enough for understanding reality. In other words, it is not enough to think rationally, one must also make accurate observations of reality.
I argued that thinking logically is a prerequisite for making accurate observations in reality. If a person does not think rationally, he cannot accurate organize and understand his observations.
A person who does think logically will be inspired to make accurate observations of the external world because inaccurate observations will in most case appear in his thought in a form of contradictions which he cannot tolerate.
For this reason, it is quite rare that INTPs are divorced from reality.
However, they do appear to be. As Fineline suggests, a Ti person who says it is fair to mistreat a family member seems to be divorced from reality. FineLine seems to argue that the person who behaves in a way that we deem ethically untenable must be divorced from reality. The latter does not follow from the former.
A person may have a clear understanding of reality, for instance he may be a physicist, mathematician or a philosopher yet still mistreat peole simply because he is wicked. Quite simply an understanding of reality and treating others in a way that is ethically justified.
The INTPs who behave in such a way simply do not find treating others in a respectful way to be important. When they say it is 'fair' they are simply looking for a cheap excuse to make their actions seem justifiable in the eyes of others in order to make sure others get off their case.
Again, I see no reason whatever to connect mistreating other people with a lack of objective understanding of reality.
Sorry for returning so late and for skipping so much other good material. But I'll just address this one idea because it was at the core of my objection to your (BlueWing's) viewpoint.
I'm not talking about an inability to observe reality so much as a type of "circumscribed thinking/reacting." Example: The absent-minded INTP professor who runs his life, classes, and family by purely logical principles. He is aware of the emotional side of life, but frankly that side of life seems chaotic to him and so he's too lazy and too afraid of failure to address it. So he simply ignores it and lays waste to the emotions and lives of the people around him. (See the movie "Smart People" for an example.)
Not that Fi is any better. Many INFPs are perfectly aware of things like schedules and boundaries and planning and analysis, but they're too lazy and afraid of failure to apply those things to their own lives. So they ignore those things and lay waste to the plans and lives of the people around them.
In this same context, you frequently arrogate the terms "logic," "rationality," and "reason" to T alone; whereas F only get "emotion" and "fickleness." I'll give "logic" to T and "emotion" to F. But "rational" and "reasonable" aren't merely synonyms for "logical." "Rational" and "reasonable" have broader applications to life.
I see a lot of smart INTPs who engage in wildly irrational behavior by most measures, and who make unreasonable demands of life and the people around them. It's not because they're blind to the realities of life; they just don't want to be bothered dealing with the full complexities of life. Out of laziness and fear they ignore any data that doesn't fit neatly into a simple analytical model they've constructed for dealing with life.
Actually, in practice, it would probably be more accurate to say that the data is usually included but the INTP refuses to act on the data, or acts in a manner contrary to what's expected or in his own interest. Example: a single INTP knows an attractive woman is interested in him, but he's afraid of rejection or failure so he snubs her and drives her away.
Fe tends to spook INTPs. And once the INTP gets comfortable with the concept of simply tuning out uncomfortable facts of life, it gets easier and easier to ignore bigger and bigger chunks of life: Te, Se, Si, etc. INTPs are people, and people are basically lazy at heart.
The INTP's choices and actions are entirely logical within the framework of their own simple analytical model. And I wouldn't characterize that INTP as "wicked" as you've chosen to do; I would prefer to call him lazy and afraid. But in any case, such INTPs are hardly rational and reasonable in the ways they deal with the real world and the people around them. And INFPs do the same thing, albeit using some simplified emotional model (for example, being afraid to take on management roles because they're afraid of Te).
Anyway, that's why I see pure Ti as no more grounded in reality than pure Fi. Both operate as much by exclusion of factors (an attitude of fear or laziness toward toward any environment or actions that don't fit neatly into their model) as inclusion of factors. In a complex world, they're both just running on half of their cylinders. Rational and reasonable analysis and actions in a real-world setting requires being able to incorporate and react to both logic and emotion.
(Oh well, that was kind of rambling. Sorry I don't have time to revise. I'll drop the subject at this point.)
