as a base (1st) function (LII and LSI)
The individual views reality through the lens of logic, immediately recognizing the correctness and appropriateness of things and their proper place in reality and in his system of views and behavior. He freely makes logical assertions, often exaggerated, about new information and experience. He holds highest those rules to which exceptions do not exist, and is a habitual critic of people or things that don't follow a set of rules, whether they are those accepted by the community, or his own, or even the other person's. Although he is able to adopt others' rules, his own are always the last word, and these are subject to continual refinement.
Often seen as "demanding", due to high standards.
as a creative (2nd) function (ILE and SLE)
The individual easily generates logical systems and formulations to explain a set of phenomena that he has experienced or studied. However, these logical systems or explanations are not viewed as permanent or all-encompassing, but can be improved upon or even discarded as new experience and information is added.
as a role (3rd) function (ESI and EII)
The individual is able to talk about things from a dispassionate academic or theoretical point of view for brief periods of time, but seems overly bookish when doing so and tends to grows tense. When feeling obliged to justify logically a personal decision taken for reasons determined by , the individual attempts to do so but grows quickly annoyed especially if the inconsistency in the logical argument is pointed out. He then either explains the ethical motivation or avoids the issue altogether.
as a vulnerable (4th) function (SEE and IEE)
The individual has a tendency to either completely reject or completely embrace a source of theoretical knowledge, but does not like to reveal the source or his adherence to it.
He prefers to limit the number of theoretical categories he works with and tends to see new terminology, systems, and rules as being arbitrary and unnecessary until he at last discovers their necessity for himself through extensive personal experience.
He may be able to express his views clearly when given the time, but he is not prepared to deal with people who challenge his views and draw him into logical arguments and disputes. For this reason, he is reluctant to publicize new determinations and opinions until he is absolutely sure that they are right and that he can support them thoroughly to anyone who challenges them.
as a suggestive (5th) function (ESE and EIE)
The individual has great admiration for people with well-developed systems of views. He especially likes clear and concise explanations of concepts, rather than a lot of background information about them that is not directly pertinent. He wants his actions to make sense, and thus needs external assurance that the conceptual understanding behind them is correct. If he cannot find a source of certainty, he may become flustered and unable to act rationally at all.
as a mobilizing (6th) function (SEI and IEI)
The individual seeks clarity in his system of beliefs and understanding and enjoys entertaining new concepts and being included in philosophical discussions where new concepts and systems of thought are introduced. He is uncertain of the logical clarity backing his actions, and thus seeks external assistance in attaining a degree of reasonable competence in this realm. Structure is sought as more of a means to an end, a background guide to facilitate the growth of the individual's main goal.
as an ignoring (7th) function (LIE and LSE)
The individual understands easily, but is largely indifferent to, discussions that focus on the internal logic of ideas and systems. The individual perceives such logical systems as largely worthless to his goals and finds them completely uninteresting and unproductive.
as a demonstrative (8th) function (ILI and SLI)
The individual often criticizes others' views from a logical standpoint, picking apart statements and postulates and showing that they are logically flawed. However, he does not choose to do this excessively and does not expect that reality can be accurately expressed in a neat logical systematic anyway.