Conventional measures of mental ability, such as intelligence tests and scholarship, show some of the very highest records belong to INFP and INFJ types, who relegate thinking to last place or next to last. The preference for thinking appears to have far less intellectual effect than the preference for intuition, even in some technical fields, such as scientific research, where its influence was expected to be most important.

In teaching, the other main problem related to type is the students’ interest. Intuitives and sensing types differ greatly in what they find interesting in any subject even if they like, that is, are interested in, the same subjects. Intuitives like the principle, the theory, the why. Sensing types like the practical application, the what and the how.

They [INTJs] are likely, however, to organize themselves out of a job. They cannot continually reorganize the same thing, and a finished product has no more interest. Thus, they need successive new assignments, with bigger and better problems, to stretch their powers.

We cannot safely assume that other people's minds work on the same principles as our own. All too often, others with whom we come in contact do not reason as we reason, or do not value the things we value, or are not interested in what interests us.

The visions of the INFJs tend to concern human welfare, and their contributions are likely to be made independent of a mass movement.

By developing individual strengths, guarding against weaknesses, and appreciating the strengths of other types, life will be more amusing, more interesting, and more of a daily adventure than it could possibly be if everyone were alike.

... much seemingly chance variation in human behavior is not due to chance; it is in fact the logical result of a few basic, observable differences in mental functioning.