Introverted feeling types have a wealth of warmth and enthusiasm, but they may not show it until they know someone well. They wear their warm side inside, like a fur-lined coat.

Although intelligence tests are usually speed tests for the sake of convenience, it is debatable whether speed has any rightful place in the basic concept of intelligence.

the present Western civilization ... is dominated by the extravert viewpoint. There are plenty of reasons for this domination: extraverts are more vocal than introverts; they are more numerous, apparently in the ratio of three to one; and they are accessible and understandable, whereas the introverts are not readily understandable, even to each other, and are likely to be thoroughly incomprehensible to the extraverts.

Extraverts ... cannot understand life until they have lived it. Introverts ... cannot live life until they understand it.

... 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.

[On Jung's theory of psychological types:] My mother, Katharine C. Briggs, introduced it into our family and made it a part of our lives. She and I waited a long time for someone to devise an instrument that would reflect not only one's preference for extraversion or introversion but one's preferred kind of perception and judgment as well. In the summer of 1942 we undertook to do it ourselves.

You psychologists focus on what is wrong with people; I want to focus on what is right and what could be right.