"INTJs are strong individualists who seek new angles or novel ways of looking at things. They enjoy coming to new understandings. They tend to be insightful and mentally quick; however, this mental quickness may not always be outwardly apparent to others since they keep a great deal to themselves. They are very determined people who trust their vision of the possibilities, regardless of what others think. They may even be considered the most independent of all of the sixteen personality types. INTJs are at their best in quietly and firmly developing their ideas, theories, and principles."
—Sandra Krebs Hirsch