According to Briggs-Myers, “Thinking is essentially impersonal. Its goal is objective truth, independent of the personality and wishes of the thinker or anyone else.” In contrast, “People (even thinkers) do not like to be viewed impersonally and relegated to the status of ‘objects.’ Human motives are notably personal. Therefore, in the sympathetic handling of people where personal values are important, feeling is the more effective instrument.”

She says that Thinking types “value logic above sentiment.” They “are usually impersonal, being more interested in things than in human relationships.” They are “naturally brief and businesslike, they often seem to lack friendliness and sociability without knowing or intending it.” Finally, they “suppress, undervalue, and ignore feeling that is incompatible with the thinking judgments.”

In contrast, Feeling types “value sentiment above logic.” They “are usually personal, being more interested in people than in things.” They are “naturally friendly, whether sociable or not, they find it difficult to be brief and businesslike.” Finally, they “suppress, undervalue, and ignore thinking that is offensive to the feeling judgments.”

One can see from these quotes that the MBTI split between Thinking and Feeling corresponds precisely to our division between objective and subjective. From a researcher’s viewpoint, this means that we have ‘hit the jackpot.’ We don’t have to study the relationship between objective and subjective all by ourselves. Instead, we can use the information that has already been gathered by MBTI in its study of Thinking versus Feeling.

But, MBTI talks about three other major splits. Are these as fundamental as the separation between Thinking and Feeling? Let me answer this question by describing my encounter with MBTI. While I was working on the rough draft of this book, my brother was putting together a website describing the theory of mental symmetry. When he posted his information, he offered a prize to anyone who could find a critical flaw in the theory. The major challenge came from a researcher in MBTI, who claimed that it was more complete than our system. In response, we took several months to analyze MBTI.

The correspondence of objective and subjective with Thinking and Feeling was the easiest to notice. As you can see from the material written so far, this division formed a basic part of my analysis. As a person, I had spent years struggling with this separation. As we went further and studied the three other divisions, we saw that they were also fundamental. And when I examined my research and writing in the light of MBTI, I noticed that I too had discovered these same basic splits. Therefore, I decided to revise this book in the light of our new understanding.

So, which is the better theory? MBTI or mental symmetry? Well, how does one evaluate a theory? With Teacher emotion. And what produces positive Teacher feelings? Order within complexity. Therefore, the theory which manages to tie together more information in a tighter way is the winner. And if one theory can subsume the other—if it is a superset of the other—then its victory is absolute. This I propose to do in this book. Among other things, I will be explaining all of the fundamental aspects of MBTI in terms of mental symmetry. Will this mean that MBTI is wrong? No, that is a Perceiver question rooted in Mercy divisions. Rather, it will mean that MBTI is a Teacher subset of mental symmetry. Not wrong, but incomplete. What makes a theory incomplete? Usually, faulty assumptions. But what are the faulty assumptions of MBTI? Ah, first we have to describe the theory. Then we will look at its assumptions. So, let us move on to the next MBTI division of Sensing versus iNtuition.