Recently I come up with an understanding of the dyads of IEs when I am debating with some MBTIers in a Chinese community. Based on the debates and several old articles and posts, I formed the understanding and then I found out that it seems to be clear to interprate the dyads through the elemental dichotomies. Feel free to challange my perspectives.
Key: abstract/involved. Abstract information often means essential aspects. For one thing, the abstract essense is unique while the involvement has many possibilities.
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Irrational dyads
Si: Field, Dynamic, External, Involved
Ne: Object, Static, Internal, Abstract
Ni: Field, Dynamic, Internal, Abstract
Se: Object, Static, External, Involved
At first, each dyad (eg. Si-Ne) offers all aspects of irrational information.
Then the difference lies in the abstract side. For the Si-Ne dyad, the essense lies in static objects. So there's only one essense for each object but a number of different processes(dynamic) to link (field) the objects are possible. -> Judicious
For the Ni-Se dyad, the essense lies in dynamic fields. So while there are many different static objects, there's only one essential process to link them. So no matter how many objects are there, there's no need to be judicious. -> Decisive
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Rational dyads
Ti: Field, Static, External, Abstract
Fe: Object, Dynamic, Internal, Involved
Fi: Field, Static, Internal, Involved
Te: Object, Dynamic, External, Abstract
At first, the dichotomies show why Ti-Fe is a dyad while Fi-Te is another. Also, from the perspective of dichotomies, rational elements are rational because they give internal information involved meanings, and they sees abstract essenses from external information. This reveals a process of judgements.
Then the difference again lies in what is regarded as the essence. For the Ti-Fe dyad, the only, unique essense lies in static fields. Thus, there could be many different perspectives while the essential thing is the consistency of the relationships. The involvement lies in dynamic processes thus emotions and atmospheres are preferred. ->Merry, Subjectivist
For the Fi-Te dyad, the unique essense lies in object dynamics. As a result, while a lot of methods exist, there is a unique one - the optimal one, the "most correct" one. On the other hand, the involvement lies in static fields thus personal relationships and moral judgements are preferred. -> Serious, Objectivist