Well it's actually more of this:

https://oregonstate.edu/instruct/phl...kepticism.html

But a necessary part of science is that every claim it makes is open to doubt. People used to believe that the earth was flat. We believe it is round. Science gives us some good reasons to think so, but it is possible that another theory will come along and show that the earth is a four-dimensional hypersphere instead of a round ball. The case is never closed on any issue, doubt is always possible, and final knowledge is forever out of our grasp. This view will probably upset people who believe in "an absolute truth" and people who believe "there is no absolute truth."
However I wouldn't say that things are "probably" true, because things are either true or it isn't. Reality isn't probable. We have our interpretations of reality, which is going to be 100% wrong, but may still contain a grain of truth and be an approximation of truth.

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As for the mysteries and the confusions surrounding Reinin dichotomies, well the dichotomies don't change the initial classification system of Socionics via observation, it just attempts to justify the classification further by giving it more details. But the details are completely arbitrary.