Are there not 8 functions by definition?
Socionics identifies the dichotomies S/N T/F, each of these 4 requires a category of cognitive thought to explain how they are different, we call these functions. There is also a 3rd dichotomy, E/I which splits each of these categories into 2, meaning that we now require 8 functions to include the E/I preference. But thats it, there are no more dichotomies that socionics identifies, therefore by definition all cognition must come under 1 of these categories. As all people use all types of cognitive thought, we have the idea described by model A, that all people use all the functions, they just do so with greater or weaker strengths etc, producing 16 types (j/p although not a dichotomy, in model A has the effect of changing the order of functions therefore doubling the number of types to 16) .
Now, socionics with subtypes essentially describe 32 individual types, they are just not as well understood as the 16 types we usually use. Is this because there is infact a 4th dichotomy that has not been identified very well and we only see the end product in people, hence why they are relitively poorly written and often people find it hard to identify with a subtype? quite possibly.
If you think about for example S/N, if you believe this is a
discrete preference, same for T/F and E/I, then you will get 16
discrete types. If you believe that S/N etc are
continuous preferences, then the 16 types will become points on a
continuous line. If this is indeed the case, we could continue to find ways to divide people with finer and finer
continuous dichotomies to get 32, 64, 128 ..... types, as all we would be doing is finding more accurately where someone belongs on this continuous line of type.
I hope this makes some sense
