Jung does not have a stack, yet I did draw 4 stacks position, one for each function.
The main difference between me and the other sources are these:
1) Every position on my stack exists on Jung typology. As I had implied earlier, Jung originally only have 4 positions: Principal, Auxiliary, Inferior Pair, Inferior function. There is no 5th slot, 6th slot, etc… No trickster slot, etc… None of these.
2) I use the 4 functions because there are actually 4 and not 8.
I think for clarity I would rather explain each “slot” in more detail, more for the sake of understanding rather than officiating anything.
1: Primary function: Primary function is a function that is very or totally differentiated. The attitude is aligned with Extraversion, Introversion or can have an undifferentiated attitude (just N). For example, a person with a strong E direction and long N function won’t use N on an introverted attitude much. However, for most people the primary is very yet not fully differentiated on the attitude, meaning that this function will be mostly used on one of directions, but sometimes will be used in the other direction as well (yeah, Jung typology is more ‘gray’ then black and white – actually, every time I say totally differentiated it is fully black and white, and every time I say undifferentiated is completely gray). If a person has a weak-short primary function, then this function will only be partially differentiated, meaning that it will be more reactive, and this reactiveness for consequence makes the inferior less differentiated as well. So, a person with a short N function will have some few reactive uses of S. When a N-dom person is on an environment that forces the use of the S function, then the N it is imminent that N will have a weak primary function. Also, in the case of a function having an Extravert orientation, it will be more likely short.
2: Secondary function: The secondary function is only partially differentiated, not fully differentiated and that is why the attitude of E/I is not applied to it. The second function depends on the primary function on its use and will have an attitude according to the primary demands, and these demands are not fixed (so a primary i or e function won’t demand anything e/i specific to the secondary function). Just an example, if a Ne type is pursuing a possibility where the person needs to make others happy and ‘conquer’ others sympathy, the person will use Feeling in an Extraverted attitude. If a Ne type is pursuing a possibility that requires an intense feeling, like being on an experience that evoke intense feelings, then Feeling will be on an introverted orientation. Sometimes it will be of neither orientation as well. Along that, since the secondary function is partially undifferentiated, it will also be subject to the convenience of the environment on its orientation, so contexts that requires a more extraverted or introverted orientation will actually affects the secondary function first (and actually the tertiary) and the primary only later. The secondary function is partially reactive, meaning that it will be E or I according to the reaction, however that depends on the intensity of it. This is why we don’t assign any specific attitude orientation (E/I orientation) for the secondary function. A weak secondary function will have a tendency to be quite reactive and adaptive, because it is less differentiated. A normal one will be partially reactive. If the secondary function is long, then it is no longer much reactive. Although I explain this with my words and I like using the word ‘reactive’ from the enneagram (the reactive here is very similar to the reactiveness of an enneagram type 6), it holds completely true to Jung. There is only one exception: If a person has a strong-long secondary function, which implies a long primary function, and a strong orientation towards a E or a I type, then in that case the secondary function follows the primary on the E/I orientation and on the ENFI case we have a Ne-Fe type, on the INFR a Fi-Ni type and that goes on. However, when that happens it is always considered unhealthy.
3: Tertiary: Here we got a little bit on a messy part because I haven’t truly figured the unconscious theory of Jung partially because Jung said that the inferior function is fully conscious in one part and then said the inferior is fully unconscious in another. I avoided reaching the unconscious because not only is hard to understand but I think there are studies that refutes the Jung’s view of the unconscious as primitive and unsophisticated. The tertiary is the inferior pair, and it works as the auxiliary function of the inferior function, but that only has meaning for the unconscious. In conscious terms, the tertiary function should work partially like the second, however it is slightly avoided because the secondary function suppresses it. So, a person will use it the tertiary function also on a reactive way and with the environment influences, and will change the E/I attitude accordingly, this function might aid the primary but will be partially avoided.
4: Inferior: Jung says the inferior is undifferentiated, however I think it is differentiated – it is an avoidance preference, the person avoids it, so that could count as differentiation. It is the opposite of the primary. It will be avoided at all costs, a person only uses the inferior if the other 3 functions can’t be used to solve the issue or solve the issues poorly. In theory, a person that is forced to use the inferior very often gets stressed.
Also, which stacks would be for each type? Well, remember when we speak of a function “stack” for Jung typology, we are only referring to the function-type of Jung typology and NOT the attitude type. With that in mind, the Jung “stacks” are easy:
Type: Primary>Auxiliary>Tertiary>Inferior
Si type: S>T=F>N
Se type: S>T=F>N
Ni type: N>T=F>S
Ne type: N>T=F>S
Te type: T>N=S>F
Ti type: T>N=S>F
Fe type: F>N=S>T
Fi type: F>N=S>T
Fi-n: F>N>S>T
Fe-n: F>N>S>T
Fi-s: F>S>N>T
Fe-s: F>S>N>T
Ti-n: T>N>S>F
Te-n: T>N>S>F
Ti-s: T>S>N>F
Te-s: T>S>N>F
Ni-t: N>T>F>S
Ne-t: N>T>F>S
Ni-f: N>F>T>S
Ne-f: N>F>T>S
Si-t: S>T>F>N
Se-t: S>T>F>N
Si-f: S>F>T>N
Se-f: S>F>T>N
Typology Triad 