In all human thought there is basically an inherent dichotomy present between two categorical trends on a very structure phenomenon. You either love a characteristic, or you hate a characteristic. You either organize or divide(chaos). You either live or you die. The odd thing about this phenomenon is that the individual projects both at the same time(unconsciously). A person has to see non-love to love someone. A person has to see organized structures to divide them. In the end you have a sort of duality in the human mind that the conscious isn't aware of completely.
This could translate to functional criteria in individuals in the realm of Socionics. When we look at model A, there are 2 sets of 4 functions. Each set represents a trend in the individuals characteristics. The beginning of the model begins with the two dominant conscious functions(functions 1 and 2) of the individual. These functions are mainly conscious(though they can drift into unconscious territory). Every conscious function is paired with an anti-thesis unconscious function(functions 7 and 8). Ex: If a person's main functional basis is to divide and analyze, then unconsciously they have structured reality into categories that require dividing. The antithetical functions are the bottom two functions of Model A. The second row of functions(functions 3 and 4) are the motivational functions of the chart. They are basically the motivating influence behind the dominant two functions in the chart. Basically without awareness, the person is accomplishing the purpose behind these functions. If a person is dividing structured categories into chaos(analysis) then the person is true to reach a point of unconditional love or neutrality to all attachments. The third row of functions are the conscious antithetical influences of the individual. They are extremely dominant in the person's conscious mind, but they are protested and even despised. If a person is trying to divide and create chaos, then the person has a conscious connection to and completely despises conditional attachments and non-neutrality. All the functions flow together in Model A as they are extremely connected in how they work and influence the individual.
The Extroverted/Introverted dichotomy within Model A is a bit paradoxical though. All individuals do have Extroverted domination and Introverted domination at the same time. To see this though, one must ask what exactly is “Extroverted” and “Introverted” behavior. The question is completely paradoxical. The reason being that all behavior is extroverted. Whether the individual is completely talkative and aggressive in social conversation or completely quiet and to oneself, the person is still exhibiting traits specific to the extroverted dichotomy due to both actions being observable and overt behaviors. The question is, what exactly does this mean? Take the original scenario from the previous paragraph: If a person is analytical minded and striving for chaos in that it is looking for the pure essence something, how does this translate to overt behavior. There is sort of an antithetical basis between the introverted and the extroverted territories of an individual. If a person is analytical in mind, this will translate to perfectionism overtly. The individual mind that is trying to reach the pure source of an idea usually tries to perfect things on the outside. This could lead to some possible obsessive compulsive behaviors. The individual would be trying extremely hard to purify things on the outside world, having no detailed systematics to base their overt behaviors on. This can lead to “flip-flop” obsessions, where the individual is completely unsure of their overt systematics. For example, take a chemist. The perfect amount of some compound has to be added to properly complete an experiment. Since the individual is trying to break away from systematical isolations, this can be a very difficult task. The individual may keep adding the compound to the experiment, up until the point where most people would stop. This is an individual though has a hard time stopping. He keeps adding extremely small amounts, trying to get the perfect amount of solution. Yet he can not stop himself, because he doesn't have a systematic register to stop. He doesn't know the social parameters in which he should stop. He continues onward attempting to get the magical perfect number that is almost impossible to get. Reversely, if an individual is attempting to structure reality based upon a detailed observation, one that is more stereotypical in regard(common sense smarts), the individual is going to be more confident and rigid in their overt behaviors, attempting to adapt things perfect to their set systematics. The obsessive tendencies would be more internal than external, as the individual is looking for the correct detailed approach based on what they think to be their proven observable components. The individual believes he has the correct and proper way to do it, and he will not stop until it is just the way he envisions it. If the systematic empirical observations are not to the point of where he envisions them before hand, he will continue to push. This individual knows where he wants to stop though. He knows exactly what he wants, and he uses his common sense to achieve it. This is how -Ti/+Te compares to +Ti/-Te.
These functional divisions both compare directly to their opposite dual “feeling” functions. -Ti/+Te to +Fi/-Fe and +Ti/-Te to -Fi/+Fe. These work mutually on a very similar functional level. The +Fi/-Fe attempts to reach some ground of purity(similar to -Ti/+Te), except it relates to objectifications. If -Ti/+Ti is trying to remove systematics, then +Fi/-Fe is trying to remove critical objectifications. It wants to accept all things as equal. It also works antithetically with -Fi/+Fe as the individual who is dominant in this function sees the latter naturally and is attempting to remove it. The +Fe component of the function can come off as somewhat harsh and unwavering to everything. This is because the +Fi portion is attempting to create neutrality towards all attachments. It out of all is trying to treat everyone the same. This can make the individual blunt and always wanting things fair and unbiased. This can sometimes make the individual better in group situations rather than one on one where (especially the logical types) they may come off having a lack for the social norms. Oppositely, -Fi/+Fe is trying to create a divide. It wants to find the perfect person to get along with. This can make the individual critical of everyones faults in comparison to their systematic model created by +Ti/-Te. It wants to separate and divide and find its true companion.
S/I functions to follow