Introverted Sensing (Si)
Introverted sensing is an irrational, introverted, and dynamic information element. It is also referred to as Si, S, experiential sensing, or white sensing. Si is associated with the ability to internalize sensations and to experience them in full detail. Si focuses on tangible, direct (external) connections (introverted) between processes (dynamic) happening in one time, i.e. the physical, sensual experience of interactions between objects. This leads to an awareness of internal tangible physical states and how various physical fluctuations or substances are directly transferred between objects, such as motion, temperature, or dirtiness. The awareness of these tangible physical processes consequently leads to an awareness of health, or an optimum balance with one's environment. The individual physical reaction to concrete surroundings is main way we perceive and define aesthetics, comfort, convenience, and pleasure.
In contrast to extroverted sensing (Se), is related to following one's own needs instead of focusing on some externally-driven conception of what is necessary to acquire or achieve. So, whereas Se ego types feel capable to evaluate how justified others' preferences are, Si ego types will try to adjust to them in any way possible (given that it does not extremely affect their own comfort), wishing to minimize conflict. In contrast to introverted intuition (Ni), Si is about direct interaction and unity (or discord) with one's surroundings, rather than abstract process and causal links.
Types that value Si prefer to spend their time doing enjoyable activities rather than straining themselves to achieve goals. They like to believe that if activities are done with enjoyment, people will give them more effort and time, and also becoming more skilled at what they are doing in the long run. They believe that goals should suit people's intrinsic needs rather than shaped by the demands and constraints of the external world, and so do not try to force others into doing things they don't want to do. They also try to be easygoing and pleasant, preferring peaceful coexistence to conflict, except when their personal well-being or comfort is directly at stake.
Si as Leading Function
A strong ability to recognize internal physical states in themselves and others, to understand how these states are reached, and to recreate and avoid these physical states. Individuals who possess Si as a base function are drawn to situations that satisfy their inner physical experience. Whenever Si base function individuals are taking part in something that involves recognizing, recreating, or analyzing physical states, they feel a great deal of personal power and enthusiasm.
The avoidance of discomfort is one of the primary motivations of these types. Feelings of internal discomfort can arise from a tense psychological atmosphere, working too hard and sapping the body's resources, being pressured by other people or by numerous "things to do," and from unsatiated or oversatiated physical needs. These types tend to quickly recognize and be quite vocal about discomfort that arises and either take clever measures to dissipate it or simply get out of whatever is bothering them. They are very receptive to other people sharing feelings of discomfort with them and can help alleviate the tension and offer good solutions.
Si leading types are constantly adjusting themselves to their environment (which includes the people around them), and rarely have any fixed ideas about what is "appropriate" to desire in a given situation. Thus they are willing to accommodate other people's needs in an ad hoc manner. It is enough for something to "feel right" for them to justify doing it. This behavior may seem random to outside observers, since it is concomitant with weak Ni.
Si as Creative Function
The individual is naturally good at organizing relaxing activities and recreation and making sure people are calm and enjoying themselves, but displays this behavior and skill when he sees a specific need for it rather than doing it automatically, all the time. The individual does not place emphasis on being calm and balanced all the time, as opposed to those with Si as a leading function.
The individual is attuned to people's tastes and personal preferences and likes to do things for or give things to friends and family members that will cause them to enjoy themselves and gain pleasure. For example, creating a comfortable, clean, and spacious setting in the home, taking them out to do something they enjoy, or finding opportunities and people with whom they can pursue their hobbies.
Si as Role Function
The individual dislikes it when others emphasize the need for relaxation, enjoyment, and activities that are supposed to bring these about, because what they need internally is just the opposite â€” a need for action and resolve. Rather than spend their time trying to "listen to what their body is telling them," they need to have clear external demands that are able to overcome their sense of uncertainty and hesitation.
Si as Vulnerable Function
Individuals who possess introverted sensing as a 4th function tend to be negligent to the effects of Si and have the view that Si aspects are of less importance than others for achieving their goals. They put a low priority on the physical, short-distance, here-and-now in relation to longer-distance and longer-term considerations. A typical manifestation is a lack of concern for small aesthetic details, since a greater focus is given on the opinion that, in the longer term, taking care of them is a never-ending exercise. This is also manifested in a relative lack of awareness of the immediate surroundings, as in noticing where objects may be if you don't have to deal with them particularly, and of your own physical sensations.
A lack of concern for small aesthetic details is more visible in the LIE; in the case of the EIE, the low focus on Si is more noticeable as a dislike for low-level practical details, such as filling up forms, signing documents, or filling tax returns. Due to individuals who possess introverted sensing as a 4th function believing that Si aspects are of less importance, they tend to be thrown off course by unthought of, new or neglected Si matters.
Si as Suggestive Function
The individual tends to be chronically unaware of his own bodily processes, including physiological sensations and a sense of balance and alignment with one's true desires. He sometimes has peculiar preferences or tastes, which he himself is unable to understand or fulfill. The individual almost never emphasizes his attractiveness or sexuality overtly and publicly, but dreams of being pleasing to the senses to at least a small circle of trusted friends and partners who are able to develop and enhance his sexuality and attractiveness in a trusting atmosphere.
Si as Mobilizing Function
The individual has difficulty producing pleasurable sensory experiences for others and for himself, but likes to talk about pleasure, enjoyment, and relaxation, hoping that someone nearby will take the hint and take the lead. The individual tends to periodically get wound up and uptight and is generally unable to resolve these sensations himself. He needs someone to help him relax and take an internal look at whether he actually needs or enjoys what he is doing, and what might be the source of the tension that has built up. He can tend to extremes in this area, either depriving or indulging the senses to an unhealthy extent.
Si as Ignoring Function
The individual is perfectly adept at evaluating his physical state and the quality of his sensations, but gives priority to the external act of experiencing and interacting with the world. He gets impatient with those who stubbornly focus on harmony and equilibrium when there are things to be done in the outside world. According to these types, the exploration of the sensations is something that should be done in private on one's own time, but in public people should be ready to interact, get involved, and command situations without having to weigh out everything first.
Si as Demonstrative Function
The individual is confident of his ability to recognize and evaluate the physical condition and well-being of himself and others, aesthetic sensations, and the internal effects of sensory stimulants such as good food and relaxing situations. He can provide a convincing evaluation of these when prompted, however, he regards soothing, relaxing things and discussions of them as sources of amusement rather than a priority in life. He does not treat them very seriously or allow himself to engage in them very often, despite his overall confidence in these areas. When he does choose to focus attention on his physical condition and well-being, he is more likely to prefer a Se approach and impose a strict, demanding dietary or exercise regimen upon himself or others.