TeSi Book Excerpt

The TeSi type emerges when the Te-Fi oscillation is primary and lead by Te, while supported by the Si-Ne perception oscillation. Having Te as a lead process, the TeSi type will have a noticeable presence, often speaking their mind directly alongside snappy gesticulations, a rigid posture and a matter-of-fact voice.However, by far the most pronounced visual quality of this type will be their mouth, which will be peculiar in the diverse expressions it makes and the extent to which these expressions are generated. As an Fi type, the TeSi will be subject to accidental and asymmetrical muscle contractions as they speak but, being a type which articulates often, these asymmetries will be commonplace.

Their mouth will fall into peculiar shapes, tensing near the nose and sometimes creating a horizontal splitting of the cheeks. In many TeSi the continual vertical stretching of Fi causes their facial muscles to create a taut square effect in the area around their mouth, as seen in Figure 48.d.

The depressor angili oris muscles, which pull the corners of the mouth downward toward the chin, are directly opposed to the levator labii superioris  muscles which pull the corners of the mouth upward toward the nose. When both are engaged, this creates the four points of the taut square. This effect can appear in others with Te-Fi as a primary oscillation, but is perhaps most noticeable in this type.

The TeSi, like the SiTe, has a bit of a droop to their eyes. Having Si leading over Ne, their brow will often become upward turned at the center of the eyes and slant downward at the outer edges of the eyes. Occasionally, their eyes may become naïve and childlike as they toggle lightly across the environment, but will usually remain unchanged and focused forward with a dullness about them. As a judgment type, their body will not be steered by the direction of their eyes, but instead their head and body will move as a cohesive entity, independent of what the eyes may be glancing at.

The TeSi will be an expressive type, yet their expressions will be cold, suggesting a sort of mechanical indifference on the surface, while thinly veiling many private feelings and vulnerabilities. Emotional energies, such as sorrow or anger, may be present in them but these feelings will seep out of their voice sporadically instead of through a deliberate coating of pathos over certain words. Indeed, their emotions may be far more discernible through this rawness than through a coordinated effort.

Special training or a position as a spokesperson may lead to the development of some elongation of sounds for emphasis, but always their voice will lack the sensitivity of an ethical process such as Fe. An element of rigid calculation and sharpness will triumph over their speech. We will often hear a nasalization of the voice; a pinched tonality that runs opposite to the breathy tones of Fi. This tonality will be accompanied by many snippy gestures such as head shaking, head nodding and shoulder shrugging.

Often their trademark nonchalance will be accompanied by a snappy sense of humor; one that aims to take material consequences to their natural conclusions in the most sarcastic or self-depreciating way. Having Ne, this sense of humor can become very unconventional or quirky and perhaps even enjoy the reactions of being seen as bizarre.


The TeSi is a curious creature, containing gifts both for vast innovation but also practical application. The energies and possibilities seen by Ne-Si are channeled through the practical filter of Te, simultaneously supplying and endless stream of potential arrangements and weeding them down to only those that jive with the way of reality.

Because of this, one of the major subtypes for TeSi is The Entrepreneur. While the NeFi type is more suited to the initial generation of a concept or invention, the TeSi is capable of developing the idea to further lengths by being able to listen and resonate with the optimism of another Ne type’s abstractions (particularly when other practicalists would not) and by applying Te toward their manifestation.

We see a classic example of a TeSi entrepreneur in James Cameron, who has not only created a vast array of imaginary worlds through film-making, but has invented many of the needed technologies for those films himself. He is also one of the only human beings to have manned a scuba tank to the bottom of the New Britain Trench, and is also an avid fantasy writer on the side. TeSi are individuals who not only have multicolored interests, but who often pursue many of them to mastery or high proficiency.

Their logistical methodology and naturally proactive energy will generate and endless assignment of personal projects or goals. In many TeSi, this talent for productivity, once recognized, will be firmly associated to their ego identity. Objective and functional achievement then become synonymous with personal success; creating a self-made standard that demands of the TeSi an unreal level of output.

This mindset will transform many a TeSi into an overachiever or busybody, and if the TeSi is not careful, they may place an unjust amount of stress on themselves, which will be amplified even further if a disconnect exists between their Te and their Fi’s bodily sensibilities.

Another expression of the prolific TeSi can be seen in the the exhaustive writings of TeSi J.R.R. Tolkien, who created an entire fictional world history of more than 3,000 years with internal consistency, while also being a polyglot fluent in more than 15 languages and a full-time teacher at the Oxford University. Yet, despite this immense imaginative capacity, a TeSi will far more often view themselves as a realist and dislike attempts by others to take imagination as anything more than a recreational act.

The energies of Ne are seen as an asset to their overall psychology, rather than the primary motivator of it. We learn from Tolkien[1] that he considered himself primarily a scientific philologist.  His love of writing was more academic and the works he considered most important were his professional publications while his fantastical creations were to him simply a personal hobby.

The societies of enthusiasts which came to surround his fictional work greatly surprised and sometimes alarmed him. Unlike the FiNe, Tolkien’s personality was far from dream-like, focused far more on his career and interest in world history and languages. Yet he presents to us a curious case of a TeSi with a healthy sensitivity to his own polar Fi’s influence.


As a Te lead type, the TeSi can also suffer, particularly in their youth, from a difficulty understanding the causalities of their own emotions and those of others. But unlike other types such as the TiNe or SiTe, whose difficulties commonly lead to an introverted and invisible demeanor, the TeSi’s proactive energy will place them front and center; in the spotlight of criticism – causing them to be seen as eccentric nerds.

These types may be the ones who not only engage in geeky activities, but who, whether accidentally or intentionally, publicize them to their peers such as by indiscriminately vocalizing databits as a situation causes them to be recalled. They may do this with little consideration of the social atmosphere or level of receptiveness of the audience. They may have a talkative bent and not understand when other parties are becoming exhausted with their heavy Te or overwhelming information.

These initially awkward types often develop into successful adults after the pressures of grade school have lifted, and they enter into an adult world which gives higher priority and value to their innate traits. At this point they may also develop more capacity for socialization, however, their relationship with co-workers may still manifest challenges.

TeSi may be challenging to work with, as their awareness of their own logistical efficiencies, combined with an unawareness of other people’s sensitivities, may lead to an inability to grasp the views of others and compromise when collaborating. We see a very convincing portrayal of this subtype in actor Jeff Daniels’ role as Will McAvoy in HBO’s The Newsroom (2012). Throughout this television series we see a realistic drama of the difficulties faced by a TeSi, both emotionally and in the workforce. Often the reactions a TeSi will have to their own emotional difficulties will be very direct – perhaps calloused, blunt and excessive as they combat human fears and vulnerabilities with Te’s methodologies.

The overwhelming power of human emotions will prompt every type to utilize their entire cognitive arsenal toward resolving emotional difficulties in whatever way they can. For the TeSi, this can involve rearranging the logistics of a situation to make it impossible to face the problem or person in question (by resigning, firing, deleting contacts, by moving away), seeing it as the most direct and efficient way to resolve the immediate discomfort.

The refinement of a TeSi’s emotional register often happens largely externally, as they receive feedback from reality as to what the dynamics of emotions are. Not having the sensitivity of Fe’s emotional tracking, they depend more heavily on empirical experience for this, which will inescapably lead to a period of awkwardness until they learn the necessary nuances of human interaction.

In their friction with life, they will manifest the uneducated heart; the raw emotional clashing between one person and another. They embody, like many Fi types do, an excellent window into the reality of the emotional register. TeSi’s, like all Te-Fi types, will have a uniquely created way of managing their own private feelings as well as a very particular Fi emotional palate for things they do and don’t like.


As we noted with Tolkien, history and the accumulation of facts or datasets can become an integral part of this type’s disposition. The TeSi can often be seen as the student in class with unreal, encyclopedic memory or an ability to remember vast amounts of mainstream trivia.  As they go about their life, the TeSi, like the SiTe, will show a keen capacity for archiving isolated tidbits of information for specific use in some future occurrence.

But the Si tapestry of the TeSi is also under constant filtration, as their Te manages the inaccuracies of Si. Because of this, Si will be less nostalgic and more functionally oriented. While SiTe types are more prone to grandfather their Si worldview into their personality, often operating through the same thematic premise that they acquired in earlier decades, the TeSi type will not hold itself so rigidly to these veteran ideas.

We will commonly find this subtype in politicians, news reporters and lawyers – domains that engage many of the TeSi’s chronological and managerial strengths – but equally so in hobbyists and fans of a certain franchise.

Their affinities for taxonomy and history can manifest in a diversity of topics, both professional and recreational. At times this subtype is combined with the eccentric nerd subtype as is the case with TeSi Stephen Colbert; a political satirist, writer and television host.


If the TeSi grows a special interest for the ethical dimension, then their unique Fi palate will manifest itself directly through their Te’s locomotion. While Fe lead types are more predisposed to take a mentoring role in moralistic work, Te types such as the TeSi will utilize their natural ability to organize reality in order to provide practical solutions to social problems which collide with their ethics.

Rather than hosting counseling workshops, they may create a charity organization for a certain unfortunate demographic, or donate a great deal of their income toward that cause. TeSi, having polar Fi, may be heavy philanthropists and advocates of minority groups. They may become a political spokesperson of a cause and use their naturally hard energy and articulation to be the stoic representative for these demographics. We see a strong example of this subtype in Rebecca Watson, a famous American blogger, podcast host and avid feminist.

But the ethical convictions of Fi can take vastly different shapes, not all of which are focused on an altruistic motive. At times the ethics of Fi may become subordinate to Te and merge in such a way that a point of alignment is found between both polarities while still retaining Te as the prime directive.

We find a fascinating example of one such philosophy in TeSi Ayn Rand. Through her books Atlas Shrugged (1957) and The Fountainhead (1943), Rand proposes an ethical code formed through an objective rationality and which operates wholly independent of the social/emotional economy (Fe). Altruism is counted as an abhorrent philosophy which praises the destruction and sacrifice of the self. In Rand’s objectivism, the principle of reciprocity is entirely rejected, and each human is liberated from the ethical burden of others, becoming a single entity responsible for their own happiness and for achieving their own success in all professional and private areas of life.

Yet this does not deny the possibility of giving to others freely out of one’s own love, however it will never be from the intention of forming an implicit emotional contract with others. Here we see an absolute application of Fi’s individualism via Te’s practical approach towards life. It demonstrates a convergence of Te-Fi psychology and a unique reconciliation of Ji and Je where principle is always applied in practice.

Notice, however, that the convictions of Ayn Rand and others like Rebecca Watson equally stem from the personal resolve of Fi, championing for the self-direction and freedom of individuals, absent of any collectively dependent solution. Despite extremely different opinions across many TeSi, we witness that the Te-Fi oscillation will always adhere to this same method of execution.

For a complete account of this type’s vultology, we can look at interviews of the following TeSi public figures:


Name                                      Development

James Cameron                       Entrepreneur

Stephen Colbert                      Eccentric Nerd

John Carmack                         Eccentric Nerd

J.R.R. Tolkien                         Entrepreneur/Historian

Fran Lebowitz                         Logistical Ethicist

Miley Cyrus                            Individualist

Adele Adkins                          Individualist

Savannah Guthrie                   Executive

Germaine Greer                       Individualist/Historian

Ayn Rand                               Logistical Ethicist

This snippet has been imported from Cognitive Type, with the author’s permission. We hope you enjoy!


© Copyright 2012-2020 J.E. Sandoval


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