Si · Introverted Sensation
universal perception
Perceives the subjective impression an object leaves, building an archive of what has worked across prior encounters.
Perceives through inner sense-impressions: abstracting the lasting form of experience and archiving it as precedent. Stability: thoroughly accumulating and archiving verified experience to gain a total and reliable footing in a situation.
MountainShape
Drives
- Store the salient core of each experience as a prototype and precedent for future reference
- Verify before trusting: wary of direct experience until processed and approved
- Preserve what has proven itself: routines, traditions, the personally meaningful
- Attend to what things represent for oneself: personal connection over flashy presentation (Monet's 'what I myself have experienced')
Values
- reliability
- duty done properly
- the little things
- personal history and its meanings
- a well-tended, manageable existence
Fears
- The untested new: a flash in the pan asking to replace the proven
- Being caught unprepared ('just in case' is the standing maxim)
- Waste and recklessness with what took years to build
- Grand speculation that abandons everyday life, viewing the long reading (Ni) as pointless philosophizing.
Gifts
- Commands accumulated detail, and can drown a decision in precedent.
- Detects fakes against the archive, and can distrust genuine novelty.
- Endures long maintenance, and can refuse change until forced.
- Honors ordinary routines, and can maintain a habit long past its usefulness.
Costs
- Sacrifices results to preserve established methods (the Charge of the Light Brigade)
- Dismisses the zeitgeist as personally irrelevant: the Hobbit caught unawares by titanic forces
- Adopts new categories slowly and dismisses radical novelty as untested.
- Keeps comfortable routines long after their original purpose has passed.
Not to be confused with
- Se: Si (the archive) abstracts the species of experience; Se (present contact) lives the instance. Si is wary of the given; Se trusts it. Si conserves energy and attention; Se spends both freely.
- Ni: Si (the archive) is arrested by the impression's every detail and concretizes it; Ni (the long reading) peers behind the impression to the image that caused it. Si reductionist and everyday; Ni holistic and grand. Si perfectionism = meticulousness; Ni perfectionism = idealism.
- Ti: Both meticulous verifiers, but Si (the archive) verifies by cross-examined experience and stability; Ti (strict definition) by deductive consistency of principles.
The five named positions
What this function becomes in the five named positions. The other three pairings appear in the hexagram readings below.
- At the Dominant: Life is anchored in the archive of verified experience: the world's storms are met from a stable moral and practical foundation (Conscience ISFJ, Veteran ISTJ).
- At the Auxiliary: At the auxiliary position (for ESFJ and ESTJ): custody as workmanship. The records, rations, and routines that keep an operation or a household actually fed; what comes in and what goes out, managed with temperance.
- At the Inspiring: At the inspiring position (for INTP and INFP): this function's register is hungered for naively, admired in others, reached for without native skill, and received as a call the ego did not author rather than wielded as a tool.
- At the Nemesis: At the nemesis position (for ENTJ and ENFJ): the pull of precedent the vision-led types refuse, how it has always been done offered against the long read. Contained, it checks the vision against tested practice; fed, the vision shrinks to memory.
- At the Primitive: For Ne-dominants, Si (the archive) is the neglected anchor: bodily signals ignored, routines collapsing, then hypochondriac fixation on details or nostalgic dread under stress; for the Mountain-Mover it is the private scale of meaning dismissed as lotus-eating.
Under pressure
For Ne-dominants, Si (the archive) is the neglected anchor: bodily signals ignored, routines collapsing, then hypochondriac fixation on details or nostalgic dread under stress; for the Mountain-Mover it is the private scale of meaning dismissed as lotus-eating. The archaicized intuition has 'an amazing flair for all the ambiguous, shadowy, sordid, dangerous possibilities lurking in the background': sniffing out every conceivable archaic motive behind others' real intentions; when the unconscious turns antagonistic it produces 'compulsive ideas of the most perverse kind'; allows himself to be abused, then takes revenge 'on the most unsuitable occasions with redoubled obtuseness and stubbornness'. Sacrifices results to preserve established methods (the Charge of the Light Brigade). Dismisses the zeitgeist as personally irrelevant: the Hobbit caught unawares by titanic forces.
The motion (consolidation · Se → Si)
Given experiences A, B, and C, what deeper, truer, more universal experience could they be reduced to?
Across the sixteen
Every type places Si somewhere; the position decides what it becomes. Each pairing is its own hexagram, with its own card and reading. In any position, Si can fail toward too much control or too little; the loop between the two is on the model page.
Sub-dominant · ䷕ 22 · GraceSi · ESFP + ESTPIn hexagram 22, Grace, the archive (Si) sits in the sub-dominant position for ESFP and ESTP, directly under their present-contact (Se) dominant. Practiced routines act as a stable mountain, providing clarifying ornament that gives form to their immediate actions.
Sub-auxiliary · ䷳ 52 · Keeping Still (Mountain)Si · ISFP + ISTP · doubledThe archive (Si) sits in the sub-auxiliary position for ISFP and ISTP. Like hexagram 52, Keeping Still, their accumulated physical experience provides a deliberate constraint, anchoring present actions strictly in what is actually known.
In hexagram 18, Work on What Has Been Spoiled, the archive (Si) sits in the inspiring position for INTP and INFP. They feel called to remedy the decay their branching interests leave behind, requiring patient deliberation to make the repair hold.
Spotting
In the room
- Keeps records, backups, receipts, rituals; maintains things well past fashion
- Compares every new instance to a remembered one before accepting it
- Prepares for contingencies others call improbable
- Loyal to proven brands, places, people, methods
- Notices small deviations from how it was last time
Sounds like
- 'Last time…', 'in my experience…', 'we've always…', 'tried and true'
- Step-by-step recounting with careful, specific detail
- Asks 'has this been tested?', 'what happened before?'
- Understated, temperate register; suspicious of hype
- References tradition, procedure, and personal history as authority
Says
- “Let's check how we handled this last time before we improvise.”
- “It's not exciting, but it has never once failed me.”
- “I wrote it down when it happened: here's exactly what was said.”
- “New isn't better. Better is better, and better takes proof.”
- “Measure twice. We're not doing this twice.”
How to probe for it
- Ask how they decide to trust something new. Si (the archive) wants track record, testing, and comparison to precedent.
- Ask about their routines. Si (the archive) has many, values them, and can say exactly why each exists.
- Ask what they'd keep if everything changed. Si (the archive) names concrete practices and loyalties with histories.
- Present a bold forecast. Si (the archive) asks what in past experience actually supports it.
Points toward it
- Precise memory for procedural and personal detail
- Visible discomfort at rule-breaking improvisation
- Long-maintained habits and possessions
- Consistently understated speech and presentation
Points away from it
- Bored by repetition, hungry for novelty: suggests Ne (possibility) or Se (present contact)
- Speaks in sweeping future visions: suggests Ni (the long reading)
- Improvises procedures cheerfully: suggests Se (present contact)
In the first person
- “I trust what has already worked: the tested way, the kept record, the standard that survived.”affinity
- “My memory files experience in fine grain: what worked, what failed, what it felt like last time.”affinity
- “I maintain things (habits, tools, relationships, standards) long after others drift.”affinity
- “Before accepting something new, I check it against everything I've already lived.”affinity
- “Discarding a proven way for an untested novelty strikes me as reckless.”aversion
- “I can defend a proven method so rigidly that new possibilities never get considered.”stress
Company: Sigmund Freud · Queen Elizabeth II · George Washington · Gregor Mendel · Jane Austen · Warren Buffett · David Attenborough · Fred Rogers · Irena Sendler · Queen Victoria · Maria Montessori · Rosalind Franklin
Exemplars at this register's extreme: they illustrate the pattern at full strength, not the reader's peer group.