Short definition

An idea a person recognizes as structuring for their way of seeing, and wants to hold inside themselves rather than filed away somewhere. It is owned as personal, and it is provisional without being weak.

Synonyms and variants

Strong conviction, structuring idea, core of thought (for the set they form).

Not to be confused with

• Flash card — the brief support that carries a pillar and serves to hold it in active memory; a material object where the pillar is a content.
• Principle — a rule of action stated to be applied, often shared by a group; the pillar prescribes nothing and commits only the person who recognizes it.
• Established truth — a proposition held to be true independently of who states it; a pillar is a strong conviction, not a fixed truth.

Examples

A sentence read in an article that gives the impression of recognizing something — "that's it" — and that continues, months later, to shape the way you look at a professional situation.

Ambiguities / debates

The tension is in the word itself: a pillar evokes the definitive, whereas the use retained here allows it to be provisional. That is owned — the solidity referred to is that of the support it provides today, not that of its duration.