Intentionality (aboutness as morphism)
Intentionality is τ-categorical aboutness: the directional internal morphism in the Mind-Topos that takes a representation to its intentional object. It is not a mysterious extra relation linking mental content to the world — it is the structured arrow `Int : Rep → Obj` whose composition discipline (sense, reference, attitude) lives entirely within the agent's internal topos.
τ-Definition
Intentionality is τ-categorical aboutness: the directional internal morphism in the Mind-Topos that takes a representation to its intentional object. It is not a mysterious extra relation linking mental content to the world — it is the structured arrow `Int : Rep → Obj` whose composition discipline (sense, reference, attitude) lives entirely within the agent's internal topos.
Categorical invariant. Intentionality = internal morphism Int: Rep → Obj in the Mind-Topos with directional structure and compositional closure (VII.D84). Brentano's mark of the mental is recovered as: every mental state is the codomain of an Int-morphism.
Primary registry anchor:
VII.D84
τ-Derivation Chain
-
I.K0— Universe Postulate -
VII.D82— Mind as Internal Topos — carrier for representations and inferences -
VII.T39— Mind-Topos Structure Theorem — internal logic, beliefs as sections -
VII.D84— Intentionality as Morphism — aboutness with directional structure and compositional closure
Lean modules referenced:
TauLib.BookVII.Logos.Sector
Phenomenological Correlate
Intentionality is instantiated whenever a mental state is *about* something — a perception of an apple, a belief about Vienna, a desire for rest, a fear of falling. The aboutness is not added to the mental state from outside; it is the directional morphism that constitutes that state's content.
Examples:
- Belief that water is H₂O — Int-morphism from belief-token to chemical-structure object
- Desire for coffee — Int-morphism from desire-state to a not-yet-actualized object
- Fear of an unsigned letter — Int-morphism whose codomain is a fictional/non-existent object (still well-typed inside the topos)
- Sense vs reference (Frege): two distinct Int-morphisms with overlapping codomains — same object, different presentation arrows
Register codomain: Reg_E primarily (Int-morphisms ground belief content read as Obs), but every register can be the readout for an Int-image — Reg_P reads desires/intentions, Reg_C reads stance-directed acts.
Manuscript reference: manuscript-sources/book-07/part09/ch109.tex
Lean Coverage
Status: Formalized
Module: TauLib.BookVII.Logos.Sector
Lean kind: def
Lean symbol: Tau.BookVII.Logos.Sector.IntentionalityAsMorphism