Jakob von Uexküll, 1934. German for “surrounding-world.”
An organism’s subjective perceptual world — the subset of reality its senses can detect, shaped into a functional loop: stimulus, internal processing, action.
Organisms don’t perceive objective reality. They perceive what their sensory organs allow, nothing more.
The tick’s world
A tick perceives three things:
- Butyric acid (mammal skin oil) — drop from the grass
- 37°C warmth (blood temperature) — confirms landing
- Hairless texture (skin surface) — guides the bite
No sight. No hearing. No taste. Three signals constitute the tick’s entire world. From outside, this looks impoverished. From the tick’s position, there is no impoverishment — this is the world.
Three distinctions
| Term | Meaning |
|---|---|
| Umgebung | External environment (what instruments measure) |
| Umwelt | Subjective experienced world (what the organism perceives) |
| Innenwelt | Internal map linking perception to action |
Two organisms in the same Umgebung can inhabit radically different Umwelten. A dog and a tick share a meadow but live in different worlds.
Source: Jakob von Uexküll, A Foray into the Worlds of Animals and Humans (1934)