Jakob von Uexküll

Estonian-German biologist who developed the concept of Umwelt — the subjective perceptual world of each organism — founding the field of biosemiotics.

Umwelt: each organism has its own subjective world (Umwelt) constituted by the signs it can perceive and act upon — there is no single, objective environment but as many environments as there are organisms. Functional circle: organism and environment are mutually constitutive — the organism's body shapes what it perceives, and what it perceives shapes its actions. Fundamental influence on Heidegger, Merleau-Ponty, and biosemiotics.