Jakob von Uexküll

Von Uexküll worked in the generation after Haeckel and in a tradition that was simultaneously ecological and phenomenological. His 1934 A Foray into the Worlds of Animals and Humans introduced the tick example that has become standard in philosophy of biology: the organism that perceives three things (scent of butyric acid, temperature of mammalian blood, texture of skin) and for which the rest of the world does not exist. The Umwelt concept made precise Haeckel's insight that organism and environment are locked in a single relational system by specifying the relationship phenomenologically: the environment is not an objective given but a construction of the organism's perceptual architecture. The concept has been rediscovered by phenomenologists, biosemioticians, and—most recently—by philosophers trying to articulate what machine perception is and is not.