Umwelt

According to Jakob von Uexküll and Thomas A. Sebeok, umwelt (plural: umwelten; the German word Umwelt means "environment" or "surrounding world") is the "biological foundations that lie at the very epicenter of the study of both communication and signification in the human [and non-human] animal." The term is usually translated as "subjective universe". Uexküll theorised that organisms can have different umwelten, even though they share the same environment.

Discussion
Each functional component of an umwelt has a meaning and so represents the organism's model of the world. It is also the semiotic world of the organism, including all the meaningful aspects of the world for any particular organism, i.e. it can be water, food, shelter, potential threats, or points of reference for navigation. An organism creates and reshapes its own umwelt when it interacts with the world. This is termed a 'functional circle'. The umwelt theory states that the mind and the world are inseparable, because it is the mind that interprets the world for the organism. Consequently, the umwelten of different organisms differ, which follows from the individuality and uniqueness of the history of every single organism. When two umwelten interact, this creates a semiosphere.

As a term, umwelt also unites all the semiotic processes of an organism into a whole. Internally, an organism is the sum of its parts operating in functional circles and, to survive, all the parts must work together co-operatively. This is termed the 'collective umwelt' which models the organism as a centralised system from the cellular level upward. This requires the semiosis of any one part to be continuously connected to any other semiosis operating within the same organism. If anything disrupts this process, the organism will not operate efficiently. But, when semiosis operates, the organism exhibits goal-oriented or intentional behaviour.