Jacob von Uexküll was an Estonian biologist, who among other things coined the term “Umwelt” to denote the sensory and cognitive world of a particular species. The idea has been unjustly ignored by philosophers of biology, in part because it was enthusiastically taken up by semioticians instead, in part because of his treatment of “meaning” in biology. But it is a useful distinction.
Umwelt, which literally means “environment” or “surrounding world”, are those aspects of the environment to which animals respond. His case study is the tick (a tick, actually; there are lots of them):
“…this eyeless animal finds the way to her watchpoint [at the top of a tall blade of grass] with the help of only its skin’s general sensitivity to light. The approach of her prey becomes apparent to this blind and deaf bandit only through her sense of smell. The odor of butyric acid, which emanates from the sebaceous follicles of all mammals, works on the tick as a signal that causes her to abandon her post (on top of the blade of grass/bush) and fall blindly downward toward her prey. If she is fortunate enough to fall on something warm (which she perceives by means of an organ sensible to a precise temperature) then she has attained her prey, the warm-blooded animal, and thereafter needs only the help of her sense of touch to find the least hairy spot possible and embed herself up to her head in the cutaneous tissue of her prey. She can now slowly suck up a stream of warm blood.”
For him, the Umwelt of the tick is the odor of butyric acid, which emanates from the sebaceous follicles of all mammals, the temperature of 37 degrees celsius (corresponding to the blood of all mammals), and the hairy typology of mammals (according to Wikipedia). These three aspects of the tick’s environment are all it needs to sense.
His book Forays into the worlds of animals and humans has been translated, and is now published by University of Minnesota Press. I look forward to getting a complimentary copy <grin>. [H/T Roberta Millstein]
Paul Griffiths and I believe that the world of human “common sense” is the Umwelt of primates; all the things we need to negotiate to survive, mate and reproduce are the objects that common sense indicates are there, and we can tradeoff Type I (false positives) from Type II (false negatives) errors in order to do so without serious trouble. The way we perceive the world begins (but does not end!) with our shared primate Umwelt.