I would say pink unicorns do not exist at all. The term, for me, describes a concrete entity that does not exist. “The Unicorn” could be type-language, which are abstract objects—like “the Indian Elephant” or “The Higgs Boson” but unlike the Indian Elephant the Unicorn is not something quantified over in zoology and it is hard to think of a useful scientific process which would ever involve an ontological commitment to unicorns (aside from studying the mythology of unicorns which is clearly something quite different). “3 is prime” is a well-formed string in a suitable mathematical model—which is to say a system of manipulating symbols. But this particular method of symbol manipulation is utterly essential to the scientific enterprise and it is trivial to construct methods of symbol manipulation that are not.
Our best scientific theories imply that people can think about pink unicorns as if they were experimental facts. So thoughts about pink unicorns certainly exist. It may also be the case the unicorns possibly exist. But our best scientific theories certainly do not imply the actual existence of unicorns. So pink unicorns do not exist (bracketing modal concerns).
How is it different from “we define stuff we think about that is not found in nature as “abstract”″?
So to conclude: it’s different in that the criterion for existence requires that the entity actually figures in scientific explanation, in our accurate model of the universe, not simply that it is something we can think about.
So, if a theory of pink unicorns was useful to construct an “accurate model of the universe” (presumably not including the part of the universe that is you and me discussing pink unicorns?) these imaginary creatures would be as real as imaginary numbers?
A lot of lifting is being done by “scientific” here. It’s uncontroversial that scientific theories have to be about the real world in some sense, but it doesn’t follow from that that every term mentioned in them successfully refers to something real.
I would say pink unicorns do not exist at all. The term, for me, describes a concrete entity that does not exist. “The Unicorn” could be type-language, which are abstract objects—like “the Indian Elephant” or “The Higgs Boson” but unlike the Indian Elephant the Unicorn is not something quantified over in zoology and it is hard to think of a useful scientific process which would ever involve an ontological commitment to unicorns (aside from studying the mythology of unicorns which is clearly something quite different). “3 is prime” is a well-formed string in a suitable mathematical model—which is to say a system of manipulating symbols. But this particular method of symbol manipulation is utterly essential to the scientific enterprise and it is trivial to construct methods of symbol manipulation that are not.
Our best scientific theories imply that people can think about pink unicorns as if they were experimental facts. So thoughts about pink unicorns certainly exist. It may also be the case the unicorns possibly exist. But our best scientific theories certainly do not imply the actual existence of unicorns. So pink unicorns do not exist (bracketing modal concerns).
So to conclude: it’s different in that the criterion for existence requires that the entity actually figures in scientific explanation, in our accurate model of the universe, not simply that it is something we can think about.
So, if a theory of pink unicorns was useful to construct an “accurate model of the universe” (presumably not including the part of the universe that is you and me discussing pink unicorns?) these imaginary creatures would be as real as imaginary numbers?
Sure! Another way of saying that: If we discovered pink unicorns on another planet they would be as real as imaginary numbers.
A lot of lifting is being done by “scientific” here. It’s uncontroversial that scientific theories have to be about the real world in some sense, but it doesn’t follow from that that every term mentioned in them successfully refers to something real.