Editing Unobservable (section)

== Philosophy of science ==
The [[ontology|ontological nature]] and [[epistemology|epistemological]] issues concerning unobservables are central topics in philosophy of science. The theory that unobservables posited by scientific theories exist is referred to as [[scientific realism]]. It contrasts with [[instrumentalism]], which asserts that we should withhold [[ontological commitment]]s to unobservables even though it is useful for scientific theories to refer to them.

The notion of observability plays a central role in [[constructive empiricism]]. According to [[Bas van Fraassen]], the goal of scientific theories is not truth about all entities but only truth about all observable entities.<ref>{{cite book |last1=Monton |first1=Bradley |last2=Mohler |first2=Chad |author1-link=:fi:Bradley Monton|title=Constructive Empiricism |url=https://plato.stanford.edu/archives/sum2017/entries/constructive-empiricism/|publisher=[[Stanford Encyclopedia of Philosophy]] (Summer 2017 Edition)|date=2017 }}</ref> If a theory is true in this restricted sense, it is called an ''empirically adequate'' theory. Van Fraassen characterizes observability counterfactually: "X is observable if there are circumstances which are such that, if X is present to us under those circumstances, then we observe it".<ref name="Fraassen">{{cite book |last=van Fraassen |first=Bas |authorlink=Bas van Fraassen|title=The Scientific Image |publisher=Oxford University Press |date=1980 |pages=16–17}}</ref>

A problem with this and similar characterizations is to determine the exact extension of what is unobservable. There is little controversy that regular everyday objects that we can perceive without any aids are observable. Such objects include, for example, trees, chairs, or dogs. But controversy starts with cases where unaided perception fails. These include using telescopes to study distant galaxies,<ref>{{cite book |editor-last1=Churchland |editor-first1=Paul M. |authorlink=Paul Churchland |editor-last2=Hooker |editor-first2=Clifford A. |title=Images of Science: Essays on Realism and Empiricism |last=Churchland |first=Paul M. |chapter=The Ontological Status of Observables: In Praise of the Superempirical Virtues |publisher=University of Chicago Press |date=1985}}</ref> using microscopes to study bacteria, or using cloud chambers to study positrons.<ref name="Fraassen" />

Some philosophers have been motivated by these and similar examples to question the value of the distinction between observable and unobservable in general.<ref>{{cite journal |last=Hacking |first=Ian |title=Do We See through a Microscope? |journal=Pacific Philosophical Quarterly |volume=62 |issue=4 |date=1981|pages=305–322 |doi=10.1111/j.1468-0114.1981.tb00070.x |url=https://philarchive.org/rec/HACDWS }}</ref>