 Note that the observability of interest is relativized to “us,” the members of the epistemic community whose scientific theories are the topic of interest. Since what counts as observable is relative to what epistemic community the observer is part of, and since the members of that epistemic community are the subject of scientific theory, the constructive empiricist takes what counts as observable as the subject of scientific theory and not something that can be determined a priori (van Fraassen 1980, 56–59). Science itself, then, is ultimately the arbiter of what counts as observable. For worries about circularity in the use of accepted scientific theory to determine which parts of the world are observable (and hence to determine which theories of science are empirically adequate and thereby candidates for acceptance), see Section 3.7 below.