||The Quine-Duhem thesis is a form of the thesis of the underdetermination of theory by empirical evidence. The basic problem is that individual theoretical claims are unable to be confirmed or falsified on their own, in isolation from surrounding hypotheses. For this reason, the acceptance or rejection of a theoretical claim is underdetermined by observation. The thesis can be interpreted in a more radical form that tends to be associated with the epistemic holism of Willard V. O. Quine or in a more restricted form associated with Pierre Duhem. It is primarily an epistemic thesis about the relation between evidence and theory, though in Quine's case it also has semantic overtones connected with his rejection of the analytic-synthetic distinction.