present evidence); rather, we cannot know if they are correct. Philosophy of science In the philosophy of science, underdetermination is often presented as a problem for scientific realism, which holds that we have reason to believe in entities that are not directly observable talked about by scientific theories. One such argument proceeds as follows (to be compared to the previous one): All the available observational evidence for such entities underdetermines the claims of a scientific theory about such entities. Only the observational evidence is relevant to believing a scientific theory. Therefore, there is no evidence for believing what scientific theories say about such entities. Particular responses to this argument attack both the first and the second premise (1 and 2). It is argued against the first premise that the underdetermination must be strong and/or inductive. It is argued against the second premise that there is evidence for a theory's truth besides observations; for example, it is argued that simplicity, explanatory power or some other feature of a theory is evidence for it over its rivals. A more general response from the scientific realist is to argue that underdetermination is no special problem for science, because, as indicated earlier in this article, all knowledge that is directly or indirectly supported by evidence suffers from it—for example, conjectures concerning unobserved observables. It is therefore too powerful an argument to have any significance in the philosophy of science, since it does not cast doubt uniquely on conjectured unobservables. See also Poverty of the stimulus Reference class problem Scientific method Instrumentalism Confirmation holism Equifinality Metaphysics Occam's razor Observational equivalence Overdetermination Notes and references External links Underdetermination and the Claims of Science by P. D. Magnus Epistemology Philosophy of science Evidence