Scientists have three options when a conflict arises between observation and hypotheses: reject the hypothesis, reject the observation, or accept both by proposing an auxiliary hypothesis. A rationalist believes that well-established scientific theories should not be abandoned lightly due to anomalous evidence, while an empiricist believes theories should be rejected if contradicted by evidence. For example, when Uranus's orbit didn't match predictions, scientists proposed the auxiliary hypothesis of an unknown planet rather than rejecting Newtonian physics. This illustrates the rationalist view that outstanding problems in a generally successful theory will eventually be resolved.