One of the reasons for relativistic attitudes toward science is the impossibility of justifying scientists’ decisions in the face of alternative theories. According to this paper, an alternative theory can challenge scientific rationality only if the conditions of “methodological shortcomings of scientists” and the “existence of alternative theories” are met at a specific time. A commonly used technique to counter relativism is to try to supplement and equip scientists’ methodologies when confronted with alternative theories. However, this paper focuses on evaluating (...) the possibility of “existence an alternative theory.” To this end, by referring to the different definitions of being alternative, we try to show that only “after the decision” and “the conversion of the scientific community” can a theory be considered justifiably “alternative.” Therefore, the relativistic claim is inconsistent because relativists must first accept the validity of scientists’ decisions to attribute being alternative to a theory. In this work, we provide evidence for our claim using a historical example. We also defend conservatism as a corollary of our discussion. (shrink)