Acceptance of no theory is justified in science An Argument against Scientific Realism

As a theory about science, scientific realism has taken various forms; according to one of the most popular from among them, this theory is, as a matter of fact, a claim concerning the goal of science. According to this approach, for the realist, the goal of science is truth; and the correct way to accept a theory is to believe in its truth. In this article, the author seeks to show that scientific realism comes to the conclusion that "acceptance of no theory is justified in science". And this cannot be accepted, in particular, if it is a conclusion of a theory which claims for closeness to conventional understanding; and as a result, this may be taken as a basis for an argument against scientific realism. To show that scientific realism comes to such a conclusion, one has to explore concepts such as "justification", "acceptance", and theory, in details; and to provide an understanding of them, which is, firstly, defendable and discussable in the philosophy of science; and secondly, consistent with scientific realism against which she/he is supposed to argue. Accordingly, a part of this article has been devoted to analyze such concepts, and in particular concepts of "justification" and "acceptance". In what follows, having introduced the concept of practical justification, the author proceeds to show that acceptance of theories is practically justified; and even, the necessary condition for each and any purposeful and rational act is to appeal to theories. It is evident, however, that in real situations, one has to select from among competitive theories; and to do so she/he needs some criteria. As criteria of selection, philosophers of science have proposed more and less similar advantages. In the last part of the article, a list of such advantages will be provided. It should be noted that this advantages, when recommend to not accept a theory, are in line with our epistemic tasks; when they recommend to accept a theory, however, they are only practically justified.