A Critical Review of Mario Alai’s Solution to the Problemof Underdetermination of Quantum Mechanics Theoriesin Defense of Scientific Realism

Empirical underdetermination is one of the problems that challenges the position of scientific realism regarding the unobservable level of scientific theories. In response to this problem, Mario Alai claims that underdetermination cannot seriously trouble the realist’s position. Like other realists, he introduces theoretical virtues to break the underdetermination and offers special solutions to get rid of the objections to using theoretical virtues. Although Alai believes that theoretical virtues can break the existing underdetermination in most cases, he admits that today, despite using theoretical virtues, the underdetermination between the alternatives of quantum mechanics theories – Standard Quantum Mechanics (SQM) and Bohmian Quantum Mechanics (QBM) – cannot be broken. For this reason, defending the realist position in this special case, he proposes (and brings up) a new solution that pays attention to the unobservable agreements assumed in the ontologies of alternative theories. In this article, by critically examining Mario Alai'’s approach to the problem of empirical underdetermination, it is shown that his solutions to solving the objections of using theoretical virtues are not without difficulties. Also, after examining some similarities of Alai’s new proposed solution to maintain a realist position regarding quantum mechanics theories with the approach of structural realists, it is shown that his solution faces three drawbacks: 1) Reducing alternative theories to each other and dismantling the problem instead of dealing with it, 2) inconsistency and ambiguity in the truth of parts of the agreements of alternative theories, and 3) lack of guarantee in the existence of parts of the agreements, and ineffectiveness to generalize the solution for other possible cases.