Simplicity as a Theoretical Virtue in Science

In the present article, the author tries to study the notion of simplicity, and present some principles and rules relevant to it, such as a priori arguments of rationalists, arguments of empiricists and probabilistic-statistic arguments, as much as possible. He mentions applications of the principle of simplicity in various fields. Nevertheless, he notes that, like many other philosophical principles whose too wide-ranging scope and inclusiveness have led to ambiguity, here seems that many issues and approaches are categorized under a too general term (simplicity). And even sometimes, a single term cannot be applied to them. Yet, in an important part of the article, the author claims that one may always have too simple, but non-accurate and irrelevant to the empirical data, theories. Also, one may always have accurate theories, which costs excess complexity of the theory. Here a question arises: to what degree, should accuracy be forfeited for simplicity?