  While the philosophical literature has extensively studied how decisions
relate to arguments, reasons and justifications, decision theory almost
entirely ignores the latter notions and rather focuses on preference and
belief. In this article, we argue that decision theory can largely benefit from
explicitly taking into account the stance that decision-makers take towards
arguments and counter-arguments. To that end, we elaborate a formal framework
aiming to integrate the role of arguments and argumentation in decision theory
and decision aid. We start from a decision situation, where an individual
requests decision support. In this context, we formally define, as a
commendable basis for decision-aid, this individual's deliberated judgment,
popularized by Rawls. We explain how models of deliberated judgment can be
validated empirically. We then identify conditions upon which the existence of
a valid model can be taken for granted, and analyze how these conditions can be
relaxed. We then explore the significance of our proposed framework for
decision aiding practice. We argue that our concept of deliberated judgment
owes its normative credentials both to its normative foundations (the idea of
rationality based on arguments) and to its reference to empirical reality (the
stance that real, empirical individuals hold towards arguments and
counter-arguments, on due reflection). We then highlight that our framework
opens promising avenues for future research involving both philosophical and
decision theoretic approaches, as well as empirical implementations.
