Another relevant strand of research is the work on dual-process (or dual-system) theories of decision-making. According to such models, there are two distinct types of mental processes (or systems) that underlie decision-making and agency: one is typically characterized as automatic, effortless, and heuristics-based, and the other as conscious, deliberate, and rule-based. Dual-process models have been deployed widely and successfully in many areas of research (for overviews see Sloman 1996; Evans 2008; for critical reviews see Osman 2004; Keren and Schul 2009). In philosophy, it is commonly assumed, explicitly or implicitly, that there is one mechanism (or faculty) of practical reason that underlies practical reasoning and reason-based agency. This appears to be incompatible with the dual-process framework. What complicates this issue, though, is that there is no consensus on the details of the dual-process model. There is, for instance, no commonly accepted view on how the two processes (or systems) interact. Conscious and deliberate processes may have a top-down influence on automatic processes; the two processes may interact with each other; they may interfere with each other in some cases; there may be cases in which processing switches from one to the other; and so on. Not all of those possibilities are obviously incompatible with the assumption that there is one mechanism (or faculty) of practical reason. Further research is needed in order to investigate whether the two types of processes are in the relevant respects independent or whether they can be construed as interacting parts of one mechanism of decision-making. For a discussion of whether the dual-system framework is compatible with the philosophical standard theory of action see Schlosser 2019.[23]