Sergio Tenenbaum

Subjectivism is the mainstream view of practical reason. According to subjectivism, what has value for an agent must ultimately be grounded in what the agent actually desires. Subjectivism is motivated by a conservative view of the scope and extent of practical reason. Against this view, my dissertation argues that any coherent conception of an end must endow practical reason with a scope that goes beyond anything that subjectivism could accommodate. ;Subjectivism correctly grasps that nothing can count as an end for an agent if she is incapable of recognizing it as such; value cannot exist independently of our capacity to appreciate it. I argue that the right conclusion to draw from this is that practical reason constitutes its own object by properly judging on practical matters. The grounds for taking a certain object to bear value lie not in the attributes of a certain object but in the nature of the activity of pursuing ends. According to the concept of practical reason I defend in this dissertation, which I call "the constitutive conception of practical reason", practical reason must set its objects from its own resources rather than find them in an external reality. ;But if practical reason does not track any independently existing objects, how can we distinguish between correct and incorrect judgements? It seems that this conception faces a dilemma: Either the activity of reason is merely a source of formal constraints, or it is an arbitrary, ungrounded exercise. I argue that this dilemma gets its grip on us only from an illegitimate separation of the rational and non-rational parts of human nature. This separation leads us to to think of our cognitive and conative powers as independent. However, the proper understanding of practical reason requires us to see our desires, emotions, etc. as presenting us with appearances of the good, as providing perspectives on something which we represent as the proper object of our pursuit. In forming an overarching conception of the good by reflectively assessing the claims of these different perspectives, practical reason sets its object.

This paper argues that the principles of instrumental rationality apply primarily to extended action through time. Most philosophers assume that rational requirements and principles govern in the first instance momentary mental states, as opposed to governing extended intentional actions directly. In the case of instrumental rationality, the relevant mental states or attitudes would typically be preferences, decisions, or intentions. In fact, even those who recognize the extended nature of our agency still assume that rational requirements apply primarily to mental states at a moment in time. Such views try to do justice to the extended nature of our agency by postulating rational requirements that apply in the first instance to plans, policies, and intentions more generally. The paper focuses on the central case of requirements and reasons governing the reconsideration of intentions and argues that these requirements or reasons are either superfluous or invalid.I argue that a proper conception of instrumental reasoning that applies directly to actions turn out to have surprising consequences. In fact, this conception allows us to see that policies, projects and the like are best understood as instances of extended actions, and that the instrumental requirements that apply to projects and policies are exactly the same as the instrumental requirements that apply to ordinary extended actions. Finally, I argue that the resulting theory of instrumental rationality is a significant improvement over theories that rely on principles governing intentions.