Two of the most prominent questions in Kant's critical philosophy concern reason. The first, central to his theoretical philosophy, is the unprovable pretensions of reason in earlier “rationalist” philosophers, especially Leibniz and Descartes. The second, central to his practical philosophy, is the subservient role accorded to reason by the British empiricists—above all Hume, who declared, “Reason is wholly inactive, and can never be the source of so active a principle as conscience, or a sense of morals” (Treatise, 22.214.171.124; see also the entry on rationalism vs. empiricism). Thus the titles of two key works: the monumental Critique of Pure Reason, and the Critique of Practical Reason that is middle point of his great trio of moral writings (between the Groundwork of the Metaphysics of Morals and The Metaphysics of Morals).
Right at the beginning of his exciting new collection of essays, Reason in Philosophy, Robert Brandom announces his allegiance to his own distinctive brand of rationalism: "This book belongs to a venerable tradition that distinguishes us as rational animals, and philosophy by its concern to understand, articulate, and explain the notion of reason that is thereby cast in that crucial demarcating role."(p 1) That is, according to Brandom we are distinguished from other animals by being rational, and the differentia of philosophy as a discipline is that it attempts to comprehend what it is to be rational and to act for reasons in this differentiating way. In the remainder of this remarkably clear and concise collection Prof. Brandom practices philosophy in just this sense. In the various essays Brandom approaches the key notions of rationality, reasons, having a reason, and acting for a reason from a number of different historical and systematic perspectives and tries to articulate and to apply these notions, so articulated, in a variety of different ways. In the process of carrying out these investigations, Brandom also provides us with the most accessible extant introduction to his complex systematic philosophy.
Practical reason is the general human capacity for resolving, through reflection, the question of what one is to do. Deliberation of this kind is practical in at least two senses. First, it is practical in its subject matter, insofar as it is concerned with action. But it is also practical in its consequences or its issue, insofar as reflection about action itself directly moves people to act. Our capacity for deliberative self-determination raises two sets of philosophical problems. First, there are questions about how deliberation can succeed in being practical in its issue. What do we need to assume—both about agents and about the processes of reasoning they engage in—to make sense of the fact that deliberative reflection can directly give rise to action? Can we do justice to this dimension of practical reason while preserving the idea that practical deliberation is genuinely a form of reasoning? Second, there are large issues concerning the content of the standards that are brought to bear in practical reasoning. Which norms for the assessment of action are binding on us as agents? Do these norms provide resources for critical reflection about our ends, or are they exclusively instrumental? Under what conditions do moral norms yield valid standards for reasoning about action? The first set of issues is addressed in sections 1–3 of the present article, while sections 4–5 cover the second set of issues.
Like knowledge, certainty is an epistemic property of beliefs. (In a derivative way, certainty is also an epistemic property of subjects: S is certain that p just in case S's belief that p is certain.) Although some philosophers have thought that there is no difference between knowledge and certainty, it has become increasingly common to distinguish them. On this conception, then, certainty is either the highest form of knowledge or is the only epistemic property superior to knowledge. One of the primary motivations for allowing kinds of knowledge less than certainty is the widespread sense that skeptical arguments are successful in showing that we rarely or never have beliefs that are certain (see Unger 1975 for this kind of skeptical argument) but do not succeed in showing that our beliefs are altogether without epistemic worth (see, for example, Lehrer 1974, Williams 1999, and Feldman 2003; see Fumerton 1995 for an argument that skepticism undermines every epistemic status a belief might have; and see Klein 1981 for the argument that knowledge requires certainty, which we are capable of having).
Hume's position in ethics, which is based on his empiricist theory of the mind, is best known for asserting four theses: (1) Reason alone cannot be a motive to the will, but rather is the “slave of the passions” (see Section 3) (2) Moral distinctions are not derived from reason (see Section 4). (3) Moral distinctions are derived from the moral sentiments: feelings of approval (esteem, praise) and disapproval (blame) felt by spectators who contemplate a character trait or action (see Section 7). (4) While some virtues and vices are natural (see Section 13), others, including justice, are artificial (see Section 9). There is heated debate about what Hume intends by each of these theses and how he argues for them. He articulates and defends them within the broader context of his metaethics and his ethic of virtue and vice.