Gilbert Harman

Change in View offers an entirely original approach to the philosophical study of reasoning by identifying principles of reasoning with principles for revising one's beliefs and intentions and not with principles of logic. This crucial observation leads to a number of important and interesting consequences that impinge on psychology and artificial intelligence as well as on various branches of philosophy, from epistemology to ethics and action theory. Gilbert Harman is Professor of Philosophy at Princeton University. A Bradford Book.

The first part of this article discusses recent skepticism about character traits. The second describes various forms of virtue ethics as reactions to such skepticism. The philosopher J.-P. Sartre argued in the 1940s that character traits are pretenses, a view that the sociologist E. Goffman elaborated in the 1950s. Since then social psychologists have shown that attributions of character traits tend to be inaccurate through the ignoring of situational factors. (Personality psychology has tended to concentrate on people's conceptions of personality and character rather than on the accuracy of these conceptions). Similarly, the political theorist R. Hardin has argued for situational explanations of bloody social disputes in the former Yugoslavia and in Africa, rather than explanations in terms of ethnic hatred for example. A version of virtue ethics might identify virtues as characteristics of acts rather than character traits, as traits consisting in actual regularities in behavior, or as robust dispositions that would manifest themselves also in counterfactual situations

This volume is a direct result of a conference held at Princeton University to honor George A. Miller, an extraordinary psychologist. A distinguished panel of speakers from various disciplines -- psychology, philosophy, neuroscience and artificial intelligence -- were challenged to respond to Dr. Miller's query: "What has happened to cognition? In other words, what has the past 30 years contributed to our understanding of the mind? Do we really know anything that wasn't already clear to William James?" Each participant tried to stand back a little from his or her most recent work, but to address the general question from his or her particular standpoint. The chapters in the present volume derive from that occasion.

Putnam rejects "metaphysical realism," which takes "the world" to be a single complex thing, a connected causal or explanatory order into which all facts fit. he argues that such metaphysical realism is responsible for views he finds implausible; in particular, it can lead to moral relativism when one tries to locate the place of value in the world of fact. i agree that metaphysical realism will lead a thoughtful philosopher to moral relativism, but find neither of these views implausible. in particular, putnam's main argument against metaphysical realism seems fallacious and his suggested alternative, to think of truth as the idea limit of rational inquiry, is clearly incorrect.

Harman distinguishes between two uses of the term “logic”: as referring either to the theory of implication or to the theory of reasoning, which are quite distinct. His interest here is reasoning: a process that can modify intentions and beliefs. To a first approximation, theoretical reasoning is concerned with what to believe and practical reasoning is concerned with what to intend to do, although it is possible to have practical reasons to believe something. Practical considerations are relevant to whether to engage in theoretical inquiry into a given question, the extent of time and other resources to devote to such inquiry, and whether and when to end such inquiry. Simplicity and conservatism play a role in theoretical reasoning that can be given a practical justification without allowing wishful thinking into theoretical reasoning, a justification that can also be given a non-practical interpretation.

In _Reliable Reasoning_, Gilbert Harman and Sanjeev Kulkarni -- a philosopher and an engineer -- argue that philosophy and cognitive science can benefit from statistical learning theory (SLT), the theory that lies behind recent advances in machine learning. The philosophical problem of induction, for example, is in part about the reliability of inductive reasoning, where the reliability of a method is measured by its statistically expected percentage of errors -- a central topic in SLT. After discussing philosophical attempts to evade the problem of induction, Harman and Kulkarni provide an admirably clear account of the basic framework of SLT and its implications for inductive reasoning. They explain the Vapnik-Chervonenkis (VC) dimension of a set of hypotheses and distinguish two kinds of inductive reasoning. The authors discuss various topics in machine learning, including nearest-neighbor methods, neural networks, and support vector machines. Finally, they describe transductive reasoning and suggest possible new models of human reasoning suggested by developments in SLT.

There has been considerable controversy about whether this last entailment always holds. Ordinary subjects may judge that (4) and (5) are appropriate in cases in which none of (1)-(3) are—cases in which Jack’s breaking the base is a foreseen but undesired consequence of Jack’s intentionally doing something else. It is currently debated what the best explanation of such ordinary reactions might be. It is also debated what to make of the fact that ordinary judgments using the adjective intentional or the adverb intentionally seem influenced by normative considerations.

I begin by describing my relation with Nicholas Sturgeon and his objections to things I have said about moral explanations. Then I turn to issues about moral relativism. One of these is whether a plausible version of moral relativism can be formulated as a claim about the logical form of certain moral judgments. I agree that is not a good way to think of moral relativism. Instead, I think of moral relativism as a version of moral realism. I compare moral relativism with the relativity of motion and with the relativity of language. Moralities are real in a way that is similar to the way that languages are real. Next I discuss resemblances between nonhuman animal behavior and human behavior having to do with language or communication and with moral or proto-moral behavior. However, I am more interested in aspects of language and morality that are not found in nonhuman animals, aspects that appear to depend on a kind of recursive structure in human language and morality but not in animals. This leads me to argue that aspects of moral theory might benefit from a comparison with certain aspects of linguistic theory. Another comparison is between moralities and legal systems: I speculate that the content of legal and moral systems is influenced by legal and moral bargaining