Joshua Knobe

Recent developments in cosmology indicate that every history having a non-zero probability is realized in infinitely many distinct regions of spacetime. Thus, it appears that the universe contains infinitely many civilizations exactly like our own, as well as infinitely many civilizations that differ from our own in any way permitted by physical laws. We explore the implications of this conclusion for ethical theory and for the doomsday argument. In the infinite universe, we find that the doomsday argument applies only to effects which change the average lifetime of all civilizations, and not those which affect our civilization alone.

A growing body of research has examined how people judge the persistence of identity over time—that is, how they decide that a particular individual is the same entity from one time to the next. While a great deal of progress has been made in understanding the types of features that people typically consider when making such judgments, to date, existing work has not explored how these judgments may be shaped by normative considerations. The present studies demonstrate that normative beliefs do appear to play an important role in people's beliefs about persistence. Specifically, people are more likely to judge that the identity of a given entity remains the same when its features improve than when its features deteriorate. Study 1 provides a basic demonstration of this effect. Study 2 shows that this effect is moderated by individual differences in normative beliefs. Study 3 examines the underlying mechanism, which is the belief that, in general, various entities are essentially good. Study 4 directly manipulates beliefs about essence to show that the positivity bias regarding essences is causally responsible for the effect

Since the earliest days of analytic philosophy, it has been a common practice to appeal to intuitions about particular cases. Typically, the philosopher presents a hypothetical situation and then makes a claim of the form: ‘In this case, we would surely say....’ This claim about people’s intuitions then forms a part of an argument for some more general theory about the nature of our concepts or our use of language. One puzzling aspect of this practice is that it so rarely makes use of standard empirical methods. Although philosophers quite frequently make claims about ‘what people would ordinarily say,’ they rarely back up those claims by actually asking people and looking for patterns in their responses. In recent years, however, a number of philosophers have tried to put claims about intuitions to the test, using experimental methods to figure out what people really think about particular hypothetical cases. At times, the results have been extremely surprising. Here I discuss applications of this new methodology to three areas of philosophy — the philosophy of language, the theory of action, and the free will debate

Contemporary moral psychology has been dominated by two broad traditions, one usually associated with Aristotle, the other with Kant. The broadly Aristotelian approach emphasizes the role of childhood upbringing in the development of good moral character, and the role of such character in ethical behavior. The broadly Kantian approach emphasizes the role of freely chosen conscious moral principles in ethical behavior. We review a growing body of experimental evidence that suggests that both of these approaches are predicated on an implausible view of human psychology. This evidence suggests that both childhood upbringing and conscious moral principles have extraordinarily little impact on people's moral behavior. This paper argues that moral psychology needs to take seriously a third approach, derived from Nietzsche. This approach emphasizes the role of heritable psychological and physiological traits in explaining behavior. In particular, it claims that differences in the degree to which different individuals behave morally can often be traced back to heritable differences between those individuals. We show that this third approach enjoys considerable empirical support - indeed that it is far better supported by the empirical data than are either the Aristotelian or Kantian traditions in moral psychology.

The psychological study of ethical reasoning tends to concentrate on a few specific issues, with the bulk of the research going to the study of people's attitudes toward moral rules or the welfare of others. But people's ethical reasoning is also shaped by a wide range of other concerns. Here I focus on the importance that people attach to the ideal of being yourself. It is shown that certain experimental results - results that seemed anomalous and inexplicable to researchers who focused on moral rules and concern for the welfare of others - can be explained quite elegantly as the product of people's attachment to the ideal of 'being yourself'. The success of this explanation then points to the need for a more general inquiry into the role that the ideal of 'being yourself ' plays in people's ethical reasoning.