Michael Huemer

The brain-in-a-vat argument for skepticism is best formulated, not using the closure principle, but using the “Preference Principle,” which states that in order to be justified in believing H on the basis of E, one must have grounds for preferring H over each alternative explanation of E. When the argument is formulated this way, Dretske’s and Klein’s responses to it fail. However, the strengthened argument can be refuted using a direct realist account of perception. For the direct realist, refuting the SIV scenario is not a precondition on knowledge of the external world, and only the direct realist can give a non-circular account of how we know we’re not brains in vats

Informal student evaluations of faculty were started in the 1960's by enterprising college students.(1) Since then, their use has spread so that now they are administered in almost all American colleges and universities and are probably the main source of information used for evaluating faculty teaching performance.(2) There is an enormous literature on the subject of student evaluations of faculty (SEF).(3) The following is a summary of some developments in that literature that should be of special interest to faculty, with particular emphasis on criticisms of SEF that have emerged recently. But I begin with the arguments in favor of the use of SEF.

I defend the 'Repugnant' Conclusion that for any possible population of happy people, a population containing a sufficient number of people with lives barely worth living would be better. Four lines of argument converge on this conclusion, and the conclusion has a simple, natural theoretical explanation. The opposition to the Repugnant Conclusion rests on a bare appeal to intuition. This intuition is open to charges of being influenced by multiple distorting factors. Several theories of population ethics have been devised to avoid the Repugnant Conclusion, but each generates even more counterintuitive consequences. The intuition opposing the Repugnant Conclusion is thus among the best candidates for an intuition that should be revised

In the practice of jury nullification, a jury votes to acquit a defendant in disregard of the factual evidence, on the grounds that a conviction would result in injustice, either because the law itself is unjust or because its application in the particular case would be unjust. Though the practice is widely condemned by courts, the arguments against jury nullification are surprisingly weak. I argue that, pursuant to the general ethical duty to avoid causing unjust harms to others, jurors are often morally obligated to disregard the law.

I defend the principle of Phenomenal Conservatism, on which appearances of all kinds generate at least some justification for belief. I argue that there is no reason for privileging introspection or intuition over perceptual experience as a source of justified belief; that those who deny Phenomenal Conservatism are in a self-defeating position, in that their view cannot be both true and justified; and that thedemand for a metajustification for Phenomenal Conservatism either is an easily met demand, or is an unfair or question-begging one.

Externalist theories of justification create the possibility of cases in which everything appears to one relevantly similar with respect to two propositions, yet one proposition is justified while the other is not. Internalists find this difficult to accept, because it seems irrational in such a case to affirm one proposition and not the other. The underlying internalist intuition supports a specific internalist theory, Phenomenal Conservatism, on which epistemic justification is conferred by appearances.

Some theories of practical reasons incorporate a lexical priority structure, according to which some practical reasons have infinitely greater weight than others. This includes absolute deontological theories and axiological theories that take some goods to be categorically superior to others. These theories face problems involving cases in which there is a non-extreme probability that a given reason applies. In view of such cases, lexical-priority theories are in danger of becoming irrelevant to decision-making, becoming absurdly demanding, or generating paradoxical cases in which each of a pair of actions is permissible yet the pair is impermissible.

Richard Fumerton’s “Principle of Inferential Justification” holds that, in order to be justified in believing P on the basis of E, one must be justified in believing that E makes P probable. I argue that the plausibility of this principle rests upon two kinds of mistakes: first, a level confusion; and second, a fallacy of misconditionalisation. Furthermore, Fumerton’s principle leads to skepticism about inferential justification, for which reason it should be rejected. Instead, the examples Fumerton uses to motivate his principle can be accounted for using a different principle: in order for S to be justified in believing P on the basis of E, it must be true that E makes P probable. The latter principle can be independently motivated and does not lead to skepticism

Skeptical hypotheses such as the brain-in-a-vat hypothesis provide extremely poor explanations for our sensory experiences. Because these scenarios accommodate virtually any possible set of evidence, the probability of any given set of evidence on the skeptical scenario is near zero; hence, on Bayesian grounds, the scenario is not well supported by the evidence. By contrast, serious theories make reasonably specific predictions about the evidence and are then well supported when these predictions are satisfied

Should the recreational use of drugs such as marijuana, cocaine, heroin, and LSD, be prohibited by law? Prohibitionists answer yes. They usually argue that drug use is extremely harmful both to drug users and to society in general, and possibly even immoral, and they believe that these facts provide sufficient reasons for prohibition. Legalizers answer no. They usually give one or more of three arguments: First, some argue that drug use is not as harmful as prohibitionists believe, and even that it is sometimes beneficial. Second, some argue that drug prohibition “does not work”, i.e., is not very successful in preventing drug use and/or has a number of very bad consequences. Lastly, some argue that drug prohibition is unjust or violates rights. I won’t attempt to discuss all these arguments here. Instead, I will focus on what seem to me the three most prominent arguments in the drug legalization debate: first, the argument that drugs should be outlawed because of the harm they cause to drug users; second, the argument that they should be outlawed because they harm people other than the user; and third, the argument that drugs should be legalized because drug prohibition violates rights. I shall focus on the moral/philosophical issues that these [134] arguments raise, rather than medical or sociological issues. I shall show that the two arguments for prohibition fail, while the third argument, for legalization, succeeds.

Ethical naturalists interpret moral knowledge as analogous to scientific knowledge and not dependent on intuition. For their account to succeed, moral truths must explain observable phenomena, and these explanations (i) must be better than any explanations framed in non-moral terms, (ii) must not rely on ad hoc posits about the causal powers of moral properties, and (iii) must not presuppose the existence of an independent means of awareness of moral truths. No moral explanations satisfy these criteria.