Michael Huemer

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.

Recent results in probability theory have cast doubt on coherentism, purportedly showing (a) that coherence among a set of beliefs cannot raise their probability unless individual beliefs have some independent credibility, and (b) that no possible measure of coherence makes coherence generally probability-enhancing. I argue that coherentists can reject assumptions on which these theorems depend, and I derive a general condition under which the concurrence of two information sources lacking individual credibility can raise the probability of what they report.

Individuals have a prima facie right to own firearms. This right is significant in view both of the role that such ownership plays in the lives of firearms enthusiasts and of the self-defense value of firearms. Nor is this right overridden by the social harms of private gun ownership. These harms have been greatly exaggerated and are probably considerably smaller than the benefits of private gun ownership. And I argue that the harms would have to be at least several times greater than the benefits in order to render gun prohibition permissible.

Sense data are the alleged mind-dependent objects that we are directly aware of in perception, and that have exactly the properties they appear to have. For instance, sense data theorists say that, upon viewing a tomato in normal conditions, one forms an image of the tomato in one's mind. This image is red and round. The mental image is an example of a “sense datum.” Many philosophers have rejected the notion of sense data, either because they believe that perception gives us direct awareness of physical phenomena, rather than mere mental images, or because they believe that the mental phenomena involved in perception do not have the properties that appear to us (for instance, I might have a visual experience representing a red, round tomato, but my experience is not itself red or round). Defenders of sense data have argued, among other things, that sense data are required to explain such phenomena as perspectival variation, illusion, and hallucination. Critics of sense data have objected to the theory's commitment to mind-body dualism, the problems it raises for our knowledge of the external world, its difficulty in locating sense data in physical space, and its apparent commitment to the existence of objects with indeterminate properties

Trenton Merricks argues that on any reasonable account, warrant must entailtruth. I demonstrate three theses about the properties ofwarrant: (1) Warrant is not unique;there are many properties that satisfy the definition of warrant. (2) Warrant need not entail truth; there are some warrant properties that entailtruthand others that do not. (3) Warrant need not be closed under entailment, even if knowledge is. If knowledge satisfies closure, then some warrant properties satisfy closure while others do not;if knowledge violates closure, then allwarrant properties violate closure.

People want things, and they tend to act in such a way as to get the things they want, to the best of their ability.1 Sometimes our wants conflict with each other, so that we are forced to choose between different things that we want. When this happens, we normally choose the thing that we want more, over the thing that we want less. Behaving in this way is what we call “rational”; more specifically, it is “instrumentally rational.” Instrumental rationality consists in choosing the means that best achieves one’s goals, according to the information one has.

A central problem facing a probabilistic approach to the problem of induction is the difficulty of sufficiently constraining prior probabilities so as to yield the conclusion that induction is cogent. The Principle of Indifference, according to which alternatives are equiprobable when one has no grounds for preferring one over another, represents one way of addressing this problem; however, the Principle faces the well-known problem that multiple interpretations of it are possible, leading to incompatible conclusions. I propose a partial solution to the latter problem, drawing on the notion of explanatory priority. The resulting synthesis of Bayesian and inference-to-best-explanation approaches affords a principled defense of prior probability distributions that support induction

Debunking skeptics claim that our moral beliefs are formed by processes unsuited to identifying objective facts, such as emotions inculcated by our genes and culture; therefore, they say, even if there are objective moral facts, we probably don’t know them. I argue that the debunking skeptics cannot explain the pervasive trend toward liberalization of values over human history, and that the best explanation is the realist’s: humanity is becoming increasingly liberal because liberalism is the objectively correct moral stance.

In The Structure of Empirical Knowledge , Laurence BonJour argues that coherence among a set of empirical beliefs can provide justification for those beliefs, in the sense of rendering them likely to be true. He also repudiates all forms of foundationalism for empirical beliefs, including what he calls "weak foundationalism" (the weakest form of foundationalism he can find). In the following, I will argue that coherence cannot provide any justification for our beliefs in the manner BonJour suggests unless some form of foundational justification is assumed. In other words, the argument that BonJour gives in favor of the thesis that coherence provides a kind of justification succeeds if and only if some beliefs have (at least weak) foundational justification.

Parsimony is a virtue of empirical theories. Is it also a virtue of philosophical theories? I review four contemporary accounts of the virtue of parsimony in empirical theorizing, and consider how each might apply to two prominent appeals to parsimony in the philosophical literature, those made on behalf of physicalism and on behalf of nominalism. None of the accounts of the virtue of parsimony extends naturally to either of these philosophical cases. This suggests that in typical philosophical contexts, ontological simplicity has no evidential value.

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. The practice is widely condemned by courts, which strenuously attempt to prevent it. Nevertheless, 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. (~7400 words)