Michael Huemer

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.

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)

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.

Recent results in probability theory have cast doubt on the coherence theory of justification, allegedly showing that coherence cannot produce justification for beliefs in the absence of foundational justification, and that there can be no measure of coherence on which coherence is generally truth-conducive. I argue that the coherentist can reject some of the assumptions on which these theorems depend. Coherence can then be held to produce justification on its own, and truth-conducive measures of coherence can be constructed.

The _minimal free will thesis_ (MFT) holds that at least some of the time, someone has more than one course of action that he can perform. ⁽¹⁾ This is the least that must be true in order for it to be said that there is free will. It may be disputed whether the truth of MFT is _sufficient_ for us to 'have free will,' ⁽²⁾ but there is no doubt that the main philosophical challenge to the belief in free will has come from the thesis of universal determinism, so understood as to exclude MFT. A proof of MFT is therefore of considerable philosophical interest, whether or not it constitutes a full proof of free will. In any case, it is the minimal free will thesis of which I have a proof to offer.

Michael Huemer argues that there is a tension between two principles putatively essential to Rand's ethics: the principle of egoism, which states that the only reason for doing (or not doing) anything is that it will serve (or frustrate) one's own interests; and the principle that one must not sacrifice others. Huemer considers several arguments that Rand offers for the second principle but finds that each involves either implausible empirical assumptions or assumptions that conflict with egoism. Huemer suggests that Rand may not be an egoist in the usual sense; her positions are much more consistent with the second principle.

Illegal drugs are not inherently unclean, any more than alcohol, tobacco, or canola oil. All of these are simply chemicals that people choose to ingest for enjoyment, and that can harm our health if used to excess. Most of the sordid associations we have with illegal drugs are actually the product of the drug laws: it is because of the laws that drugs are sold on the black market, that Latin American crime bosses are made rich, that government officials are corrupted, and that drug users rob others to buy drugs.