Kevin Tobia

Our aim in this entry is to articulate the state of the art in the moral psychology of personal identity. We begin by discussing the major philosophical theories of personal identity, including their shortcomings. We then turn to recent psychological work on personal identity and the self, investigations that often illuminate our person-related normative concerns. We conclude by discussing the implications of this psychological work for some contemporary philosophical theories and suggesting fruitful areas for future work on personal identity.

Phineas Gage’s story is typically offered as a paradigm example supporting the view that part of what matters for personal identity is a certain magnitude of similarity between earlier and later individuals. Yet, reconsidering a slight variant of Phineas Gage’s story indicates that it is not just magnitude of similarity, but also the direction of change that affects personal identity judgments; in some cases, changes for the worse are more seen as identity-severing than changes for the better of comparable magnitude. Ironically, thinking carefully about Phineas Gage’s story tells against the thesis it is typically taken to support.

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

The Twin Earth thought experiment invites us to consider a liquid that has all of the superficial properties associated with water (clear, potable, etc.) but has entirely different deeper causal properties (composed of “XYZ” rather than of H2O). Although this thought experiment was originally introduced to illuminate questions in the theory of reference, it has also played a crucial role in empirically informed debates within the philosophy of psychology about people’s ordinary natural kind concepts. Those debates have sought to accommodate an apparent fact about ordinary people’s judgments: Intuitively, the Twin Earth liquid is not water. We present results from four experiments showing that people do not, in fact, have this intuition. Instead, people tend to have the intuition that there is a sense in which the liquid is not water but also a sense in which it is water. We explore the implications of this finding for debates about theories of natural kind concepts, arguing that it supports views positing two distinct criteria for membership in natural kind categories – one based on deeper causal properties, the other based on superficial, observable properties.

Two separate research programs have revealed two different factors that feature in our judgments of whether some entity persists. One program—inspired by Knobe—has found that normative considerations affect persistence judgments. For instance, people are more inclined to view a thing as persisting when the changes it undergoes lead to improvements. The other program—inspired by Kelemen—has found that teleological considerations affect persistence judgments. For instance, people are more inclined to view a thing as persisting when it preserves its purpose. Our goal in this paper is to determine what causes persistence judgments. Across four studies, we pit normative considerations against teleological considerations. And using causal modeling procedures, we find a consistent, robust pattern with teleological and not normative considerations directly causing persistence judgments. Our findings put teleology in the driver’s seat, while at the same time shedding further light on our folk notion of an object.

The personal identity relation is of great interest to philosophers, who often consider fictional scenarios to test what features seem to make persons persist through time. But often real examples of neuroscientific interest also provide important tests of personal identity. One such example is the case of Phineas Gage – or at least the story often told about Phineas Gage. Many cite Gage’s story as example of severed personal identity; Phineas underwent such a tremendous change that Gage “survived as a different man.” I discuss a recent empirical finding about judgments about this hypothetical. It is not just the magnitude of the change that affects identity judgment; it is also the negative direction of the change. I present an experiment suggesting that direction of change also affects neuroethical judgments. I conclude we should consider carefully the way in which improvements and deteriorations affect attributions of personal identity. This is particularly important since a number of the most crucial neuroethical decisions involve varieties of cognitive enhancements or deteriorations.

A classic debate concerns whether reasonableness should be understood statistically (e.g., reasonableness is what is common) or prescriptively (e.g., reasonableness is what is good). This Article elaborates and defends a third possibility. Reasonableness is a partly statistical and partly prescriptive “hybrid,” reflecting both statistical and prescriptive considerations. Experiments reveal that people apply reasonableness as a hybrid concept, and the Article argues that a hybrid account offers the best general theory of reasonableness. First, the Article investigates how ordinary people judge what is reasonable. Reasonableness sits at the core of countless legal standards, yet little work has investigated how ordinary people (i.e., potential jurors) actually make reasonableness judgments. Experiments reveal that judgments of reasonableness are systematically intermediate between judgments of the relevant average and ideal across numerous legal domains. For example, participants’ mean judgment of the legally reasonable number of weeks’ delay before a criminal trial (ten weeks) falls between the judged average (seventeen weeks) and ideal (seven weeks). So too for the reasonable num- ber of days to accept a contract offer, the reasonable rate of attorneys’ fees, the reasonable loan interest rate, and the reasonable annual number of loud events on a football field in a residential neighborhood. Judgment of reasonableness is better predicted by both statistical and prescriptive factors than by either factor alone. This Article uses this experimental discovery to develop a normative view of reasonableness. It elaborates an account of reasonableness as a hybrid standard, arguing that this view offers the best general theory of reasonableness, one that applies correctly across multiple legal domains. Moreover, this hybrid feature is the historical essence of legal reasonableness: the original use of the “reasonable person” and the “man on the Clapham omnibus” aimed to reflect both statistical and prescriptive considerations. Empirically, reasonableness is a hybrid judgment. And normatively, reasonableness should be applied as a hybrid standard.

One popular conception of natural theology holds that certain purely rational arguments are insulated from empirical inquiry and independently establish conclusions that provide evidence, justification, or proof of God’s existence. Yet, some raise suspicions that philosophers and theologians’ personal religious beliefs inappropriately affect these kinds of arguments. I present an experimental test of whether philosophers and theologians’ argument analysis is influenced by religious commitments. The empirical findings suggest religious belief affects philosophical analysis and offer a challenge to theists and atheists, alike: reevaluate the scope of natural theology’s conclusions or acknowledge and begin to address the influence of religious belief.

Scalar Utilitarianism eschews foundational notions of rightness and wrongness in favor of evaluative comparisons of outcomes. I defend Scalar Utilitarianism from two critiques, the first against an argument for the thesis that Utilitarianism's commitments are fundamentally evaluative, and the second that Scalar Utilitarianism does not issue demands or sufficiently guide action. These defenses suggest a variety of more plausible Scalar Utilitarian interpretations, and I argue for a version that best represents a moral theory founded on evaluative notions, and offers better answers to demandingness concerns than does the ordinary Scalar Utilitarian response. If Utilitarians seek reasonable development and explanation of their basic commitments, they may wish to reconsider Scalar Utilitarianism.

Most plausible moral theories must address problems of partial acceptance or partial compliance. The aim of this paper is to examine some proposed ways of dealing with partial acceptance problems as well as to introduce a new Rule Utilitarian suggestion. Here I survey three forms of Rule Utilitarianism, each of which represents a distinct approach to solving partial acceptance issues. I examine Fixed Rate, Variable Rate, and Optimum Rate Rule Utilitarianism, and argue that a new approach, Maximizing Expectation Rate Rule Utilitarianism, better solves partial acceptance problems

Rule-Consequentialism faces “the problem of partial acceptance”: How should the ideal code be selected given the possibility that its rules may not be universally accepted? A new contender, “Calculated Rates” Rule-Consequentialism claims to solve this problem. However, I argue that Calculated Rates merely relocates the partial acceptance question. Nevertheless, there is a significant lesson from this failure of Calculated Rates. Rule-Consequentialism’s problem of partial acceptance is more helpfully understood as an instance of the broader problem of selecting the ideal code given various assumptions—assumptions about who will accept and comply with the rules, but also about how the rules will be taught and enforced, and how similar the future will be. Previous rich discussions about partial acceptance provide a taxonomy and groundwork for formulating the best version of Rule-Consequentialism.

“Experimental jurisprudence” draws on empirical data to inform questions typically associated with jurisprudence or legal theory. Scholars in this flourishing movement conduct empirical studies about a variety of legal language and concepts. Despite the movement’s growth, its justification is still opaque. Jurisprudence is the study of deep and longstanding theoretical questions about law’s nature, but “experimental jurisprudence,” it might seem, simply surveys laypeople. This Article elaborates and defends experimental jurisprudence. Experimental jurisprudence, appropriately understood, is not only consistent with traditional jurisprudence; it is an essential branch of it.

Recently psychologists and experimental philosophers have reported findings showing that in some cases ordinary people's moral intuitions are affected by factors of dubious relevance to the truth of the content of the intuition. Some defend the use of intuition as evidence in ethics by arguing that philosophers are the experts in this area, and philosophers' moral intuitions are both different from those of ordinary people and more reliable. We conducted two experiments indicating that philosophers and non-philosophers do indeed sometimes have different moral intuitions, but challenging the notion that philosophers have better or more reliable intuitions.

Statistical evidence is crucial throughout disparate impact’s three-stage analysis: during (1) the plaintiff’s prima facie demonstration of a policy’s disparate impact; (2) the defendant’s job-related business necessity defense of the discriminatory policy; and (3) the plaintiff’s demonstration of an alternative policy without the same discriminatory impact. The circuit courts are split on a vital question about the “practical significance” of statistics at Stage 1: Are “small” impacts legally insignificant? For example, is an employment policy that causes a one percent disparate impact an appropriate policy for redress through disparate impact litigation? This circuit split calls for a comprehensive analysis of practical significance testing across disparate impact’s stages. Importantly, courts and commentators use “practical significance” ambiguously between two aspects of practical significance: the magnitude of an effect and confidence in statistical evidence. For example, at Stage 1 courts might ask whether statistical evidence supports a disparate impact (a confidence inquiry) and whether such an impact is large enough to be legally relevant (a magnitude inquiry). Disparate impact’s texts, purposes, and controlling interpretations are consistent with confidence inquires at all three stages, but not magnitude inquiries. Specifically, magnitude inquiries are inappropriate at Stages 1 and 3—there is no discriminatory impact or reduction too small or subtle for the purposes of the disparate impact analysis. Magnitude inquiries are appropriate at Stage 2, when an employer defends a discriminatory policy on the basis of its job-related business necessity.

Many philosophers claim to employ intuitions in their philosophical arguments. Others contest that no such intuitions are used frequently or at all in philosophy. This article suggests and defends a conception of intuitions as part of the philosophical method: intuitions are special types of philosophical assumptions to which we are invited to assent, often as premises in argument, that may serve an independent function in philosophical argument and that are not formed through a purely inferential process. A series of philosophical case studies shows that intuitions in these arguments contain the relevant features. The view has implications for philosophical method, offering a compromise between opponents on the divisive debate of the merits of experimental philosophy: experimental philosophy provides an especially useful role in philosophical assumption analysis

Despite pervasive variation in the content of laws, legal theorists and anthropologists have argued that laws share certain abstract features and even speculated that law may be a human universal. In the present report, we evaluate this thesis through an experiment administered in 11 different countries. Are there cross‐cultural principles of law? In a between‐subjects design, participants (N = 3,054) were asked whether there could be laws that violate certain procedural principles (e.g., laws applied retrospectively or unintelligible laws), and also whether there are any such laws. Confirming our preregistered prediction, people reported that such laws cannot exist, but also (paradoxically) that there are such laws. These results document cross‐culturally and –linguistically robust beliefs about the concept of law which defy people's grasp of how legal systems function in practice.

What constitutes a “good” life—not necessarily a morally good life, but a life that is good for the person who lived it? In response to this question of “well-being," philosophers have offered three significant answers: A good life is one in which a person can satisfy their desires (“Desire-Satisfaction” or “Preferentism”), one that includes certain good features (“Objectivism”), or one in which pleasurable states dominate or outweigh painful ones (“Hedonism”). To adjudicate among these competing theories, moral philosophers traditionally gather data from thought experiments and intuition. In this chapter, we supplement that traditional approach with a pair of experimental studies that examine whether the three theories reflect laypeople’s intuitions about well-being. The empirical studies yield two primary findings. First, they provide evidence for lay "well-being pluralism": laypeople treat desire satisfaction, positive objective conditions, and happiness as all constitutive of well-being. Second, the studies provide evidence of "hedonic dominance": laypeople evaluate an individual’s happiness as more important to an individual’s overall well-being than desire satisfaction or objective conditions.

Responding to recent concerns about the reliability of the published literature in psychology and other disciplines, we formed the X-Phi Replicability Project to estimate the reproducibility of experimental philosophy. Drawing on a representative sample of 40 x-phi studies published between 2003 and 2015, we enlisted 20 research teams across 8 countries to conduct a high-quality replication of each study in order to compare the results to the original published findings. We found that x-phi studies – as represented in our sample – successfully replicated about 70% of the time. We discuss possible reasons for this relatively high replication rate in the field of experimental philosophy and offer suggestions for best research practices going forward.

Legal theorists seek to persuade other jurists of certain theories: Textualism or purposivism; formalism or realism; natural law theory or positivism; prison reform or abolition; universal or particular human rights? Despite voluminous literature about these debates, tremendous uncertainty remains about which views experts endorse. This Article presents the first-ever empirical study of American law professors about legal theory questions. A novel dataset of over six hundred law professors reveals expert consensus and dissensus about dozens of longstanding legal theory debates. Law professors also debate questions about the nature of the legal academy. Descriptively, which subjects (e.g. constitutional law) and methods (e.g. law & economics) are most central within the legal academy today? And prescriptively, should today’s legal academy prioritize additional areas (e.g. legislation) or methods (e.g. critical race theory)? There is great interest in these questions but no empirical dataset of experts’ views; this results in uncertainty about which views experts endorse. This Article’s empirical study also clarifies these questions, documenting law professors’ evaluation of over one-hundred areas of law. The legal theory and legal academy findings support implications for legal scholarship, education, and practice. Clearly, debates about law and the legal academy’s evolution should not be settled by a survey. Nevertheless, insofar as law professors are experts about these issues, it is instructive to discover and carefully examine what views those experts hold, so as to help determine which views are most likely to be true and how the legal academy ought to develop.

Jurisprudence aims to identify and explain important features of law. To accomplish this task, what procedure or method should one employ? Elucidating Law, a tour de force in “the philosophy of legal philosophy,” develops an instructive account of how philosophers “elucidate law,” which elucidates jurisprudence’s own aims and methods. This Review introduces the book, with emphasis on its discussion of methodology. Next, the Review proposes complementing methodological clarification with methodological innovation. Jurisprudence should ask timeless questions, but its methods need not stagnate. Consider that jurisprudence has a long tradition of asserting claims about how “we” understand the law---where “we” might refer to all people, ordinary people, legal experts, or legal officials. There are now rich empirical literatures that bear on these claims, and methods from “experimental jurisprudence” and related disciplines can assess untested assertions. Today’s jurisprudence can achieve greater rigor by complementing traditional methods with empirical ones.

The Twin Earth thought experiment invites us to consider a liquid that has all of the superficial properties associated with water (clear, potable, etc.) but has entirely different deeper causal properties (composed of “XYZ” rather than of H2O). Debates about natural kind concepts have sought to accommodate an apparent fact about ordinary people's judgments: Intuitively, the Twin Earth liquid is not water. We present results showing that people do not have this intuition. Instead, people tend to judge that there is a sense in which the liquid is not water but also a sense in which it is water.

Wonder’s significance is a recurrent theme in the history of philosophy. In the Theaetetus, Plato’s Socrates claims that philosophy begins in wonder (thaumazein). Aristotle echoes these sentiments in his Metaphysics; it is wonder and astonishment that first led us to philosophize. Philosophers from the Ancients through Wittgenstein discuss wonder, yet scant recent attention has been given to developing a general systematic account of emotional wonder. I develop an account of emotional wonder and defend its connection with apparent or seeming value. Recently, several philosophers invoke wonder to back non-eudaimonistic value judgments. I introduce methods to incorporate these judgments into a eudaimonistic moral framework. On the analysis presented, wonder requires its object to seem valuable, but whether the object is in fact valuable remains an open question. Wonder enraptures us with objects that might be of true or merely illusory value, grounded either in our own well-being or in non-eudaimonistic value.

Recent experimental studies in cognitive science report the influence of “disgust” and “cleanliness” manipulations on moral judgment, yet little attention has been given to interpreting these studies together or developing models of the causal influence of cleanliness and disgust manipulations on moral judgment. I propose considerations for the causal modeling of these effects. The conclusions are not decisive in favor of one theory of disgust and cleanliness, but suggest several distinct causal roles of disgust- and cleanliness-type manipulations. The incorrect views, I argue, are those that posit causal effects from a single common cognitive mechanism for both disgust and cleanliness

Recent psychology research has established that people do not employ a simple unidimensional scale for attributions of personhood, increasing from non-sentient rocks to mentally complex humans. Rather, there are two personhood dimensions: agency (e.g. planning, deciding, acting) and experience (e.g. feeling, desiring, experiencing). Here we show that this subtle distinction also occurs in the semantic space of natural language. We develop computational-linguistics tools for measuring variation in agency and experience in language and validate the measures against human judgments. To demonstrate the usefulness of the method, we map both dimensions of personhood in historical English-language corpora over the last 200 years. First, we show that while women are now perceived as having similar levels of agency as men, they are still perceived as more patient-like. Second, we show that domesticated animals have gradually gained higher attributions of experience, but not agency, over time.

Perhaps the most fundamental principle of legal interpretation is the presumption that terms should be given their “ordinary” (i.e., general, non-technical) meanings. This principle is a central tenet of modern textualism. Textualists believe a universal presumption of ordinary meaning follows from their theory’s core commitment: A law should be interpreted consistently with what its text communicates to the ordinary public. This Article begins from this textualist premise, empirically examining what legal texts communicate to the public. Five original empirical studies (N = 4,365) reveal a surprising finding: Ordinary people consider genre carefully and regularly take terms in law to communicate technical legal meanings, not ordinary ones. This discovery carries implications for legal interpretation’s theory and practice. Modern textualists—especially at the Supreme Court—justify their theory through “democratic,” fair notice, and rule-of-law appeals to ordinary people. But the empirical studies reveal that fidelity to ordinary people does not imply an unwavering commitment to ordinary meaning. Instead, it requires interpreters to also look to technical meanings. On a practical level, the results support a new presumption of legal meaning and ground a new challenge to textualism’s claim to promote fair notice. As a case study, we consider Bostock v. Clayton County, Georgia, which held that both sexual orientation and gender identity discrimination are prohibited forms of sex discrimination. The Article’s empirics and theory offer a new justification of the Court’s landmark decision.