The National Center for Biomedical Ontology is now in its seventh year. The goals of this National Center for Biomedical Computing are to: create and maintain a repository of biomedical ontologies and terminologies; build tools and web services to enable the use of ontologies and terminologies in clinical and translational research; educate their trainees and the scientific community broadly about biomedical ontology and ontology-based technology and best practices; and collaborate with a variety of groups who develop and use ontologies and (...) terminologies in biomedicine. The centerpiece of the National Center for Biomedical Ontology is a web-based resource known as BioPortal. BioPortal makes available for research in computationally useful forms more than 270 of the world's biomedical ontologies and terminologies, and supports a wide range of web services that enable investigators to use the ontologies to annotate and retrieve data, to generate value sets and special-purpose lexicons, and to perform advanced analytics on a wide range of biomedical data. (shrink)

The meeting focused on uses of ontologies, with a special focus on spatial ontologies, in addressing the ever increasing needs faced by biology and medicine to cope with ever expanding quantities of data. To provide effective solutions computers need to integrate data deriving from myriad heterogeneous sources by bringing the data together within a single framework. The meeting brought together leaders in the field of what are called "top-level ontologies" to address this issue, and to establish strategies among leaders in (...) the field of biomedical ontology for the creation of interoperable biomedical ontologies which will serve the goal of useful data integration. (shrink)

In a world that is overflowing with journals and other outlets for scientific publication, the appearance of any new periodical requires some justification. There are already more journals than we can read and more conferences than we can attend. In the case of applied Ontology, we believe that the creation of anew journal not only is completely justifiable, it is downright exciting. For too long, workers in computer science have assumed that content comes for free. “Theory” in computer science has (...) always meant the theory of processes and of computation. We measure the complexity of computer programs in terms of how long it takes machines to execute them, not in terms of how long it takes people to understand and to represent the data on which those programs might operate. We typically describe computer code in terms of algorithms that operate on formal parameters, often without pausing to discuss where the data that might satisfy those parameters come from. This journal was founded on the premise that workers in computer science, informatics, and information science are overdue in paying as much attention to contents as they do to algorithms. (shrink)

Semantic interoperability requires the use of standards, not only for Electronic Health Record (EHR) data to be transferred and structurally mapped into a receiving repository, but also for the clinical content of the EHR to be interpreted in conformity with the original meanings intended by its authors. Accurate and complete clinical documentation, faithful to the patient’s situation, and interoperability between systems, require widespread and dependable access to published and maintained collections of coherent and quality-assured semantic resources, including models such as (...) archetypes and templates that would (1) provide clinical context, (2) be mapped to interoperability standards for EHR data, (3) be linked to well specified, multi-lingual terminology value sets, and (4) be derived from high quality ontologies. Wide-scale engagement with professional bodies, globally, is needed to develop these clinical information standards. (shrink)

This is a short editorial to introduce the double issue of Applied Ontology that celebrates the journal's tenth anniversary. At a time when information technology of all kinds depends on the use of explicit ontologies, our journal addresses the modeling issues that underlie the next generation of computational systems. As the editors of Applied Ontology, we are excited by how far we have come in the past decade and by the opportunities that await our research community.

Each annual Ontology Summit initiative makes a statement appropriate to each Summit’s theme as part of our general advocacy designed to bring ontology science and engineering into the mainstream. The theme this year is "Towards an Open Ontology Repository". This communiqué represents the joint position of those who were engaged in the year's summit discourse on an Open Ontology Repository (OOR) and of those who endorse below. In this discussion, we have agreed that an "ontology repository is a facility where (...) ontologies and related information artifacts can be stored, retrieved and managed." -/- We believe in the promise of semantic technologies based on logic, databases and the Semantic Web, a Web of exposed data and of interpretations of that data (i.e., of semantics), using common standards. Such technologies enable distinguishable, computable, reusable, and sharable meaning of Web and other artifacts, including data, documents, and services. We also believe that making that vision a reality requires additional supporting resources and these resources should be open, extensible, and provide common services over the ontologies. (shrink)

The National Center for Biomedical Ontology is a consortium that comprises leading informaticians, biologists, clinicians, and ontologists, funded by the National Institutes of Health (NIH) Roadmap, to develop innovative technology and methods that allow scientists to record, manage, and disseminate biomedical information and knowledge in machine-processable form. The goals of the Center are (1) to help unify the divergent and isolated efforts in ontology development by promoting high quality open-source, standards-based tools to create, manage, and use ontologies, (2) to create (...) new software tools so that scientists can use ontologies to annotate and analyze biomedical data, (3) to provide a national resource for the ongoing evaluation, integration, and evolution of biomedical ontologies and associated tools and theories in the context of driving biomedical projects (DBPs), and (4) to disseminate the tools and resources of the Center and to identify, evaluate, and communicate best practices of ontology development to the biomedical community. Through the research activities within the Center, collaborations with the DBPs, and interactions with the biomedical community, our goal is to help scientists to work more effectively in the e-science paradigm, enhancing experiment design, experiment execution, data analysis, information synthesis, hypothesis generation and testing, and understand human disease. (shrink)

BioPortal is a Web portal that provides access to a library of biomedical ontologies and terminologies developed in OWL, RDF(S), OBO format, Protégé frames, and Rich Release Format. BioPortal functionality, driven by a service-oriented architecture, includes the ability to browse, search and visualize ontologies (Figure 1). The Web interface also facilitates community-based participation in the evaluation and evolution of ontology content.

Report on Dagstuhl Seminar 07132, Schloss Dagstuhl, March 27-30 , 2007.

Research notes of Mark Pettinelli about cognitive science, cognitive psychology.

This article is one of the final works of Mark Pettinelli and discusses feelings, emotions and cognitive psychology.

The best writing of Mark Pettinelli, about cognitive psychology, cognitive science, etc.

Provides an overview of Mark Sharlow's philosophical work with summaries of his positions. Includes references and links to his writings.

Augustine and William James both argue that religious faith can be both practical and rational even in the absence of knowledge. Augustine argues that religious faith is trust and that trust is a normal, proper, and even necessary way of believing. Beginning with faith, we then work towards knowledge by means of philosophical contemplation. James’ “The Will to Believe” makes pragmatic arguments for the rationality of faith. Although we do not know (yet) whether God exists, faith is a choice between (...) the risk of believing something false and the risk of not believing something true, and in the absence of convincing evidence we may decide for ourselves which risk we prefer. We may be able to experience God in the future and thereby gain knowledge, yet this may be contingent on our willingness to believe. There are key differences, however. Augustine is a Christian with a neo-Platonic bent, James an empiricist defending the religion of your choice. These differences may be less significant than they first appear. After explaining Augustine and then James I draw out the major points of comparison and contrast and suggest a few reasons their insights might be at least partially synthesized. -/- This is the accepted version of the following article: Mark J. Boone, “Augustine and William James on the Rationality of Faith,” The Heythrop Journal (online edition December 2018), which has been published in final form at [See First URL]. This article may be used for non-commercial purposes in accordance with the Wiley Self-Archiving Policy [See Second URL]. (shrink)

Beliefs are concrete particulars containing ideas of properties and notions of things, which also are concrete. The claim made in a belief report is that the agent has a belief (i) whose content is a specific singular proposition, and (ii) which involves certain of the agent's notions and ideas in a certain way. No words in the report stand for the notions and ideas, so they are unarticulated constituents of the report's content (like the relevant place in "it's raining"). The (...) belief puzzles (Hesperus, Cicero, Pierre) involve reports about two different notions. So the analysis gets the puzzling truth values right. (shrink)

YouTube has been implicated in the transformation of users into extremists and conspiracy theorists. The alleged mechanism for this radicalizing process is YouTube’s recommender system, which is optimized to amplify and promote clips that users are likely to watch through to the end. YouTube optimizes for watch-through for economic reasons: people who watch a video through to the end are likely to then watch the next recommended video as well, which means that more advertisements can be served to them. This (...) is a seemingly innocuous design choice, but it has a troubling side-effect. Critics of YouTube have alleged that the recommender system tends to recommend extremist content and conspiracy theories, as such videos are especially likely to capture and keep users’ attention. To date, the problem of radicalization via the YouTube recommender system has been a matter of speculation. The current study represents the first systematic, pre-registered attempt to establish whether and to what extent the recommender system tends to promote such content. We begin by contextualizing our study in the framework of technological seduction. Next, we explain our methodology. After that, we present our results, which are consistent with the radicalization hypothesis. Finally, we discuss our findings, as well as directions for future research and recommendations for users, industry, and policy-makers. (shrink)

It is an honor to receive such careful and attentive criticism. In this response, I attempt to put the criticisms of the reasons latesters into the context of my argumentative aims in the book and to point toward how they might be answered.

In Naked, Krista K. Thomason offers a multi-faceted account of shame, covering its nature as an emotion, its positive and negative roles in moral life, its association with violence, and its provocation through invitations to shame, public shaming, and stigmatization. Along the way, she reflects on a range of examples drawn from literature, memoirs, journalism, and her own imagination. She also considers alternative views at length, draws a wealth of important distinctions, and articulates many of the most intuitive objections to (...) her own view in order to defend it more thoroughly. As such, the book’s subtitle, The Dark Side of Shame and Moral Life, undersells its scope and ambition. This is an exploration not just of shame’s dark side but a kaleidoscopic appreciation of both the nature and the (dis)value of shame and shaming. Somewhat undercutting this breadth, Thomason relies heavily on Kantian intuitions about equal respect and recognition for persons and their dignity; in several key arguments, she tells us to disregard predictable and systematic consequences of emotions, practices, and institutions so that we can better focus on their constitutive or internal aspects. Of course, every philosopher inevitably brings theoretical commitments to bear when writing about moral psychology, but non-Kantian readers should be forewarned that — despite the fact that Thomason says that she does “not assume any particular moral theory” — her ethical conclusions about shaming and stigmatizing are likely to be plausible only to those who are already snugly tied into a web of “Kantian commitments” (p. 9). (shrink)

This collection of articles is almost all of the psychological writings of Mark Pettinelli.

An archive of Mark Sharlow's two blogs, "The Unfinishable Scroll" and "Religion: the Next Version." Covers Sharlow's views on metaphysics, epistemology, mind, science, religion, and politics. Includes topics and ideas not found in his papers.

Cathy Mason (2020) argues – against my position in Phelan (2019) – that significant norm-manipulation is unnecessary for friendship. Instead, she holds that norm manipulation is a, perhaps omnipresent, causal result of the very feature I deny as necessary to friendship: mutual caring or love. Mason’s counter-examples allow for further explication of the norm-manipulation view of friendship. However, they do not constitute a compelling challenge to that view, because they do not seem to involve collaborative norm manipulation at all. Instead, (...) they are better described as cases in which people come to be subject to established cultural norms they were not previously subject to, because they voluntarily come to fall under a distinctive relationship relative to one another. (shrink)

NOW OPEN-ACCESS! In Reason, Authority, and the Healing of Desire in the Writings of Augustine, Mark Boone explains Augustine’s theology of desire in a cross-section of his writings. He shows that Augustine's writings consistently teach a Platonically informed, yet distinctively Christian, theology of desire.

Using path-breaking discoveries of cognitive science, Mark Johnson argues that humans are fundamentally imaginative moral animals, challenging the view that morality is simply a system of universal laws dictated by reason. According to the Western moral tradition, we make ethical decisions by applying universal laws to concrete situations. But Johnson shows how research in cognitive science undermines this view and reveals that imagination has an essential role in ethical deliberation. Expanding his innovative studies of human reason in Metaphors We (...) Live By and The Body in the Mind, Johnson provides the tools for more practical, realistic, and constructive moral reflection. (shrink)

Many scholars agree that the Internet plays a pivotal role in self-radicalization, which can lead to behaviours ranging from lone-wolf terrorism to participation in white nationalist rallies to mundane bigotry and voting for extremist candidates. However, the mechanisms by which the Internet facilitates self-radicalization are disputed; some fault the individuals who end up self-radicalized, while others lay the blame on the technology itself. In this paper, we explore the role played by technological design decisions in online self-radicalization in its myriad (...) guises, encompassing extreme as well as more mundane forms. We begin by characterizing the phenomenon of technological seduction. Next, we distinguish between top-down seduction and bottom-up seduction. We then situate both forms of technological seduction within the theoretical model of dynamical systems theory. We conclude by articulating strategies for combatting online self-radicalization. (shrink)

Scholars have devoted considerable attention to the discovery by Justin D’Arms and Daniel Jacobson of a distinction between the fittingness of an emotion and the propriety of the same. Meanwhile, Christian theology has long been attentive to the relevance of Christian theology to the emotions. Although it seems that never so far have the twain discussions met, they should meet. A fitting emotion accurately construes a situation. Christian theology tells us something about the importance—or the lack thereof—of emotional fit for (...) the emotions involved in love. It is a desideratum for the emotions that they are fitting. But other desiderata for the emotional life sometimes overrule the desideratum of fit. Moreover, emotions sometimes have an effect on their own fittingness. As Kierkegaard shows, love construes its object as better than he presently is, but it also makes the object better. We should cultivate a disposition to loving emotions that are occasionally unfitting yet help to bring about better fit. I explain these things and consider how someone might go about cultivating loving emotions which are sometimes unfitting yet also restorative of fit. (shrink)

This book is a collection of some of my writings that do not fit the mold of standard philosophical articles. These writings range over several topics, including religion, free will, human dignity, the nature of persons, and a few others. The longest item in the collection is an archive of my blog, The Unfinishable Scroll, as it existed when the book was put together. That blog covers many philosophical topics, including some I haven't discussed elsewhere. Also in the collection are (...) essays (formerly web-based) on topics ranging from progress, to skepticism, to metaphysics - and back again. The book even contains an archive of another, less well-known, blog of mine. (shrink)

According to Danièle Moyal-Sharrock, Wittgenstein’s On Certainty presents a theory of hinges, and hinges have a role to play in a foundationalist epistemology (2013). Michael Williams (2005) and Annalisa Coliva (2013 ) have claimed that the hinges are not suitable to play such a role as they are not shared universally. Moyal-Sharrock has replied that a subset of the hinges is suitable to play such a role: the “universal” hinges. I argue that for Moyal-Sharrock’s reply to be sustained, she must (...) construe the set of universal hinges much more narrowly than she does currently. For instance, Moyal-Sharrock claims that “I have a brain” is a universal hinge, which consigns people who know nothing about brains to stand outside the bounds of sense. I also provide a novel way of thinking about the universal hinges, which I argue is better textually motivated than Moyal-Sharrock’s own way, and which provides a set of hinges more suitable to play a role in foundationalist epistemology. (shrink)

(No abstract is available for this citation).

Most philosophers find it puzzling how beliefs could wrong, and this leads them to conclude that they do not. So there is much philosophical work to be done in sorting out whether I am right to say that they do, as well as how this could be so. But in this paper I will take for granted that beliefs can wrong, and ask instead when beliefs wrong. My answer will be that beliefs wrong when they falsely diminish. This answer has (...) three parts: that beliefs wrong only when they are false, that beliefs wrong only when they diminish, and that false diminishment is sufficient for wronging. I will seek to elaborate on and defend all three of these claims, but it is the first to which I will give the most attention. (shrink)

Philosophers have come to distinguish between ‘right’ and ‘wrong’ kinds of reasons for belief, intention, and other attitudes. Several theories about the nature of this distinction have been offered, by far the most prevalent of which is the idea that it is, at bottom, the distinction between what are known as ‘object-given’ and ‘state-given’ reasons. This paper argues that the object-given/state-given theory vastly overgeneralizes on a small set of data points, and in particular that any adequate account of the distinction (...) between the ‘right’ and ‘wrong’ kinds of reason must allow state-given reasons to be of the right kind. The paper has three main goals, corresponding to its three main parts. In part 1 I set up the problem by introducing the right-kind/wrong-kind distinction, the object-given/state-given distinction, and the object-given/state-given theory, according to which the former distinction simply amounts to the latter. Part 2 presents the main argument of the paper: I argue against the object-given/state-given theory by showing that all of the earmarks of the ‘right’ and ‘wrong’ kinds of reason apply to reasons not to intend and not to believe, but that these cases can’t be captured by the object-given/state-given theory. Finally, in part 3 I use these arguments to motivate and explore a more general hypothesis about the rightkind/wrong-kind distinction, and explore some of the consequences of rejecting the object-given/stategiven theory. (shrink)

In “Of Personal Identity”, Hume attempts to understand why we ordinarily believe in persistent selves. He proposes that this ontological commitment depends on illusions and fictions: the imagination tricks us into supposing that an unchanging core self remains static through the flux and change of experience. Recent work in cognitive science provides a good deal of support for Hume’s hypothesis that common beliefs about the self are founded on psychological biases rather than rational insight or evidence. We naturally believe in (...) personal persistence, according to this emerging research, because we are prone to categorize the world in terms of hidden essences and structure our lives in terms of whole life stories. (shrink)

In “On Sense and Reference,” surrounding his discussion of how we describe what people say and think, identity is Frege’s first stop and his last. We will follow Frege’s plan here, but we will stop also in the land of make-believe.

Several authors have recently endorsed the thesis that there is what has been called pragmatic encroachment on knowledge—in other words, that two people who are in the same situation with respect to truth-related factors may differ in whether they know something, due to a difference in their practical circumstances. This paper aims not to defend this thesis, but to explore how it could be true. What I aim to do, is to show how practical factors could play a role in (...) defeating knowledge by defeating epistemic rationality—the very kind of rationality that is entailed by knowledge, and in which Pascalian considerations do not play any role—even though epistemic rationality consists in having adequate evidence. (shrink)

An account of distinctively mathematical explanation (DME) should satisfy three desiderata: it should account for the modal import of some DMEs; it should distinguish uses of mathematics in explanation that are distinctively mathematical from those that are not (Baron [2016]); and it should also account for the directionality of DMEs (Craver and Povich [2017]). Baron’s (forthcoming) deductive-mathematical account, because it is modelled on the deductive-nomological account, is unlikely to satisfy these desiderata. I provide a counterfactual account of DME, the Narrow (...) Ontic Counterfactual Account (NOCA), that can satisfy all three desiderata. NOCA appeals to ontic considerations to account for explanatory asymmetry and ground the relevant counterfactuals. NOCA provides a unification of the causal and the non-causal, the ontic and the modal, by identifying a common core that all explanations share and in virtue of which they are explanatory. (shrink)

This chapter explores a case study in contemporary fanaticism. We adopt Katsafanas’s conceptualization of fanaticism to make possible an in-depth discussion of and evaluation of a diffuse but important social movement — the anglophone manosphere. According to Katsafanas, fanatics are fruitfully understood as members of a group that adopts sacred values which they hold unconditionally to preserve their own psychic unity, and who feel that those values are threatened by those who do not accept them. The manosphere includes several social (...) movements, including incels, men’s rights activists, and men-going-their-own-way. We show that many members of these groups are well-characterized by Katsafanas’s theory of fanaticism, and that they have forged their fanatical group identity using tools that philosophers have tended to associate with more benign social movements and the task of “conceptual engineering.” Indeed, we think that manosphere groups have in many cases been more successful than more palatable liberationist movements, and that this case study in the dark side of conceptual engineering may be both sobering and informative. (shrink)

Because obituaries are succinct and explicitly intended to summarize their subjects’ lives, they may be expected to include only the features that the author finds most salient but also to signal to others in the community the socially-recognized aspects of the deceased’s character. We begin by reviewing studies 1 and 2, in which obituaries were carefully read and labeled. We then report study 3, which further develops these results with a semi-automated, large-scale semantic analysis of several thousand obituaries. Geography, gender, (...) and elite status all turn out to be associated with the virtues and values associated with the deceased. (shrink)

This article considers two important problems for the idea that what we ought to do is determined by the balance of competing reasons. The problems are distinct, but the object of the article is to explore how they admit of a single solution. It is a consequence of this solution that objective reasons—facts that count in favor—are in an important sense less objective than they have consistently been assumed to be. This raises but does not answer the question as to (...) what evidence we ever had that reasons are as objective as has been assumed. (shrink)

My concern is to overturn the Leibnizean model of God's creation of the world which proposes that God selected a possible world out of a whole host of other alternative ones. This is the familiar possible worlds model of creation. I argue that this understanding of creation does not take seriously the idea of ex nihilo and that, rather than considering determinate possible worlds, we should understand possibility as indeterminate. I then develop this argument and explores how it impacts on (...) the idea of providence, and the problem of evil. I then explore the notion of creativity. Only a God who can make something utterly novel is a God who is making something different from Himself and which consequently has no divine precedent. A God who uses possible worlds makes nothing new. -/- . (shrink)

Virtues are dispositions that make their bearers admirable. Dispositions can be studied scientifically by systematically varying whether their alleged bearers are in (or take themselves to be in) the dispositions' eliciting conditions. In recent decades, empirically-minded philosophers looked to social and personality psychology to study the extent to which ordinary humans embody dispositions traditionally considered admirable in the Aristotelian tradition. This led some to conclude that virtues are not attainable ideals, and that we should focus our ethical reflection and efforts (...) more on jerry-rigging our environments than on improving our characters. Most virtue ethicists resisted this reorientation. However, much of the scientific evidence on which the controversy was based has failed to replicate, raising the question of how much faith we should place in methodologically suspect studies. In this paper, I assess the state of the debate and recommend best practices for a renewed interdisciplinary investigation of virtues and vices in which philosophical expertise related to conceptualization and theorizing is essentially intertwined with scientific expertise related to operationalization, measurement, and statistics. (shrink)

This paper presents five studies on the development and validation of a scale of intellectual humility. This scale captures cognitive, affective, behavioral, and motivational components of the construct that have been identified by various philosophers in their conceptual analyses of intellectual humility. We find that intellectual humility has four core dimensions: Open-mindedness (versus Arrogance), Intellectual Modesty (versus Vanity), Corrigibility (versus Fragility), and Engagement (versus Boredom). These dimensions display adequate self-informant agreement, and adequate convergent, divergent, and discriminant validity. In particular, Open-mindedness (...) adds predictive power beyond the Big Six for an objective behavioral measure of intellectual humility, and Intellectual Modesty is uniquely related to Narcissism. We find that a similar factor structure emerges in Germanophone participants, giving initial evidence for the model’s cross-cultural generalizability. (shrink)

The Enarrationes in Psalmos is the collection of Augustine’s commentaries and sermons on the Psalms. Although Augustine is often at his philosophical best here, bearing various resemblances to the Platonists and other philosophers, he also articulates a distinctively Christian view on what we should desire, on how desire has gone wrong, and on how it is healed. The renewal of desire takes place as a result of and through the unity of Christ and the church, which is the guiding theme (...) of the Enarrationes. Augustine’s Preaching and the Healing of Desire in the Enarrationes in Psalmos traces this theology of desire as it connects to Augustine’s Christology, his ecclesiology, his account of happiness and well-being, and his eschatology. The book closes with some suggestions on what the church can learn today from the Enarrationes in the areas of psychology and wellbeing, biblical exegesis, and homiletics. (shrink)

I develop and defend a truthmaker semantics for the relevant logic R. The approach begins with a simple philosophical idea and develops it in various directions, so as to build a technically adequate relevant semantics. The central philosophical idea is that truths are true in virtue of specific states. Developing the idea formally results in a semantics on which truthmakers are relevant to what they make true. A very natural notion of conditionality is added, giving us relevant implication. I then (...) investigate ways to add conjunction, disjunction, and negation; and I discuss how to justify contraposition and excluded middle within a truthmaker semantics. (shrink)

The inflation of Type I error rates is thought to be one of the causes of the replication crisis. Questionable research practices such as p-hacking are thought to inflate Type I error rates above their nominal level, leading to unexpectedly high levels of false positives in the literature and, consequently, unexpectedly low replication rates. In this article, I offer an alternative view. I argue that questionable and other research practices do not usually inflate relevant Type I error rates. I begin (...) by introducing the concept of Type I error rates and distinguishing between statistical errors and theoretical errors. I then illustrate my argument with respect to model misspecification, multiple testing, selective inference, forking paths, exploratory analyses, p-hacking, optional stopping, double dipping, and HARKing. In each case, I demonstrate that relevant Type I error rates are not usually inflated above their nominal level, and in the rare cases that they are, the inflation is easily identified and resolved. I conclude that the replication crisis may be explained, at least in part, by researchers’ misinterpretation of statistical errors and their underestimation of theoretical errors. (shrink)

The consequences of Quine's criterion of ontological commitment epitomized in his treatment of the term 'Pegasus' in "On What There Is" are evaluated in terms of Quine's own work, in particular in "The Variable" and "Variables Explained Away". There is a cost to maintaining this criterion with regard to the empirical consequences of some non-existent objects, given considerations prompted by Quine's holism. This cost can be reduced by adopting a noneist position according to which non-existent objects can be values of (...) bound variables as well. (shrink)

Mark Eli Kalderon presents an original study of perception, taking as its starting point a puzzle in Empedocles' theory of vision: if perception is a mode of material assimilation, how can we perceive colors at a distance? Kalderon argues that the theory of perception offered by Aristotle in answer to the puzzle is both attractive and defensible.