Individuality is an important concept in biology, yet there are many non-equivalent criteria of individuality expressed in different kinds of biological individuals. This article evaluates these different kinds in terms of their capacity to support explanatory generalizations over the systems they individuate. Viewing the problem of individuality from this perspective promotes a splitting strategy in which different kinds make different epistemic trade-offs that suit them for different explanatory roles. I argue that evolutionary individuals, interpreted as forming a functional kind, face (...) difficulties of individuation and explanatory power that are mitigated by relying on more structurally based properties and non-evolutionary kinds. 1Introduction2Kinds of Biological Individuals3Evolutionary Individuals and Functional Kinds4Evolutionary versus Non-evolutionary Kinds of Individuals 4.1Physiological individuality4.2Ecological individuality4.3Developmental individuality5Conclusion. (shrink)

There have been repeated attempts in the history of comparative biology to provide a mechanistic account of morphological homology. However, it is well-established that homologues can develop from diverse sets of developmental causes, appearing not to share any core causal architecture that underwrites character identity. We address this challenge with a new conceptual model of Character Identity Mechanisms. ChIMs are cohesive mechanisms with a recognizable causal profile that allows them to be traced through evolution as homologues despite having a diverse (...) etiological organization. Our model hypothesizes that anatomical units at different levels of organization—cell types, tissues, and organs—have level-specific ChIMs with different conserved parts, activities, and organization. Relying on a methodology of conceptual engineering, we show how the ChIM concept advances our understanding of the developmental basis of morphological characters, while forging an important link between comparative and mechanistic biology. (shrink)

The concept of levels of organization, despite its widespread scientific currency, has recently been criticized by a number of philosophers of science. This paper diagnoses the main source of problems facing theories of levels. On this basis, the problems with the usual criteria for distinguishing levels are evaluated: compositional relations, organizational types, and spatial scales. Drawing on some work on hierarchies in ecology, I argue in favor of an alternative conception of levels defined by the criterion of rates or time (...) scales of processes. (shrink)

The logic of genetic discovery has changed little over time, but the focus of biology is shifting from simple genotype–phenotype relationships to complex metabolic, physiological, developmental, and behavioral traits. In light of this, the traditional reductionist view of individual genes as privileged difference‐making causes of phenotypes is re‐examined. The scope and nature of genetic effects in complex regulatory systems, in which dynamics are driven by regulatory feedback and hierarchical interactions across levels of organization are considered. This review argues that it (...) is appropriate to treat genes as specific actual difference‐makers for the molecular regulation of gene expression. However, they are often neither stable, proportional, nor specific as causes of the overall dynamic behavior of regulatory networks. Dynamical models, properly formulated and validated, provide the tools to probe cause‐and‐effect relationships in complex biological systems, allowing to go beyond the limitations of genetic reductionism to gain an integrative understanding of the causal processes underlying complex phenotypes. (shrink)

Explanation in terms of gene regulatory networks has become standard practice in evolutionary developmental biology. In this paper, we argue that GRNs fail to provide a robust, mechanistic, and dynamic understanding of the developmental processes underlying the genotype–phenotype map. Explanations based on GRNs are limited by three main problems: the problem of genetic determinism, the problem of correspondence between network structure and function, and the problem of diachronicity, as in the unfolding of causal interactions over time. Overcoming these problems requires (...) dynamic mechanistic explanations, which rely not only on mechanistic decomposition, but also on dynamic modeling to reconstitute the causal chain of events underlying the process of development. We illustrate the power and potential of this type of explanation with a number of biological case studies that integrate empirical investigations with mathematical modeling and analysis. We conclude with general considerations on the relation between mechanism and process in evo-devo. (shrink)

Advances in developmental genetics and evo-devo in the last several decades have enabled the growth of novel developmental approaches to the classic theme of homology. These approaches depart from the more standard phylogenetic view by contending that homology between morphological characters depends on developmental-genetic individuation and explanation. This article provides a systematic re-examination of the relationship between developmental and phylogenetic homology in light of current evidence from developmental and evolutionary genetics and genomics. I present a qualitative model of the processes (...) that cause de-coupling of morphological and molecular evolution by developmental system drift (DSD), and hypothesize that DSD is a widespread and regular stochastic process that is predictable from parameters such as population size, pleiotropy, and regulatory redundancy. These theoretical findings support an integrative approach in which models of DSD aid in determining when developmental-genetic explanations of homology apply and when other explanations such as stabilizing selection are needed. I argue that a phylogenetic monism about the definition and criteria of homology supports the integration of different explanations into a theory of homology better than pluralism does. (shrink)

This paper examines three exemplary theories of living organization with respect to their common feature of defining life in terms of metabolic closure: autopoiesis, systems, and chemoton theory. Metabolic closure is broadly understood to denote the property of organized chemical systems that each component necessary for the maintenance of the system is produced from within the system itself, except for an input of energy. It is argued that two of the theories considered—autopoiesis and systems—participate in a hylomorphist pattern of thinking (...) which separates the “form” of the living system from its “matter.” The analysis and critique of hylomorphism found in the work of the philosopher Gilbert Simondon is then applied to these two theories, and on the basis of this critique it is argued that the chemoton model offers a superior theory of minimal life which overcomes many of the problems associated with the other two. Throughout, the relationship between hylomorphism and the understanding of living things as machines is explored. The paper concludes by considering how hylomorphism as a background ontology for theories of life fundamentally influences the way life is defined. (shrink)

The received view of Bergson's philosophy of life is that it advances some form of vitalism under the heading of an “élan vital.” This paper argues against the vitalistic interpretation of Bergson's élan vital as it appears in Creative Evolution in favor of an interpretation based on his overlooked reflections on entropy and energetics. Within the interpretation developed here, the élan vital is characterized not as a spiritualistic “vital force” but as a tendency of organization opposed to the tendency of (...) entropic degradation. It is then shown how Bergson's view of evolution and living organization resonates with more contemporary scientific approaches belonging to a “thermodynamic paradigm” in theoretical biology in different respects, including the critique of neo-Darwinism and the positing of a driving force behind evolution. Finally, the special interest that Bergson's philosophical biology bears today is considered in terms of the connection between the concepts of élan vital and duration. (shrink)

The subject of this edited volume is the idea of levels of organization: roughly, the idea that the natural world is segregated into part-whole relationships of increasing spatiotemporal scale and complexity. The book comprises a collection of essays that raise the idea of levels into its own topic of analysis. Owing to the wide prominence of the idea of levels, the scope of the volume is aimed at theoreticians, philosophers, and practicing researchers of all stripes in the life sciences. The (...) volume’s contributions reflect this diversity, and draw from fields such as developmental biology, evolutionary biology, molecular biology, ecology, cell biology, and neuroscience. The book presents wide-ranging novel insights on causation and levels, the hierarchical structure of evolution, the role of levels in biological theory, and more. (shrink)

Comparative biology builds up systematic knowledge of the diversity of life, across evolutionary lineages and levels of organization, starting with evidence from a sparse sample of model organisms. In developmental biology, a key obstacle to the growth of comparative approaches is that the concept of homology is not very well defined for levels of organization that are intermediate between individual genes and morphological characters. In this paper, we investigate what it means for ontogenetic processes to be homologous, focusing specifically on (...) the examples of insect segmentation and vertebrate somitogenesis. These processes can be homologous without homology of the underlying genes or gene networks, since the latter can diverge over evolutionary time, while the dynamics of the process remain the same. Ontogenetic processes like these therefore constitute a dissociable level and distinctive unit of comparison requiring their own specific criteria of homology. In addition, such processes are typically complex and nonlinear, such that their rigorous description and comparison not only requires observation and experimentation, but also dynamical modeling. We propose six criteria of process homology, combining recognized indicators with novel ones derived from dynamical systems modeling. We show how these criteria apply to animal segmentation and other ontogenetic processes. We conclude by situating our proposed dynamical framework for homology of process in relation to similar research programs, such as process structuralism and developmental approaches to morphological homology. (shrink)

Token physicalism is often viewed as a modest and unproblematic physicalist commitment, as contrasted with type physicalism. This paper argues that the prevalence of functional individuation in biology creates serious problems for token physicalism, because the latter requires that biological entities can be individuated physically and without reference to biological functioning. After characterizing the main philosophical roles for token physicalism, I describe the distinctive uses of functional individuation in models of biological processes. I then introduce some requirements on token identity (...) claims that arise from a position on individuation and identity known as sortalism. An examination of biological examples shows that these sortalist requirements cannot be plausibly met due to differences between individuation by functional biological criteria and by physical criteria. Even without assuming sortalism, token physicalism faces the more basic problem of excluding functionally irrelevant detail from the individuation of biological tokens. I close by suggesting that the philosophical roles for token identity are better fulfilled by a notion of token composition, which promotes a hierarchical picture of individuality. (shrink)

Given the pervasiveness of gene sharing in evolution and the extent of homology across the tree of life, why is everything not homologous with everything else? The continuity and overlapping genetic contributions to diverse traits across lineages seem to imply that no discrete determination of homology is possible. Although some argue that the widespread overlap in parts and processes should be acknowledged as “partial” homology, this threatens a broad base of presumed comparative morphological knowledge accepted by most biologists. Following a (...) long scientific tradition, we advocate a strategy of “theoretical articulation” that introduces further distinctions to existing concepts to produce increased contrastive resolution among the labels used to represent biological phenomena. We pursue this strategy by drawing on successful patterns of reasoning from serial homology at the level of gene sequences to generate an enriched characterization of serial homology as a hierarchical, phylogenetic concept. Specifically, we propose that the concept of serial homology should be applied primarily to repeated but developmentally individualized body parts, such as cell types, differentiated body segments, or epidermal appendages. For these characters, a phylogenetic history can be reconstructed, similar to families of paralogous genes, endowing the notion of serial homology with a hierarchical, phylogenetic interpretation. On this basis, we propose a five-fold theoretical classification that permits a more fine-grained mapping of diverse trait-types. This facilitates answering the question of why everything is not homologous with everything else, as well as how novelty is possible given that any new character possesses evolutionary precursors. We illustrate the fecundity of our account by reference to debates over insect wing serial homologs and vertebrate paired appendages. (shrink)

Adaptationism is often taken to be the thesis that most traits are adaptations. In order to assess this thesis, it seems we must be able to establish either an exhaustive set of all traits or a representative sample of this set. Either task requires a more systematic and principled way of individuating traits than is currently available. Moreover, different trait individuation criteria can make adaptationism turn out true or false. For instance, individuation based on natural selection may render adaptationism true, (...) but may do so by presupposing adaptationism. In this paper, we show how adaptationism depends on trait individuation and that the latter is an open and unsolved problem. (shrink)

A central topic in research at the intersection of development and evolution is the origin of novel traits. Despite progress on understanding how developmental mechanisms underlie patterns of diversity in the history of life, the problem of novelty continues to challenge researchers. Here we argue that research on evolutionary novelty and the closely associated phenomenon of co-option can be reframed fruitfully by: (1) specifying a conceptual model of mechanisms that underwrite character identity, (2) providing a richer and more empirically precise (...) notion of co-option that goes beyond common appeals to “deep homology”, and (3) attending to the nature of experimental interventions that can determine whether and how the co-option of identity mechanisms can help to explain novel character origins. This reframing has the potential to channel future investigation to make substantive progress on the problem of evolutionary novelty. To illustrate this potential, we apply our reframing to two case studies: treehopper helmets and beetle horns. (shrink)

How (Not) to Be Secular is what Jamie Smith calls "your hitchhiker's guide to the present" -- it is both a reading guide to Charles Taylor's monumental work A Secular Age and philosophical guidance on how we might learn to live in our times. Taylor's landmark book A Secular Age (2007) provides a monumental, incisive analysis of what it means to live in the post-Christian present -- a pluralist world of competing beliefs and growing unbelief. Jamie Smith's book is a (...) compact field guide to Taylor's insightful study of the secular, making that very significant but daunting work accessible to a wide array of readers. Even more, though, Smith's How (Not) to Be Secular is a practical philosophical guidebook, a kind of how-to manual on how to live in our secular age. It ultimately offers us an adventure in self-understanding and maps out a way to get our bearings in today's secular culture, no matter who "we" are -- whether believers or skeptics, devout or doubting, self-assured or puzzled and confused. This is a book for any thinking person to chew on. (shrink)

Noted psychologist and philosopher develops his own brand of pragmatism, based on theories of C. S. Peirce. Emphasis on "radical empiricism," versus the transcendental and rationalist tradition. One of the most important books in American philosophy. Note.

Hubert Dreyfus has argued that cases of absorbed bodily coping show that there is no room for self-awareness in flow experiences of experts. In this paper, I argue against Dreyfus’ maxim of vanishing self-awareness by suggesting that awareness of agency is present in expert bodily action. First, I discuss the phenomenon of absorbed bodily coping by discussing flow experiences involved in expert bodily action: merging into the flow; immersion in the flow; emergence out of flow. I argue against the claim (...) that flow experience does not involve an awareness of agency for each of these features, while conceding that fluent agency does not involve self-awareness in the thetic sense. I challenge the assumption that the awareness of fluent agency must be understood in terms of a thetic awareness of agency. Instead, I develop an Anscombean account of the awareness of fluent agency in terms of the phenomenal character of knowing one’s aims. I respond to the challenge that if an Anscombean account of the awareness of agency is to succeed, then agents must be able to answer Anscombean questions. I consider the objection that awareness of agency is not a form of self-awareness by outlining an account of self-awareness as self-synthesis that is distinct from self-perception and self-ascription, but which makes room for self-awareness in expert bodily action. (shrink)

Do Quine and Carnap distort the social nature of inquiry by privileging individual epistemic subjects? This objection is at the heart of Donald Davidson’s claim that Quine fails to grasp the significance of the concept of truth. In Carnap’s case, the objection may be detected in Charles Morris’s call to ground scientific philosophy in semiotics, the science of signs, rather than syntax, the formal investigation of languages. Drawing out the challenge from Morris’s proposal requires examining a neglected influence on this (...) neglected philosopher: his advisor George Herbert Mead’s social theory of mind. I argue that Morris and Davidson can both be understood as demanding that scientific philosophers socialize their conception of objectivity. (shrink)

The Gifford Lectures were established in 1885 at the universities of St Andrews, Glasgow, Aberdeen and Edinburgh to promote the discussion of 'Natural Theology in the widest sense of the term - in other words, the knowledge of God', and some of the world's most influential thinkers have delivered them. The 1901–2 lectures given in Edinburgh by American philosopher William James are considered by many to be the greatest in the series. The lectures were published in book form in (...) 1902 and have been reprinted many times. James, who was educated in the United States and Europe, and spent much of his career teaching philosophy at Harvard, was very influential in the development of modern psychology, and in these twenty lectures he explores the personal experience of religion. Some of the topics include religion and neurology, 'the sick soul', saintliness, and mysticism. (shrink)

In this unique work, James P. Sterba argues that traditional ethics has yet to confront the three significant challenges posed by environmentalism, feminism, and multiculturalism. He maintains that while traditional ethics has been quite successful at dealing with the problems it faces, it has not addressed the possibility that its solutions to these problems are biased in favor of humans, men, and Western culture. In Three Challenges to Ethics: Environmentalism, Feminism, and Multiculturalism, Sterba examines each of these challenges. In (...) the case of environmentalism, he argues that traditional ethics must incorporate conflict resolution principles that favor nonhumans over humans in a significant range of cases. In terms of feminism, he maintains that traditional ethics should rule out gendered family structures and implement an ideal of androgyny. In regard to multiculturalism, he contends that traditional ethics must endorse an ethics that is secular in character and that can survive an extensive comparative evaluation of both Western and non-Western moral ideals and cultures. The only textbook devoted to this topic, Three Challenges to Ethics is an engaging text for introductory courses in ethics and moral problems and is also interesting and provocative reading for scholars and general readers. (shrink)

Rather than representing a break with his earlier philosophical undertakings, The Birth of Tragedy can be seen as continuous with them and Nietzsche's later works. James Porter argues that Nietzsche's argumentative and writerly strategies resemble his earlier writings on philology in his 'staging' of meaning rather than in his advocacy of various positions. The derivation of the Dionysian from the Apollinian, and the interest in the atomistic challenges to Platonism, are anticipated in earlier works. Also the theory of the (...) all-too-human subject is a thread that runs throughout Nietzsche's oeuvre, critically undoing what his philosophy appears to erect, confirming that Nietzsche is a most unreliable witness to his own meaning. As well as studying the relation of The Birth of Tragedy to later writings, the author examines it on its own terms as a self-standing and complete piece of imagining, with close regard to the self-presentation of the work itself. (shrink)

One of the most influential men of his time, philosopher, psychologist, educator, and author William James (1842-1910) helped lead the transition from a predominantly European-centered nineteenth-century philosophy to a new "pragmatic" American philosophy. Helping to pave the way was his seminal book Pragmatism (1907), in which he included a chapter on "Truth," an essay which provoked severe criticism. In response, he wrote the present work, an attempt to bring together all he had ever written on the theory of knowledge, (...) including an article on the function of cognition, later polemic and expository contributions, and some replies to previous criticism. The result was a full and definitive expression of the pragmatist "epistemology" from James' point of view. In the book, he urges the reader to "turn away from abstractions, verbal solutions, fixed principles, and pretended absolutes and look for concreteness and facts, action and power," arguing that "the ultimate test for us of what a truth means is the conduct it dictates or inspires." For students, scholars--anyone interested in William James or the history of American philosophical thought--this book offers an in-depth exposition of the influential ideas of one of the greatest American thinkers. Unabridged republication of the edition originally published by Longmans, Green and Co., New York and London, 1909. (shrink)

Scepticism about ought simpliciter is the view that there is no such thing as what one ought simpliciter to do. Instead, practical deliberation is governed by a plurality of normative standpoints, each authoritative from their own perspective but none authoritative simpliciter. This paper aims to resist such scepticism. After setting out the challenge in general terms, I argue that scepticism can be resisted by rejecting a key assumption in the sceptic’s argument. This is the assumption that standpoint-relative ought judgments bring (...) with them a commitment to act in accordance with those judgments. Instead, I propose an alternative account of our normative concepts according to which only ought simpliciter judgments commit one to acting in accordance with those judgments. In addition to answering the sceptical challenge, the proposal offers an independently motivated account of what makes a concept normatively authoritative. (shrink)

In addition to being one of the world's most influential philosophers, Aristotle can also be credited with the creation of both the science of biology and the philosophy of biology. He was the first thinker to treat the investigations of the living world as a distinct inquiry with its own special concepts and principles. This book focuses on a seminal event in the history of biology - Aristotle's delineation of a special branch of theoretical knowledge devoted to the systematic investigation (...) of animals. Aristotle approached the creation of zoology with the tools of subtle and systematic philosophies of nature and of science that were then carefully tailored to the investigation of animals. The papers collected in this volume, written by a pre-eminent figure in the field of Aristotle's philosophy and biology, examine Aristotle's approach to biological inquiry and explanation, his concepts of matter, form and kind, and his teleology. (shrink)

James I. The Political Works of James I. Reprinted from the Edition of 1616. With an Introduction by Charles Howard McIlwain. Cambridge: Harvard University Press, 1918. cxi, 354 pp. Reprinted 2002 by The Lawbook Exchange, Ltd.

One of the great American pragmatic philosophers alongside Peirce and Dewey, William James (1842–1910) delivered these eight lectures in Boston and New York in the winter of 1906–7. Though he credits Peirce with coining the term 'pragmatism', James highlights in his subtitle that this 'new name' describes a philosophical temperament as old as Socrates. The pragmatic approach, he says, takes a middle way between rationalism's airy principles and empiricism's hard facts. James' pragmatism is both a method of (...) interpreting ideas by their practical consequences and an epistemology which identifies truths according to their useful outcomes. Furnished with many examples, the lectures illustrate pragmatism's response to classic problems such as the question of free will versus determinism. Published in 1907, this work further develops James's approach to religion and morality, introduced in The Will to Believe (1897) and The Varieties of Religious Experience (1902), both reissued in this series. (shrink)

Now in a third edition, Introduction to Philosophy: Classical and Contemporary Readings is a highly acclaimed, topically organized collection that covers five major areas of philosophy--theory of knowledge, philosophy of religion, philosophy of mind, freedom and determinism, and moral philosophy. Editor Louis P. Pojman enhances the text's topical organization by arranging the selections into a pro/con format to help students better understand opposing arguments. He also includes accessible introductions to each chapter, subsection, and individual reading, a unique feature for an (...) anthology of this depth. While the book focuses on a compelling sampling of classical material--including selections from Plato, Aristotle, Descartes, Locke, Berkeley, Hume, and Kant--it also incorporates some of philosophy's best twentieth-century and contemporary work, featuring articles by Bertrand Russell, Richard Taylor, John Searle, Thomas Nagel, and others. This third edition contains an expanded glossary, more extensive section introductions, and twelve new selections: Karl Popper: "Epistemology without a Knowing Subject" Richard Rorty: "Dismantling Truth: Solidarity Versus Objectivity" Daniel Dennett: "Postmodernism and Truth" Bruce Russell: "The Problem of Evil: Too Much Suffering" David Chalmers: "Against Materialism: Can Consciousness Be Reductively Explained?" Baron Paul Henri d'Holbach: "A Defense of Determinism" Michael Levin: "A Compatibilist Defense of Moral Responsibility" Plato: Socratic Morality: "Crito" Herodotus: "Custom Is King" J. L. Mackie: "The Subjectivity of Values" Louis P. Pojman: "A Critique of Mackie's Theory of Moral Subjectivism" Thomas Nagel: "Moral Luck". (shrink)

The Epicurean philosophical system has enjoyed much recent scrutiny, but the question of its philosophical ancestry remains largely neglected. It has often been thought that Epicurus owed only his physical theory of atomism to the fifth-century BC philosopher Democritus, but this study finds that there is much in his ethical thought which can be traced to Democritus. It also finds important influences on Epicurus in Democritus' fourth-century followers such as Anaxarchus and Pyrrho, and in Epicurus' disagreements with his own Democritean (...) teacher Nausiphanes. The result is not only a fascinating reconstruction of a lost tradition, but also an important contribution to the philosophical interpretation of Epicureanism, bearing especially on its ideal of tranquillity and on the relation of ethics to physics. (shrink)

We have now seen that, in what we call the mental world, Consciousness,- there are three grand classes of phenomena, the most familiar of all the facts with ...

Zen Buddhist Attitudes to War HIRATA Seiko IN ORDER FULLY TO UNDERSTAND the standpoint of Zen on the question of nationalism, one must first consider the ...

"Well-being," "welfare," "utility," and "quality of life," all closely related concepts, are at the center of morality, politics, law, and economics. Griffin's book, while primarily a volume of moral philosophy, is relevant to all of these subjects. Griffin offers answers to three central questions about well-being: what is the best way to understand it, can it be measured, and where should it fit in moral and political thought. With its breadth of investigation and depth of insight, this work holds significance (...) for philosophers as well as for those interested in political and economic theory and jurisprudence. (shrink)

The problem of personal identity is often said to be one of accounting for what it is that gives persons their identity over time. However, once the problem has been construed in these terms, it is plain that too much has already been assumed. For what has been assumed is just that persons do have an identity. A new interpretation of Hume's no-self theory is put forward by arguing for an eliminative rather than a reductive view of personal identity, and (...) by approaching the problem in terms of phenomenology, Buddhist psychology, and the idea of a constructed self-image. (shrink)

A lineage of prominent philosophers who have discussed the second-person relation can be regarded as advancing structural accounts. They posit that the second-person relation effects one transformative change to the structure of practical reasoning. In this paper, I criticise this orthodoxy and offer an alternative, substantive account. That is, I argue that entering into second-personal relations with others does indeed affect one's practical reasoning, but it does this not by altering the structure of one's agential thought, but by changing what (...) reasons can become available. The importance of second-personal thought for action is heterogenous. Second-person relations make possible the emergence of a wide variety of different kinds of practical reasons: creating some, revealing others. Recognising this diminishes the appeal of the traditional, structural accounts of the practical significance of such second-personal relations. Moving away from structural accounts facilitates a more thorough understanding of the intersubjective form of action. (shrink)

Every Thing Must Go aruges that the only kind of metaphysics that can contribute to objective knowledge is one based specifically on contemporary science as it ...

This paper is about the similarity between the appreciation of a piece of art, such as a cherished music album, and the loving appreciation of a person whom one knows well. In philosophical discussion about the rationality of love, the Qualities View (QV) says that love can be justified by reference to the qualities of the beloved. I argue that the oft-rehearsed trading-up objection fails to undermine the QV. The problems typically identified by the objection arise from the idea that (...) love-worthy qualities could be coarse-grained, when in fact they must be fine-grained. The analogy with appreciation of aesthetic qualities helps to draw out this point. Once the fine-grained nature of love-worthy qualities is properly understood, it is clear that critics of the QV cannot rely on the trading-up objection to motivate its rejection. Moreover, the paper’s core argument helps to illuminate the persistently aesthetic nature of interpersonal affections. (shrink)

We applaud the spirit of MacNeilage's attempts to better explain the evolution and cortical control of speech by drawing on the vast literature in nonhuman primate neurobiology. However, he oversimplifies motor cortical fields and their known individual functions to such an extent that he undermines the value of his effort. In particular, MacNeilage has lumped together the functional characteristics across multiple mesial and lateral motor cortex fields, inadvertantly creating two hypothetical centers that simply may not exist.