In a reflective and richly entertaining piece from 1979, Doug Hofstadter playfully imagined a conversation between ‘Achilles’ and an anthill (the eponymous ‘Aunt Hillary’), in which he famously explored many ideas and themes related to cognition and consciousness. For Hofstadter, the anthill is able to carry on a conversation because the ants that compose it play roughly the same role that neurons play in human languaging; unfortunately, Hofstadter’s work is notably short on detail suggesting how this magic might be achieved1. (...) Conversely in this paper - finally reifying Hofstadter’s imagination - we demonstrate how populations of simple ant-like creatures can be organised to solve complex problems; problems that involve the use of forward planning and strategy. Specifically we will demonstrate that populations of such creatures can be configured to play a strategically strong - though tactically weak - game of HeX (a complex strategic game).We subsequently demonstrate how tactical play can be improved by introducing a form of forward planning instantiated via multiple populations of agents; a technique that can be compared to the dynamics of interacting populations of social insects via the concept of meta-population. In this way although, pace Hofstadter, we do not establish that a meta-population of ants could actually hold a conversation with Achilles, we do successfully introduce Aunt Hillary to the complex, seductive charms of HeX. (shrink)

Upshot: Albeit mostly supportive of our work, the commentaries we received highlighted a few points that deserve additional explanation, with regard to the notion of learning in our model, the relationship between our model and the brain, as well as the notion of anticipation. This open discussion emphasizes the need for toy computer models, to fuel theoretical discussion and prevent business-as-usual from getting in the way of new ideas.

Context: Constructivist approaches to cognition have mostly been descriptive, and now face the challenge of specifying the mechanisms that may support the acquisition of knowledge. Departing from cognitivism, however, requires the development of a new functional framework that will support causal, powerful and goal-directed behavior in the context of the interaction between the organism and the environment. Problem: The properties affecting the computational power of this interaction are, however, unclear, and may include partial information from the environment, exploration, distributed processing (...) and aggregation of information, emergence of knowledge and directedness towards relevant information. Method: We posit that one path towards such a framework may be grounded in these properties, supported by dynamical systems. To assess this hypothesis, we describe computational models inspired from swarm intelligence, which we use as a metaphor to explore the practical implications of the properties highlighted. Results: Our results demonstrate that these properties may serve as the basis for complex operations, yielding the elaboration of knowledge and goal-directed behavior. Implications: This work highlights aspects of interaction that we believe ought to be taken into account when characterizing the possible mechanisms underlying cognition. The scope of the models we describe cannot go beyond that of a metaphor, however, and future work, theoretical and experimental, is required for further insight into the functional role of interaction with the environment for the elaboration of complex behavior. Constructivist content: Inspiration for this work stems from the constructivist impetus to account for knowledge acquisition based on interaction. (shrink)

Alison Gopnik and Andrew Meltzoff have argued for a view they call the ‘theory theory’: theory change in science and children are similar. While their version of the theory theory has been criticized for depending on a number of disputed claims, we argue that there is a fundamental problem which is much more basic: the theory theory is multiply ambiguous. We show that it might be claiming that a similarity holds between theory change in children and (i) individual scientists, (ii) (...) a rational reconstruction of a Superscientist, or (iii) the scientific community. We argue that (i) is false, (ii) is non-empirical (which is problematic since the theory theory is supposed to be a bold empirical hypothesis), and (iii) is either false or doesn’t make enough sense to have a truth-value. We conclude that the theory theory is an interesting failure. Its failure points the way to a full, empirical picture of scientific development, one that marries a concern with the social dynamics of science to a psychological theory of scientific cognition. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Bishop Berkeley Exorcises the Infinite: Fuzzy Consequences of Strict Finitism1 David M. Levy Introduction It all began simply enough when Molyneux asked the wonderful question whether a person born blind, now able to see, would recognize by sight what he knew by touch (Davis 1960). After George Berkeley elaborated an answer, that we learn to perceive by heuristics, the foundations ofcontemporarymathematics wereinruin. Contemporary mathematicians waved their hands and (...) changed the subject.2 Berkeley's answer received a much more positive response from economists. Adam Smith,in particular, seizedupon Berkeley's doctrine that welearn to perceive distance tobuild anelaborate system in which one learns to perceive one's self-interest.3 Perhaps because older histories of mathematics are a positive hindrance in helping us understand the importance of Berkeley's argument against infinitesimals,4 its consequences for economics have passed unnoticed. If infinitesimal numbers are ruled out, and we wish to maintain an algebra, then we rule out infinite numbers. This implication of Berkeley's argumenthas a dramatic implication for our understanding ofthe history ofideas about rule-directed action. Let me motivate this claim with a well-known historical problem. The social doctrine set forth by John Locke outside the Two Treatises depends critically upon individual belief about possible states of infinite pain or pleasure. The critical issue for the intolerance of atheism in Locke's system is his claim that without beUefin the infinite bliss of heaven forgone by a criminal, there is no reason to think a calculating individual will avoid crime.5 Locke's discussion is so different from the discussion of religion by David Hume and Smith. Here, questions of the substance of belief—the infinite worth of Heaven—have largely vanished.6 What happened between Locke and Hume-Smith? One answer is Pierre Bayle and Bernard Mandeville. Berkeley's doctrine that only the finite is perceived is, I think, a better answer. Out of sight, out ofmind. In this paper I propose to give a close look at the content and consequences ofBishop Berkeley's once famous Towards a New Theory ofVision. While there are other aspects ofBerkeley's work that attract Volume XVIII Number 2 511 DAVID M. LEVY attention from historians ofeconomics,7 1 shall claim that Berkeley's insight into human perception in the Theory of Vision is central to Adam Smith's attempt to found economic behaviour on the self-awareness of systematic illusion. There is no doubt that Smith finds that much ofhuman behaviour is characterized by illusion.8 The difficulty arises, or so it seems to me, from modern unwilUngness to beheve that illusion can be systematic. There are four pieces to my argument. First, we consider Berkeley's statementofwhat we shall call his doctrine ofstrict finitism in perception.9 Berkeley puts forward two postulates: 1) there exists some minimum perceptible quantity, and 2) distance is not perceived directly but by experience. Second, we define strict finitism and demonstrate that it translates into the claim that perception is fuzzy in a technical sense. If Berkeleian perception is fuzzy, then some modern criticism of Berkeley's strict finitism is based upon a simple misunderstandingofthe propertiesoffuzzyrelations. Thisis quite easy to set right. (Getting right the doctrine of those who implicitly take perception to be fuzzy—Adam Smith is my prime candidate—will be muchharder.)Third, wereconsiderBerkeley's dispute withMandeville on the role ofinfinite gain in choice. Here, we find Mandeville putting forward the Berkeleian position that if infinite amounts mattered, people would not behave as they do. Berkeley's position against Mandeville, however, seems to depend upon the supposition that infinite distance is sensible.10 Earlier, however, the position that Mandeville argued for was defended by Berkeley. Fourth, we ask why all this isn't well known. The debate between Berkeley and Mandeville has been well studied, as has been the link between Berkeley and the Scots. In fact, our work focuses on one aspect of Berkeley's work that led to his challenge of the contemporary foundations of the calculus. If sense is a matter of perception, and infinitesimals cannot be perceived, then they are quite literally nonsense. Armed with this insight, Berkeley refuted contemporary mathematics. Nevertheless, the calculus was too... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Bishop Berkeley Exorcises the Infinite: Fuzzy Consequences of Strict Finitism1 David M. Levy Introduction It all began simply enough when Molyneux asked the wonderful question whether a person born blind, now able to see, would recognize by sight what he knew by touch (Davis 1960). After George Berkeley elaborated an answer, that we learn to perceive by heuristics, the foundations ofcontemporarymathematics wereinruin. Contemporary mathematicians waved their hands and (...) changed the subject.2 Berkeley's answer received a much more positive response from economists. Adam Smith,in particular, seizedupon Berkeley's doctrine that welearn to perceive distance tobuild anelaborate system in which one learns to perceive one's self-interest.3 Perhaps because older histories of mathematics are a positive hindrance in helping us understand the importance of Berkeley's argument against infinitesimals,4 its consequences for economics have passed unnoticed. If infinitesimal numbers are ruled out, and we wish to maintain an algebra, then we rule out infinite numbers. This implication of Berkeley's argumenthas a dramatic implication for our understanding ofthe history ofideas about rule-directed action. Let me motivate this claim with a well-known historical problem. The social doctrine set forth by John Locke outside the Two Treatises depends critically upon individual belief about possible states of infinite pain or pleasure. The critical issue for the intolerance of atheism in Locke's system is his claim that without beUefin the infinite bliss of heaven forgone by a criminal, there is no reason to think a calculating individual will avoid crime.5 Locke's discussion is so different from the discussion of religion by David Hume and Smith. Here, questions of the substance of belief—the infinite worth of Heaven—have largely vanished.6 What happened between Locke and Hume-Smith? One answer is Pierre Bayle and Bernard Mandeville. Berkeley's doctrine that only the finite is perceived is, I think, a better answer. Out of sight, out ofmind. In this paper I propose to give a close look at the content and consequences ofBishop Berkeley's once famous Towards a New Theory ofVision. While there are other aspects ofBerkeley's work that attract Volume XVIII Number 2 511 DAVID M. LEVY attention from historians ofeconomics,7 1 shall claim that Berkeley's insight into human perception in the Theory of Vision is central to Adam Smith's attempt to found economic behaviour on the self-awareness of systematic illusion. There is no doubt that Smith finds that much ofhuman behaviour is characterized by illusion.8 The difficulty arises, or so it seems to me, from modern unwilUngness to beheve that illusion can be systematic. There are four pieces to my argument. First, we consider Berkeley's statementofwhat we shall call his doctrine ofstrict finitism in perception.9 Berkeley puts forward two postulates: 1) there exists some minimum perceptible quantity, and 2) distance is not perceived directly but by experience. Second, we define strict finitism and demonstrate that it translates into the claim that perception is fuzzy in a technical sense. If Berkeleian perception is fuzzy, then some modern criticism of Berkeley's strict finitism is based upon a simple misunderstandingofthe propertiesoffuzzyrelations. Thisis quite easy to set right. (Getting right the doctrine of those who implicitly take perception to be fuzzy—Adam Smith is my prime candidate—will be muchharder.)Third, wereconsiderBerkeley's dispute withMandeville on the role ofinfinite gain in choice. Here, we find Mandeville putting forward the Berkeleian position that if infinite amounts mattered, people would not behave as they do. Berkeley's position against Mandeville, however, seems to depend upon the supposition that infinite distance is sensible.10 Earlier, however, the position that Mandeville argued for was defended by Berkeley. Fourth, we ask why all this isn't well known. The debate between Berkeley and Mandeville has been well studied, as has been the link between Berkeley and the Scots. In fact, our work focuses on one aspect of Berkeley's work that led to his challenge of the contemporary foundations of the calculus. If sense is a matter of perception, and infinitesimals cannot be perceived, then they are quite literally nonsense. Armed with this insight, Berkeley refuted contemporary mathematics. Nevertheless, the calculus was too... (shrink)

Professor Richmond's reply t o m y article on Palatine Apollo is argued with his usual enthusiasm and cogency. This reply to him, which has been delayed by my departure for Australia, must begin with an expression of the respect that I feel for an antagonist far more able and experienced than I can claim to be. Indeed, it was while lecturing on Ovid, Tristia 3 that I first met Professor Richmond's masterly article on the Augustan Palatium . From this (...) article my enthusiasm for the subject began, and I know that Professor Richmond has always welcomed discussion and argument about the famous Augustan temple of Apollo on the Palatine. I can but join him in urging any who may have been interested by our discussion to study his original article which contains much more besides a discussion of the site of Apollo's temple. (shrink)

Professor Richmond's reply t o m y article on Palatine Apollo is argued with his usual enthusiasm and cogency. This reply to him, which has been delayed by my departure for Australia, must begin with an expression of the respect that I feel for an antagonist far more able and experienced than I can claim to be. Indeed, it was while lecturing on Ovid, Tristia 3 that I first met Professor Richmond's masterly article on the Augustan Palatium. From this article (...) my enthusiasm for the subject began, and I know that Professor Richmond has always welcomed discussion and argument about the famous Augustan temple of Apollo on the Palatine. I can but join him in urging any who may have been interested by our discussion to study his original article which contains much more besides a discussion of the site of Apollo's temple. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:BOOK REVIEWS 265 concluding chapter (pp. 150-52), Dr. Clair deals with "Comment lire l'oeuvre du P. Thomassin," providing much guidance to anyone who wishes to avail himself of the rich resources in Thomassin's writings. From the point of view of the history of philosophy, the most interesting aspects of Thomassin's thought seem to be (1) his "Cartesianism," that is, the extent to which he early imbibed Descartes' new ideas, (...) and played a role in the fusion of the views of Augustine, B6rulle, and Descartes that developed in the Oratory, (2) his attempt to find a viable theory of the nature of Grace somewhere between Arnauld and Malebranche, and (3) his efforts to formulate a philosophy of history within an Augustinian theology; a philosophy of history that would make historical research and understanding of genuine philosophical and religious value to man. Dr. Clair's too brief discussions indicate that Thomassin was definitely influenced by reading Descartes, but also that Thomassin was much too eclectic to be a Cartesian. With regard to the problem of Grace, where the Cartesian Arnauld fought with the semi-Cartesian Malebranche, Thomassin tried deftly to maintain an Augustinian position that was not quite as rigid as that of the Jansenists, nor as moderate as that of Malebranche (though Arnauld tried to use Thomassin's erudition and authority in his battles with Malebranche). Unfortunately Dr. Clair does not try to evaluate whether Thomassin really found a coherent and theologically acceptable middle-ground between the two antagonists. On the subject of the philosophy of history, Thomassin's views seem most interesting (at least to this reviewer). The short text that Dr. Clair includes on the difference of history from science reveals Thomassin trying to show that the investigation and comprehension of temporal particulars can have significant value for man's understanding of man and that there can be genuine certainty about past facts. Thomassin was writing in the period when modern historical method and outlook were born, when historical study changed from chronicles and ammunition in theological and political disputes to a basic way of understanding human nature. Those concerned with the role of Bayle, Hume, Gibbon, and Vico in developing an historical methodology and a rationale for art historical approach to human problems might well profit from considering Thomassin's writings in this area, and the influence they had on modern historiography and philosophies of history. Dr. Clair's short work certainly helps in filling a lacuna in our picture of the seventeenth century. It also makes one wish he had done more, and had provided a "complete" study of Thomassin's thought and influence. That, perhaps, is one of the major purposes of this new series, in that it will lead scholars to looking into the more hidden portions of the period, and will lead them to filling out in more detail and depth the history of the rise and fall of modern philosophy. It is to be hoped that future volumes in this series will continue to whet our appetites for further investigations, and will transform more of the names we run across into figures about whom we have some information and from whom we can still learn something. RICHARD H. POPKIN University of California, San Diego Berkeley's Theory of Vision..4 Critical Examination of Bishop Berkeley's Essay towards a New Theory of Vision. By D. M. Armstrong. (Melbourne: University Press; London and N. Y.: Cambridge University Press, 1960. Pp. viii + 106. $4.50). Berkeley's brilliant though disconcerting Essay has been rather neglected for some time, except for the able studies of C. M. Turbayne of Rochester University (N. Y.). Armstrong's book is welcome for that reason, also for its freshness, clearness, and rich brevity. A1- 266 HISTORY OF PHILOSOPHY though a slim volume, it is packed with close yet lucid argumentation, conducted throughout with good manners, and throughout exploratory, clarifying problems, exposing logical and empirical difficulties, not grandly telling us what the truth is but leaving us in a better position to carry on the exploration ourselves. It is an exemplary piece of philosophical discussion. He clears his ground by noting that the Essay, so far as... (shrink)

_Purpose._ The purpose is to justify the validity of interpreting Descartes’ teachings as an enquiry into the search for forms and means of improving human nature, which implies a focus on the way he understands the openness of knowledge and education. The problem is considered from the perspective of representatives of university communities (teachers and librarians), historically included in the communication structure and system of the institution, including through the creation, management, use, preservation and dissemination of knowledge. _Theoretical basis._ One (...) of the tenets of Descartes’ teachings is his desire to improve the human being. For our consideration, it is fundamentally important that Descartes uses "knowledge" not only in a narrow sense – as natural scientific knowledge, but also in a broader sense. In the context of the theme of the study, the most important case is when the thinker recalls the knowledge that every person experiences without referring to philosophy. It is this knowledge that, for Descartes, is key in resolving the central problem of his ethics – how can human nature be perfected? For our consideration of Descartes’ key points, it is fair to focus on the manifestation of the phenomenon of altruism in Descartes’ philosophy and on the representative fact of his inner openness – his willingness to engage in dialogue. He appreciates and encourages his interlocutors to turn to books, which are a form of representation of the vivid personalities of their authors. _Originality._ For the first time in the research literature, the thesis of René Descartes as one of the forerunners of the open knowledge system is substantiated. The arguments are given for the validity of Descartes’ interpretation of the demand of his own epoch for the search of effective forms of human improvement. _Conclusions._ The idea of justification of Descartes’ philosophical legacy as a predictor of open knowledge became possible under the condition of paying attention to the anthropological turn he made and finding substantive analogues of openness, including open education. Drawing on Christianity as the basis for altruism, Descartes demonstrates a caring attitude towards the achievements of previous generations on the path of personal self-development. His attention is rightly drawn to education and books as representations of vibrant personalities. Their authentic and productive assimilation is possible only under the condition of a caring attitude towards the public good, which involves the intellectual volunteering of teachers and librarians. It is about self-realization through altruistic self-improvement, i.e. intellectual charity, which is especially evident today during martial law in Ukraine and is voluntary, conscious and free work for the benefit of others. (shrink)

Patient competence, defined as the ability to reason, appreciate, understand, and express a choice is rarely discussed in patients with obsessive compulsive disorder, and coercive measures are seldom used. Nevertheless, a psychiatrist of psychologist may doubt whether OCD patients who refuse treatment understand their disease and the consequences of not being treated, which could result in tension between respecting the patient’s autonomy and beneficence. The purpose of this article is to develop a notion of competence that is grounded in clinical (...) practice and corresponds with the experiences of patients with obsessions and/or compulsions. We present a naturalistic case study giving both the patient’s and the therapist’s perspective based on in-depth interviews and a narrative analysis. The case study shows that competence is not merely an assessment by a therapist, but also a co-constructed reality shaped by the experiences and stories of patient and therapist. The patient, a medical student, initially told her story in a restitution narrative, focusing on cognitive rationality. Reconstructing the history of her disease, her story changed into a quest narrative where there was room for emotions, values and moral learning. This fitted well with the therapist’s approach, who used motivational interventions with a view to appealing to the patient’s responsibility to deal with her condition. We conclude that in practice both the patient and therapist used a quest narrative, approaching competence as the potential for practical reasoning to incorporate values and emotions. (shrink)

Peace; Egypt; education conditions; history.

Professional identity and competent ethical behaviors of nursing students are commonly developed through curricular inclusion of professional nursing values education. Despite the enactment of this approach, nursing students continue to express difficulty in managing ethical conflicts encountered in their practice. This descriptive correlational study explores the relationships between professional nursing values, self-esteem, and ethical decision making among senior baccalaureate nursing students. A convenience sample of 47 senior nursing students from the United States were surveyed for their level of internalized professional (...) nursing values (Revised Professional Nursing Values Scale), level of self-esteem (Rosenberg’s Self-Esteem Scale), and perceived level of confidence in ethical decision making. A significant positive relationship (p < 0.05) was found between nursing students’ professional nursing values and levels of self-esteem. The results of this study can be useful to nursing educators whose efforts are focused on promoting professional identity development and competent ethical behaviors of future nurses. (shrink)

The problem of representing a single localized particle has played a crucial role in the historical development of quantum theories. In particular, the failure to construct a relativistically invariant position eigenstate was a contributing factor in the demise of the so-called relativistic quantum mechanics, in favor of quantum field theories. Nevertheless, non-locality which stems from standard accounts of Single-particle localization still presents itself as a problem in the form of Gerhard Hegerfeldt's eponymous theorem of 1974. Accepting that a link may (...) be maintained between invariance and 'objectivity,' it is shown how Hegerfeldt's paradoxical result arises in relativistic theories from a failure of objectivity of localization-the so-called 'Jericho effect'. (shrink)

Patients in a vegetative state/ unresponsive wakefulness syndrome (VS/UWS) pose ethical dilemmas to those involved. Many conflicts occur between professionals and families of these patients. In the Netherlands physicians are supposed to withdraw life sustaining treatment once recovery is not to be expected. Yet these patients have shown to survive sometimes for decades. The role of the families is thought to be important. The aim of this study was to make an inventory of the professional perspective on conflicts in long-term (...) care of patients in VS/UWS. A qualitative study of transcripts on 2 Moral Deliberations (MD’s) in 2 cases of patients in VS/UWS in long-term care facilities. Six themes emerged: 1) Vision on VS/UWS; 2) Treatment and care plan; 3) Impact on relationships; 4) Feelings/attitude; 5) Communication; 6) Organizational aspects. These themes are related to professionals and to what families had expressed to the professionals. We found conflicts as well as contradictory feelings and thoughts to be a general feature in 4 of these themes, both in professionals and families. Conflicts were found in several actors: within families concerning all 6 themes, in nurse teams concerning the theme treatment and care plan, and between physicians concerning all 6 themes. Different visions, different expectations and hope on recovery, deviating goals and contradictory feelings/thoughts in families and professionals can lead to conflicts over a patient with VS/UWS. Key factors to prevent or solve such conflicts are a carefully established diagnosis, clarity upon visions, uniformity in treatment goals and plans, an open and empathic communication, expertise and understanding the importance of contradictory feelings/thoughts. Management should bridge conflicts and support their staff, by developing expertise, by creating stability and by facilitating medical ethical discourses. Shared compassion for the patient might be a key to gain trust and bridge the differences from non-shared to shared decision making. (shrink)

The four-year wrangle over the ownership of what was then thought to have been the largest known meteorite, recognized near Melbourne in 1860, provides a fine-grained example of the interaction between scientific internationalism, metropolitan appetite for specimens, and colonial civic pride.

In lieu of an abstract, here is a brief excerpt of the content:BOOK REVIEWS 265 concluding chapter (pp. 150-52), Dr. Clair deals with "Comment lire l'oeuvre du P. Thomassin," providing much guidance to anyone who wishes to avail himself of the rich resources in Thomassin's writings. From the point of view of the history of philosophy, the most interesting aspects of Thomassin's thought seem to be (1) his "Cartesianism," that is, the extent to which he early imbibed Descartes' new ideas, (...) and played a role in the fusion of the views of Augustine, B6rulle, and Descartes that developed in the Oratory, (2) his attempt to find a viable theory of the nature of Grace somewhere between Arnauld and Malebranche, and (3) his efforts to formulate a philosophy of history within an Augustinian theology; a philosophy of history that would make historical research and understanding of genuine philosophical and religious value to man. Dr. Clair's too brief discussions indicate that Thomassin was definitely influenced by reading Descartes, but also that Thomassin was much too eclectic to be a Cartesian. With regard to the problem of Grace, where the Cartesian Arnauld fought with the semi-Cartesian Malebranche, Thomassin tried deftly to maintain an Augustinian position that was not quite as rigid as that of the Jansenists, nor as moderate as that of Malebranche (though Arnauld tried to use Thomassin's erudition and authority in his battles with Malebranche). Unfortunately Dr. Clair does not try to evaluate whether Thomassin really found a coherent and theologically acceptable middle-ground between the two antagonists. On the subject of the philosophy of history, Thomassin's views seem most interesting (at least to this reviewer). The short text that Dr. Clair includes on the difference of history from science reveals Thomassin trying to show that the investigation and comprehension of temporal particulars can have significant value for man's understanding of man and that there can be genuine certainty about past facts. Thomassin was writing in the period when modern historical method and outlook were born, when historical study changed from chronicles and ammunition in theological and political disputes to a basic way of understanding human nature. Those concerned with the role of Bayle, Hume, Gibbon, and Vico in developing an historical methodology and a rationale for art historical approach to human problems might well profit from considering Thomassin's writings in this area, and the influence they had on modern historiography and philosophies of history. Dr. Clair's short work certainly helps in filling a lacuna in our picture of the seventeenth century. It also makes one wish he had done more, and had provided a "complete" study of Thomassin's thought and influence. That, perhaps, is one of the major purposes of this new series, in that it will lead scholars to looking into the more hidden portions of the period, and will lead them to filling out in more detail and depth the history of the rise and fall of modern philosophy. It is to be hoped that future volumes in this series will continue to whet our appetites for further investigations, and will transform more of the names we run across into figures about whom we have some information and from whom we can still learn something. RICHARD H. POPKIN University of California, San Diego Berkeley's Theory of Vision..4 Critical Examination of Bishop Berkeley's Essay towards a New Theory of Vision. By D. M. Armstrong. (Melbourne: University Press; London and N. Y.: Cambridge University Press, 1960. Pp. viii + 106. $4.50). Berkeley's brilliant though disconcerting Essay has been rather neglected for some time, except for the able studies of C. M. Turbayne of Rochester University (N. Y.). Armstrong's book is welcome for that reason, also for its freshness, clearness, and rich brevity. A1- 266 HISTORY OF PHILOSOPHY though a slim volume, it is packed with close yet lucid argumentation, conducted throughout with good manners, and throughout exploratory, clarifying problems, exposing logical and empirical difficulties, not grandly telling us what the truth is but leaving us in a better position to carry on the exploration ourselves. It is an exemplary piece of philosophical discussion. He clears his ground by noting that the Essay, so far as... (shrink)