This paper puts forward the hypothesis that consciousness might be linked to matter in a way which is more sophisticated than the traditional macroscopic Cartesian hypothesis suggests.Advances in the biophysics of the nervous system, not only on the level of its macroscopic functioning but also on the level of individual ion channels, have made the question of how finely consciousness is tied to matter and its dynamics more important. Quantum mechanics limits the attainable resolution and puts into doubt (...) the idea of an infinitely fine-woven attachment. A recent approach to physics rekindles such a rationalist hope. Endophysics focuses on the global implications of microscopic computer simulations of chemical and biophysical processes. A complete artificial universe can be set up in the computer. It produces non-classical and nonlocal effects inside — on the interface that exists between an internal observer (fluid neuron) and the rest of the world. This interface is finer than any brain property to which the status of the mind-body interface has been attributed hitherto. A new class of experiments becomes possible in the artificial world and, by analogy, in the real world. Magnetic resonance imaging experiments, routinely performed under open-loop conditions, can be repeated under psychophysical (closed-loop) conditions — in search for microscopically induced changes in the perceived and measured structure of the world. (shrink)

I read Stefan Collini’s What are Universities For? last week with very mixed feelings. In the past, I’ve much admired his polemical essays on the REF, “impact”, the Browne Report, etc. in the London Review of Books and elsewhere: they speak to my heart. If you don’t know those essays, you can get some of their flavour from his latest article in the Guardian yesterday. But I found the book a disappointment. Perhaps the trouble is that Collini is too decent, (...) too high-minded, has too unrealistically exalted a view about what actually happens in universities which is too coloured by attitudes appropriate to the traditional humanities. And he is optimistic to the point of fantasy if he thinks that people are so susceptible to “the romance of ideas and the power of beauty” that they will want, or can be brought to want, lots and lots of universities in order to promote the ideas (as if they would suppose that the task of “conserving, understanding, extending and handing on to subsequent generations the intellectual, scientific, and artistic heritage of mankind” was clearly ill-served when there were only forty universities in England, as opposed to a hundred and whatever). (shrink)

This book offers a theory of how human conceptual life begins, and shows how perceptual information becomes transformed into concepts. Drawing on extensive research, Mandler describes the development of preverbal concept formation, inductive inference, and recall, and explains how these processes form the conceptual basis for language and adult thought.

Quantification, Negation, and Focus: Challenges at the Conceptual-Intentional Semantic Interface Tista Bagchi National Institute of Science, Technology, and Development Studies (NISTADS) and the University of Delhi Since the proposal of Logical Form (LF) was put forward by Robert May in his 1977 MIT doctoral dissertation and was subsequently adopted into the overall architecture of language as conceived under Government-Binding Theory (Chomsky 1981), there has been a steady research effort to determine the nature of LF in language in light of (...) structurally diverse languages around the world, which has ultimately contributed to the reinterpretation of LF as a Conceptual-Intentional (C-I) interface level between the computational syntactic component of the faculty of language and one or more interpretive faculties of the human mind. While this has opened up further possibilities of research in phenomena such as quantifier scope and scope interactions between negation, quantification, and focus, it has also given rise to a few real challenges to linguistic theory as well. Some of these are: (i) the split between lexical meaning – a matter supposedly belonging to the phase-wise selection of lexical arrays – and issues of semantic interpretation that arise purely from binding and scope phenomena (Mukherji 2010); (ii) partially relatedly, the level at which theta role assignment can be argued to take place, an issue that is taken up by me in Bagchi (2007); and (iii) how supposedly “pure” scopal phenomena relating to quantifiers, negation, and emphasizing expressions such as only and even (comparable to, e.g., Urdu/Hindi hii and bhii, Bangla –i and –o) also have dimensions of both focus and discourse reference. While recognizing all of these challenges, this talk aims to highlight particularly challenge (iii), both in terms of scholarship in the past and for the rich prospects for research on languages of south Asia with the semantics of quantification, negation, and focus in view. The scholarship of the past that I seek to relate this issue to is where, parallel to (and largely independently of) the research on LF that had been happening, Barwise and Cooper were developing their influential view of noun phrases as generalized quantifiers, culminating in their key 1981 article “Generalized Quantifiers and Natural Language” while, independently, McCawley, in his 1981 book Everything that Linguists have Always Wanted to Know about Logic, established through argumentation that all noun phrases semantically behave like generalized quantified expressions (further elaborated by him in the second – 1994 – revised edition of his book). I seek to demonstrate, based on limited data analysis from selected languages of south Asia, that our current understanding of quantification, negation, and focus under the Minimalist view owes something significant to the two major, but now largely marginalized, works of scholarship, and that for the way forward it is essential to adopt a more formal-semantic approach as adopted by them and also by later works such as Denis Bouchard’s (1995) The Semantics of Syntax, Mats Rooth’s work on focus (e.g., Rooth 1996, “Focus” in Shalom Lappin’s Handbook of Contemporary Semantic Theory), Heim and Kratzer’s Semantics in Generative Grammar (1998), and Yoad Winter’s (2002) Linguistic Inquiry article on semantic number, to cite just a few instances. (shrink)

This volume of essays examines the problem of mind, looking at how the problem has appeared to neuroscientists from classical antiquity through to contemporary times. Beginning with a look at ventricular neuropsychology in antiquity, this book goes on to look at Spinozan ideas on the links between mind and body, Thomas Willis and the foundation of Neurology, Hooke’s mechanical model of the mind and Joseph Priestley’s approach to the mind-body problem. The volume offers a chapter on (...) the 19th century Ottoman perspective on western thinking. Further chapters trace the work of nineteenth century scholars including George Henry Lewes, Herbert Spencer and Emil du Bois-Reymond. The book covers significant work from the twentieth century, including an examination of Alfred North Whitehead and the history of consciousness, and particular attention is given to the development of quantum consciousness. Chapters on slavery and the self and the development of an understanding of Dualism bring this examination up to date on the latest 21st century work in the field. At the heart of this book is the matter of how we define the problem of consciousness itself: has there been any progress in our understanding of the working of mind and brain? This work at the interface between science and the humanities will appeal to experts from across many fields who wish to develop their understanding of the problem of consciousness, including scholars of Neuroscience, Behavioural Science and the History of Science. (shrink)

This article takes off from Johan van Benthem’s ruminations on the interface between logic and cognitive science in his position paper “Logic and reasoning: Do the facts matter?”. When trying to answer Van Benthem’s question whether logic can be fruitfully combined with psychological experiments, this article focuses on a specific domain of reasoning, namely higher-order social cognition, including attributions such as “Bob knows that Alice knows that he wrote a novel under pseudonym”. For intelligent interaction, it is important (...) that the participants recursively model the mental states of other agents. Otherwise, an international negotiation may fail, even when it has potential for a win-win solution, and in a time-critical rescue mission, a software agent may depend on a teammate’s action that never materializes. First a survey is presented of past and current research on higher-order social cognition, from the various viewpoints of logic, artificial intelligence, and psychology. Do people actually reason about each other’s knowledge in the way proscribed by epistemic logic? And if not, how can logic and cognitive science productively work together to construct more realistic models of human reasoning about other minds? The paper ends with a delineation of possible avenues for future research, aiming to provide a better understanding of higher-order social reasoning. The methodology is based on a combination of experimental research, logic, computational cognitive models, and agent-based evolutionary models. Keywords Epistemic logic - Cognitive science - Intelligent interaction - Cognitive modeling. (shrink)

This article takes off from Johan van Benthem’s ruminations on the interface between logic and cognitive science in his position paper “Logic and reasoning: Do the facts matter?”. When trying to answer Van Benthem’s question whether logic can be fruitfully combined with psychological experiments, this article focuses on a specific domain of reasoning, namely higher-order social cognition, including attributions such as “Bob knows that Alice knows that he wrote a novel under pseudonym”. For intelligent interaction, it is important (...) that the participants recursively model the mental states of other agents. Otherwise, an international negotiation may fail, even when it has potential for a win-win solution, and in a time-critical rescue mission, a software agent may depend on a teammate’s action that never materializes. First a survey is presented of past and current research on higher-order social cognition, from the various viewpoints of logic, artificial intelligence, and psychology. Do people actually reason about each other’s knowledge in the way proscribed by epistemic logic? And if not, how can logic and cognitive science productively work together to construct more realistic models of human reasoning about other minds? The paper ends with a delineation of possible avenues for future research, aiming to provide a better understanding of higher-order social reasoning. The methodology is based on a combination of experimental research, logic, computational cognitive models, and agent-based evolutionary models. (shrink)

Despite substantial efforts by many researchers, we still have no scientific theory of how brain activity can create or be con- scious experience. This is troubling since we have a large body of correlations between brain activity and consciousness, correlations normally assumed to entail that brain activity creates conscious experience. Here I explore a solution to the mind-body problem that starts with the converse assumption: these correlations arise because consciousness creates brain activity and indeed creates all objects and properties (...) of the physical world To this end, I develop two theses. The multimodal user interface theory of perception states that perceptual experiences do not match or approximate properties of the objective world but instead provide a simplified species-specific, user interface to that world Conscious realism states that the objective world consists of conscious agents and their experiences; these can be mathematically modeled and em- pirically explored in the normal scientific manner. (shrink)

Scientific exploration and thus our knowledge about the outside world is subject to the conditions of our experience.These conditions are condensed here into an interface model which,besides being physical,has an additional interface structure not reducible to physics. We suggest that this structure can dynamically be characterized by separate modes.Their selection and operation presupposes free will and a rudimentary concept of time and space. Based on some analogies with quantum networks it is argued that the 'observed' gets 'dressed'as a (...) consequence of the observing. Interface dynamics and system dynamics supplement each other without over- determination. (shrink)

The Radical Enactive/embodied view of Cognition, or REC, claims that all cognition is a matter of skilled performance. Yet REC also makes a distinction between basic and content-involving cognition, arguing that the development of basic to content-involving cognition involves a kink. It might seem that this distinction leads to problematic gaps in REC’s story. We address two such alleged gaps in this paper. First, we identify and reply to the concern that REC leads to an “interface problem”, according (...) to which REC has to account for the interaction of two minds co-present in the same cognitive activity. We emphasise how REC’s view of content-involving cognition in terms of activities that require particular sociocultural practices can resolve these interface concerns. The second potential problematic gap is that REC creates an unjustified difference in kind between animal and human cognition. In response, we clarify and further explicate REC’s notion of content, and argue that this notion allows REC to justifiably mark the distinction between basic and content-involving cognition as a difference in kind. We conclude by pointing out in what sense basic and content-involving cognitive activities are the same, yet different. They are the same because they are all forms of skilled performance, yet different as some forms of skilled performance are genuinely different from other forms. (shrink)

In this book, which contains several of his key papers as well as new material, he focuses on the problem of consciousness and explains how quantum mechanics...

In this book, Hodgson presents a clear and compelling case against today's orthodox mechanistic view of the brain-mind, and in favor of the view that "the mind matters." In the course of the argument he ranges over such topics as consciousness, informal reasoning, computers, evolution, and quantum indeterminancy and non-locality. Although written from a philosophical viewpoint, the book has important implications for the sciences concerned with the brain-mind problem. At the same time, it is largely non-technical, and (...) thus accessible to the non-specialist reader. (shrink)

Written for students, Mind, Matter, and Nature presumes no prior philosophical training on the part of the reader. The book nevertheless holds the arguments discussed to rigorous standards and is conversant with recent literature, thus making it useful as well to more advanced students and professionals interested in a resource on Thomistic hylomorphism in the philosophy of mind.

I discuss the bearing on the mind-body problem of some general characteristics of living systems, including the physical basis of metabolism and the relation between living activity and cognitive capacities in simple organisms. I then attempt to describe stages in the history of animal life important to the evolution of subjective experience. Features of the biological basis of cognition are used to criticize arguments against materialism that draw on the conceivability of a separation between mental and physical. I also (...) argue against commonly held views about the "multiple realizability" of mental states of the kind seen in humans. The aim of the paper is to reconfigure and narrow the "explanatory gap" between mental and physical. (shrink)

Mind, Matter, and Method was first published in 1966. Minnesota Archive Editions uses digital technology to make long-unavailable books once again accessible, and are published unaltered from the original University of Minnesota Press editions. This volume of twenty-six essays by as many contributors is published in honor of Herbert Feigl, professor of philosophy at the University of Minnesota and director of the Minnesota Center for the Philosophy of Science. Though the majority of the contributors are philosophers, there are (...) also -- as benefits Mr. Feigl's varied intellectual interests -- representatives of psychology, psychoanalysis, and physics. The first group of ten essays deals with the philosophy of mind, particularly with the mind-body problem, to which Mr. Feigl has devoted much attention. The eleven essays in the second part are concerned with problems of philosophical method, especially with induction and confirmation. The third part is comprised of five essays on the philosophy of the physical sciences. A biographical sketch of Mr. Feigl and a bibliography of his writings are also provided. (shrink)

This accessible and easy-to-follow book offers a new approach to consciousness. The author’s eclectic style combines new physics-based insights with those of analytical philosophy, phenomenology, cognitive science and neuroscience. He proposes a view in which the mechanistic framework of classical physics and neuroscience is complemented by a more holistic underlying framework in which conscious experience finds its place more naturally.

The most fundamental issue of the neurosciences is the question of how or whether the mind and the body can interact with each other. It has recently been suggested in several studies that current neuroimaging evidence supports a view where the mind can have a well-documented causal influence on various brain processes. These arguments are critically analyzed here. First, the metaphysical commitments of the current neurosciences are reviewed. According to both the philosophical and neuroscientific received views, mental states (...) are necessarily neurally based. It is argued that this leaves no room for a genuine interaction of the mental and the neural. Second, it is shown how conclusions drawn from recent imaging studies are in fact compatible with the fully physicalistic notion of mental causation and how they can thus be easily accommodated to the received view. The fallacious conclusions are argued to be a result of an overly vague grasping of the conceptual issues involved. The question of whether the fundamental physical principles exclude outright the ability of mental states to have causal influence on the physical world is also addressed and the reaction of appealing to the apparent loophole provided by quantum physics is assessed. It is argued that linking psychology to quantum physics contradicts many basic tenets of the current neurosciences and is thus not a promising line of study. It is concluded that the interactionist hypothesis benefits from neither conceptual nor empirical support. (shrink)

In this paper, I propose a framework that supports both free will and anomalous mind-matter interaction (psychokinesis). I begin by considering the argument by the physicist Sean Carroll that the laws of physics as we understand them rule out psychokinesis (and other modes of psi). I find Carroll’s claims problematic, in part due to what I believe are misunderstandings of arguments borrowed from David Hume. I proceed to consider a more dispositional notion of causality (in contrast to one (...) characterized by universal and necessary laws) which I argue is more hospitable to both psychokinesis and free will. I then incorporate recent work from the philosophy of mind and science to arrive at a framework that supports both real volition and psychokinesis, which I argue are intimately linked. This approach is fundamentally dispositional, but grounded in an ontologically prior field of awareness and potentiality. I also consider that the regularities (or causal natures) we observe in our physical world are ultimately supported by what we might term teleological “intentions” within a nonlocal, mind-like quantum ground. (shrink)

Theo C. Meyering, in “Mind Matters: Physicalism and the Autonomy of the Person,” takes yet a third approach to the issue of reduction. He states that “if (true, downward) mental causation implies nonreducibility [as Stoeger and Murphy argue] and physicalism implies the converse, it is hard to see how these two views could be compatible.” Meyering distinguishes three versions of reductionism: radical (industrial strength) physicalism; ideal (regular strength) physicalism, and mild or token physicalism. Radical physicalism asserts that all special (...) sciences are reducible to physics in the sense that their laws can be deduced via bridge laws from those of physics. Ideal physicalism asserts that while it is practically impossible to reduce the special sciences, such reduction would be possible were there an ideally complete physics" (Note: This distinction parallels Stoeger’s recognition that epistemological reducibility is relative to the meaning of “laws of nature). Token physicalism is ontologically reductionist: there are no events that are not “token-identical” with some physical event or other (Note: See above, sec. 3.3). However, there are no identities between higher-level and lower- level types of events; consequently some events described by the special sciences have no physical explanation at all. -/- All of these reductionist positions are to be contrasted with compositional (milder than mild) physicalism, which asserts that some higher-level events are not even token-identical with physical events because the higher-level event (say, a crash in the stock market) is constituted by innumerable physical particulars in all sorts of states and interactions. -/- Meyering then surveys some of the existing arguments for the nonreducibility of the special sciences. One of the most important is the argument from multiple realizability. The claim is that economics, for example, is not reducible to physics because economic concepts (for example, monetary exchange) are “wildly multiply realizable” (for example, using coins, strings of wampum, signing a check). Thus, there can be no bridge laws and no reduction. Such an argument, however, only cuts against radical physicalism, not the weaker (and a priori more plausible) ideal physicalism. -/- A stronger argument for the indispensability of special-science explanations is based on the role of functional explanations. For example, the functional description of aspirin as an analgesic is in some instances a more useful explanation of its causal role (relieving a headache) than is its description as the chemical level. -/- Meyering’s own contribution focuses neither on multiple realizability of supervenient properties nor on multiple “fillers” of functional roles, but on “multiple supervenience.” In particular, a single subvenient state of affairs (for example, a cloud of free electrons permeating the metal of which a ladder is constructed) may realize a variety of supervenient dispositional properties (in this case, electrical conductivity, thermal conductivity, opacity). An explanation (say, of the cause of a deadly accident) requires reference to the dispositional property (electrical conductivity), not merely to the subvenient property. Meyering argues that it is this possibility of multiple supervenience, not multiple realizability, that gives arguments against reduction based on functional properties their real force. Downward causation, then, can be understood in terms of selective activation of one of several dispositional properties of a lower-level state, and thus can be assigned a stable place in our picture of how the world is organized without upsetting our conception of physics as constituting a closed and complete system of physical events. (shrink)

Some aspects of the problem of measurement in quantum theory are treated. We stress that the problem is both physical and conceptual, that the physical problem has been solved and the conceptual one is inherent in quantum theory. We also deal with some remarks made by Wigner concerning physics and the explanation of life, and present alternative positions on the mind-matter relationship within a deterministic framework, as we see them.

How do we ensure that future generally intelligent AI share our values? This is the value-alignment problem. It is a weighty matter. After all, if AI are neutral with respect to our wellbeing, or worse, actively hostile toward us, then they pose an existential threat to humanity. Some philosophers have argued that one important way in which we can mitigate this threat is to develop only AI that shares our values or that has values that ‘align with’ ours. However, (...) there is nothing to guarantee that this policy will be universally implemented—in particular, ‘bad actors’ are likely to flout it. In this paper, I show how the predictive processing model of the mind, currently ascendant in cognitive science, may ameliorate the value-alignment problem. In essence, I argue that there are a plurality of reasons why any future generally intelligent AI will possess a predictive processing cognitive architecture (e.g. because we decide to build them that way; because it is the only possible cognitive architecture that can underpin general intelligence; because it is the easiest way to create AI.). I also argue that if future generally intelligent AI possess a predictive processing cognitive architecture, then they will come to share our pro-moral motivations (of valuing humanity as an end; avoiding maleficent actions; etc.), regardless of their initial motivation set. Consequently, these AI will pose a minimal threat to humanity. In this way then, I conclude, the value-alignment problem is significantly ameliorated under the assumption that future generally intelligent AI will possess a predictive processing cognitive architecture. (shrink)

Animal people are usually confident that Cartesianism is something of the past and that modern science clearly establishes that animals are sentient beings. But actually the scientific status of sentience is anything but firmly established. Not only is the subjective point of view absent from current science; it is precluded by construction from our fundamental realms of knowledge. Physics — the mother-science once we reject Cartesian dualism — is currently unable to include sentience in its account of the world. A (...) large part of the philosophy of mind describes a mindless mind, from which subjectivity — feeling, qualia — has been stripped, leaving only in place functional relations. This situation paves the way for discourses in which sentience seems to escape the realm of knowledge to fall into that of private beliefs, which individuals can choose as freely as their religion. This is a real obstacle to having animal sentience taken seriously; as such it has been largely underestimated. We believe it necessary for the movement for animals to understand that it cannot by-pass the “mind-matter” problem. We must not allow the existence and relevance of animal sentience to be denied in the name of science. One path we are contemplating is a “Declaration on Sentience” in which scientists and other thinkers would subscribe to the following assertion: sentience is an objective reality of the world and belongs to the realm of science. Despite the current intractability of the “mind-matter” problem, we do have something on our side. Although we cannot prove the reality of sentience, we can show it impossible for anyone to disbelieve in it — just as no one can really disbelieve in the reality of the physical world. We thus have enough reasons to reject the main ways in which sentience is denied or dismissed in many realms of current philosophy or science. These reasons are based on our own situation as sentient and deliberative beings. (shrink)

The development of a metaphysics of actuality is reconstructed from Plato through Bergson to capitalize on Bergson's suggestion that mind and matter can be understood as inversions of each other, or as respectively a centering and an extending of forms. This view avoids the pitfalls of reductive monism and disjunctive dualism: it is dyadic (cognizant at once of mind-matter difference and of the unity of reality), symmetrical (not apt to close off prematurely our reckoning with complexity (...) and change, on either side), and correlational (able to track relations of form, energy, and sequence between mental and material items). (shrink)

The “Mind Matters” case study presents an opportunity for students in a wide range of courses such as business ethics, organizational behavior, leadership, marketing, and strategy to recognize and contemplate the difficult planning, the ethical challenges, and the high level of creativity necessary in many business decisions when bringing a new product or service to market. Also, this case study encourages its readers to formulate solutions and provide answers for complexproblems fraught with ethical dilemmas.

The great divide of modern thought is whether mind is real or naught. The conceit that either mind is reducible to matter or that mind is utterly ethereal is rooted in a mind-versus-matter dichotomy that can be characterized as the modern error, a fatally flawed fallacy rooted in the philosophy and culture of nominalism. A Peircean semiotic outlook, applied to an understanding of social life, provides a new and full-bodied understanding of semiosis as the (...) bridge between mind and matter, and human biology and culture. I begin by first delineating the false divide and showing Charles Sanders Peirce’s alternative to it, then explore the implications of a semiotic approach to mind as trans-action, then consider the self-transcending nature of the human body-mind. Finally I outline my ecological, biosemiotic account of mind, which reveals that, indeed, mind matters, and in ways that unexpect-edly resemble the forms of animism that characterized the hunting-gathering foragers through whom we anatomically modern humans emerged. (shrink)

This piece continues ideas developed in my essay, Mind Matters, through responding to the critique of that essay by Peter K. Manning. Manning cannot conceive that human conduct involves full-bodied semiosis rather than disembodied conceptualism, and that the study of human signification requires a full-bodied understanding. The ancient Greek root phren, basis for the concept of phronesis, is rooted in the heart-lungs-solar plexus basis of bodily awareness, and provides a metaphor for a discussion of bio-developmental, biosemiotic capacities as crucial (...) for human culture. Manning’s use of Wittgenstein is contrasted with the outlook of Charles Peirce. The intense attunement to and reverence for animals and plants in hunter-gatherer peoples is more than some conceptual collective representations system or interaction order or psychological belief system, explainable by Durkheim or Goffman, or Jung’s universal structure of the “collective unconscious,” or by neural net theory. It exemplifies how those peoples are in real learning relationships to the instinctive intelligence of their habitats, deep learning expressed not only in trial-and-error experience but also in the sense of wonder, communicated in ritual life. Mind is found literally in those transactions, not in isolate brains or disembodied conceptualism. (shrink)

This volume of twenty-six essays by as many contributors is published in honor of Herbert Feigl, professor of philosophy at the University of Minnesota and ...

A framework for the mind-matter problem in a holistic universe which has no parts is outlined. The conceptual structure of modern quantum theory suggests to use complementary Boolean descriptions as elements for a more comprehensive non-Boolean description of a world without an a priori mind-matter distinction. Such a description in terms of a locally Boolean but globally non-Boolean structure makes allowance for the fact that Boolean descriptions play a privileged role in science. If we accept the (...) insight that there are no ultimate building blocks, the existence of holistic correlations between contextually chosen parts is a natural consequence. The main problem of a genuinely non-Boolean description is to find an appropriate partition of the universe of discourse. If we adopt the idea that all fundamental laws of physics are invariant under time translations, then we can consider a partition of the world into a tenseless and a tensed domain.In the sense of a regulative principle, the material domain is defined as the tenseless domain with its homogeneous time. The tensed domain contains the mental domain with a tensed time characterized by a privileged position, the Now. Since this partition refers to two complementary descriptions which are not given a priori we have to expect correlations between these two domains. In physics it corresponds to Newton 's separation of universal laws of nature and contingent initial conditions Both descriptions have a non-Boolean structure and can be encompassed into a single non-Boolean description. Tensed and tenseless time can be synchronized by holistic correlations. (shrink)

The studies collected here are united both by a common methodology of probative investigation and by their common purpose of providing instructive insight into a varied spectrum of important philosophical issues.