The concept of emergence appears in various places within the literature on expertise and expert practice. Here, I examine some of these applications of emergence in the light of two prominent accounts of emergence from the philosophy of science and philosophy of mind. I evaluate these accounts with respect to several specific contexts in which emergence seems to be an appropriate way of characterizing expertise in groups. While it is sometimes assumed that emergent phenomena are in some way inexplicable, the (...) two accounts of emergence I discuss highlight ways in which the concept of emergence relates to specific styles of explanation. (shrink)

This paper argues that a common form of representationalism has trouble accommodating empirical findings about visual space perception. Vision science tells us that the visual system systematically gives rise to different experiences of the same spatial property. This, combined with a naturalistic account of content, suggests that the same spatial property can have different veridical looks. I use this to argue that a common form of representationalism about spatial experience must be rejected. I conclude by considering alternatives to this view.

Physicalism, if it is to be a significant thesis, should differentiate itself from key metaphysical contenders which endorse the existence of platonic entities, emergent properties, Cartesian souls, angels, and God. Physicalism can never be true in worlds where things of these kinds exist. David Papineau, David Spurrett, and Barbara Montero have recently developed and defended two influential conceptions of physicalism. One is derived from a conception of the physical as the non-mentally-and-non-biologically identifiable. The other is derived from a conception of (...) the physical as the non-sui-generis-mental. The paper looks at the resources available to those conceptions, but argues that each is insufficient to yield a conception of physicalism that differentiates it from key anti-physicalist positions. According to these conceptions, if we lived in a world full of things that clearly cannot be physical, we would still live in a physical world. Thus, such conceptions of physicalism are of little theoretical interest. (shrink)

The many-faced relationship between chemistry and physics is one of the most discussed topics in the philosophy of chemistry. In his recent book Reducing Chemistry to Physics. Limits, Models, Consequences, Hinne Hettema conceives this relationship as a reduction link, and devotes his work to defend this position on the basis of a “naturalized” concept of reduction. In the present paper I critically review three kinds of issues stemming from Hettema’s argumentation: philosophical, scientific and methodological.

Philosophical Explorations, Volume 17, Issue 2, Page 172-187, June 2014.

I assess a number of connected ideas about temporal experience that are introspectively plausible, but which I believe can be argued to be incorrect. These include the idea that temporal experiences are extended experiential processes, that they have an internal structure that in some way mirrors the structure of the apparent events they present, and the idea that time in experience is in some way represented by time itself. I explain how these ideas can be developed into more sharply defined (...) views, and then argue that these views are inconsistent with certain empirical facts about how time is represented in the brain. These facts instead support a kind of atomic view, on which temporal experiences are temporally unstructured atoms. (shrink)

A prominent objection to supervenience physicalism is that a definition of physicalism in terms of supervenience allows for physicalism to be compatible with nonphysicalist outlooks, such as certain forms of emergentism. I take as my starting point a recent defense of supervenience physicalism from this objection. According to this line of thought, the subvenient base for emergent properties cannot be said to be purely physical; rather, it is “polluted” with emergent features in virtue of necessarily giving rise to them. Thus, (...) if emergentism is true, it is false that everything supervenes on physical properties. I argue that this gives way to a new challenge for supervenience physicalism. The challenge, roughly, is to distinguish the emergentist’s “polluted” base from a physical supervenience base; that is, to give conditions under which the subvenient base is not “polluted” by supervenient properties. The problem, I argue, is that it is hard to see how this can be done without collapsing supervenience physicalism into alternative approaches to physicalism. I thus argue that if the present defense of supervenience physicalism succeeds in defending the adequacy of a supervenience-based definition of physicalism, it does so by compromising its uniqueness. (shrink)

Ever since Darwin a great deal of the conceptual history of biology may be read as a struggle between two philosophical positions: reductionism and holism. On the one hand, we have the reductionist claim that evolution has to be understood in terms of changes at the fundamental causal level of the gene. As Richard Dawkins famously put it, organisms are just ‘lumbering robots’ in the service of their genetic masters. On the other hand, there is a long holistic tradition that (...) focuses on the complexity of developmental systems, on the non-linearity of gene– environment interactions, and on multi-level selective processes to argue that the full story of biology is a bit more complicated than that. Reductionism can marshal on its behalf the spectacular successes of genetics and molecular biology throughout the 20th and 21st centuries. Holism has built on the development of entirely new disciplines and conceptual frameworks over the past few decades, including evo-devo and phenotypic plasticity. Yet, a number of biologists are still actively looking for a way out of the reductionism–holism counterposition, often mentioning the word ‘emergence’ as a way to deal with the conundrum. This paper briefly examines the philosophical history of the concept of emergence, distinguishes between epistemic and ontological accounts of it, and comments on conceptions of emergence that can actually be useful for practising evolutionary biologists. (shrink)

What entitles you to rely on information received from others? What entitles you to rely on information retrieved from your own memory? Intuitively, you are entitled simply to trust yourself, while you should monitor others for signs of untrustworthiness. This article makes a case for inverting the intuitive view, arguing that metacognitive monitoring of oneself is fundamental to the reliability of memory, while monitoring of others does not play a significant role in ensuring the reliability of testimony.

Extended Cognition (EC) hypothesizes that there are parts of the world outside the head serving as cognitive vehicles. One criticism of this controversial view is the problem of “cognitive bloat” which says that EC is too permissive and fails to provide an adequate necessary criterion for cognition. It cannot, for instance, distinguish genuine cognitive vehicles from mere supports (e.g. the Yellow Pages). In response, Andy Clark and Mark Rowlands have independently suggested that genuine cognitive vehicles are distinguished from supports in (...) that the former have been “recruited,” i.e. they are either artifacts, or, products of evolution. I argue against this proposal. There are counter examples to the claim that “Teleological” EC is either necessary or sufficient for cognition. Teleological EC conflates different types of scientific projects, and inherits content externalism’s alienation from historically impartial cognitive science. (shrink)

Modal arguments like the Knowledge Argument, the Conceivability Argument and the Inverted Spectrum Argument could be used to argue for experiential primitivism; the view that experiential truths aren’t entailed from nonexperiential truths. A way to resist these arguments is to follow Stoljar (Ignorance and imagination. Oxford University Press, Oxford, 2006) and plead ignorance of a type of experience-relevant nonexperiential truth. If we are ignorant of such a truth, we can’t imagine or conceive of the various sorts of scenarios that are (...) required to make these arguments sound. While I am sympathetic to this response, in this article I will argue that we have good reason to believe that this particular ignorance hypothesis is false. (shrink)

Jaegwon Kim has argued (Kim 2006a) that the two key issues for emergentism are to give a positive characterization of the emergence relation and to explain the possibility of downward causation. This paper proposes an account of emergence which provides new answers to these two key issues. It is argued that an appropriate emergence relation is characterized by a notion of ‘transformation’, and that the real key issue for emergentism is located elsewhere than the places Kim identifies. The paper builds (...) on Victor Caston’s important work on ancient philosophy of mind (Caston 1997, 2001), but appeals to sources he has not considered. (shrink)

A blindfolded clairvoyant walks into a room and immediately knows how it is arranged. You walk in and immediately see how it is arranged. Though both of you represent the room as being arranged in the same way, you have different experiences. Your experience doesn’t just represent that the room is arranged a certain way; it also visually presents the very items in the room that make that representation true. Call the felt aspect of your experience made salient by this (...) contrast its presentational phenomenology. Many philosophers have observed that perceptual experiences have presentational phenomenology. In this paper I explore its nature, scope, and significance. I argue that in addition to perceptual experiences, presentational phenomenology can be found in intuitive, introspective, imaginative, and recollective experiences. I also argue that presentational phenomenology is epistemologically significant: it plays a central role in explaining why the experiences that have it justify beliefs and give us knowledge. (shrink)

Many philosophers say that two or more people or thinking beings could share a single human being in a split‐personality case, if only the personalities were sufficiently independent and individually well integrated. I argue that this view is incompatible with our being material things, and conclude that there could never be two or more people in a split‐personality case. This refutes the view, almost universally held, that facts about mental unity and disunity determine how many people there are. I suggest (...) that the number of human people is simply the number of appropriately endowed human animals. (shrink)

Emergence is a notorious philosophical term of art. A variety of theorists have appropriated it for their purposes ever since George Henry Lewes gave it a philosophical sense in his 1875 Problems of Life and Mind. We might roughly characterize the shared meaning thus: emergent entities (properties or substances) ‘arise’ out of more fundamental entities and yet are ‘novel’ or ‘irreducible’ with respect to them. (For example, it is sometimes said that consciousness is an emergent property of the brain.) Each (...) of the quoted terms is slippery in its own right, and their specifications yield the varied notions of emergence that we discuss below. There has been renewed interest in emergence within discussions of the behavior of complex systems and debates over the reconcilability of mental causation, intentionality, or consciousness with physicalism. (shrink)

This paper is divided into three sections. It aims to give some resources for making possible a straightforward debate on the mind-body problem as well as some serious researches in it. Having these goals into account, the first section offers an introduction to the mind-body problem and the second section explains briefly some of the most influential answers to this problem. The third section is devoted to eliminative materialism.

Downward causation is commonly held to create problems for ontologically emergent properties. In this paper I describe two novel examples of ontologically emergent properties and show how they avoid two main problems of downward causation, the causal exclusion problem and the causal closure problem. One example involves an object whose colour does not logically supervene on the colours of its atomic parts. The other example is inspired by quantum entanglement cases but avoids controversies regarding quantum mechanics. These examples show that (...) the causal exclusion problem can be avoided, in one case by showing how it is possible to interact with an object without interacting with its atomic parts. I accept that emergence cannot be reconciled with causal closure, but argue that violations of causal closure do not entail violations of the base-level laws. Only the latter would conflict with empirical science. (shrink)

The German word Destruktion was used by Heidegger in the sense that philosophy should destroy some ontological concepts and the everyday meanings of certain words. Tradition allows the transmission of knowledge and sensations of continuity and connection with the past, but it must be critically evaluated so that it does not perpetuate certain prejudices. According to Heidegger, tradition transmits, but it also conceals. Tradition induces self-evidence and prevents us from accessing the origin of concepts. It makes us believe that we (...) do not need to return to that origin. Making tradition transparent dissolves the concealments it has provoked. Here I will apply this idea to the mental and the physical by suggesting that the mind-body problem has inherited occultations that are born in Descartes himself. As a result, what could be a new philosophical framework for the research in consciousness emerges: That as an individual cognitive being I cannot avoid splitting reality into what I am and what I am not, extending then the individual duality to a collective error transmitted culturally. (shrink)

In this article, I examine some traditional Indian conceptions of unconscious mental activity. There are concepts in the Indian philosophical tradition, notably saskāras and vāsanās, which can be taken to refer to unconscious mental states and dispositions. My discussion, which is essentially philosophical by nature, is loosely based on the English philosopher C.D. Broad's distinctions concerning the unconscious. Saskāras, which are interpreted realistically in Indian tradition, may manifest themselves as what I (and Broad) call relatively unconscious states. Evidence for this (...) interpretation can be found in discussions concerning the nature of dream state and the supernatural powers of yogis in Indian tradition. It is interesting to try to view the retributive system of karma as an absolutely unconscious system, but this is not a plausible interpretation of the Indian view of karma. (shrink)

In this paper we intend to examine whether there are examples for emergence to be found in physics. The answer depends on the concept of emergence one invokes. We distinguish two such concepts, those of Broad and Kim. We will argue that it is unlikely that there will be examples with respect to the former because it runs counter to an explanatory strategy that is both well entrenched in physical practice and to a certain degree flexible. On the other hand (...) we will argue that all those physical systems that provide an example for supervenience are at the same time examples for emergence - at least if one defines emergence the way Kim does. (shrink)

Philosophical accounts of emergence have been explicated in terms of logical relationships between statements (derivation) or static properties (function and realization). Jaegwon Kim is a modern proponent. A property is emergent if it is not explainable by (or reducible to) the properties of lower level components. This approach, I will argue, is unable to make sense of the kinds of emergence that are widespread in scientific explanations of complex systems. The standard philosophical notion of emergence posits the wrong dichotomies, confuses (...) compositional physicalism with explanatory physicalism, and is unable to represent the type of dynamic processes (self-organizing feedback) that both generate emergent properties and express downward causation. (shrink)

Using the notorious bridge law “water is H 2 O” and the relation between molecular structure and quantum mechanics as examples, I argue that it doesn’t make sense to aim for specific definition(s) of intertheoretical or interdiscourse relation(s) between chemistry and physics (reduction, supervenience, what have you). Proposed definitions of interdiscourse and part-whole relations are interesting only if they provide insight in the variegated interconnected patchwork of theories and beliefs. There is “automatically” some sort of interdiscourse relation if different discourses (...) claim to have something to say about the same situation (event, system), which is the basis of (contingent) local supervenience relations, which, proper empirically support being provided, can be upgraded to ceteris paribus bridge laws. Because of the ceteris paribus feature, and the discourse dependence of event identification, there is at best only global supervenience of the “special sciences” on the physical (and of parts of physics on other parts of physics). (shrink)

Worries about mental causation are prominent in contemporary discussions of the mind and human agency. Originally, the problem of mental causation was that of understanding how a mental substance (thought to be immaterial) could interact with a material substance, a body. Most philosophers nowadays repudiate immaterial minds, but the problem of mental causation has not gone away. Instead, focus has shifted to mental properties. How could mental properties be causally relevant to bodily behavior? How could something mental qua mental cause (...) what it does? After looking at the traditional Problem of Interaction, we survey various versions of the property-based problem and look at proposed solutions to them. (shrink)

The subject matter of this thesis is analytic ontology. Chapters II and III deal with two versions of trope theory, or moderate nominalism; these are defined as ontologies which recognise properties and relations but no (real) universals. The key notion of both theories, trope, is characterised as an abstract particular. What the abstractness amounts to differs between the two. Yet another difference is that simplicity is an essential trait of a trope according to one theory, but not according to the (...) other. Though exact similarity is said to play an important role in both theories, as it turns out, this does not seem to be the case. The ontology dealt with in chapter IV is a mixture of moderate nominalism concerning qualities and realism concerning relations. In it, quality instances (moments) and universal relations are the ultimate constituents of the universe. While relations and moments are considered to be constituents of states of affairs, which are characterised as objects of higher orders, complexes that are objects of the first order are made up of moments on their own. Among these complexes one finds the ordinary objects. Paradoxically, although relations are necessary for the existence of complex first order objects, relations are not thought to be among the contents of these objects. The main subject of chapter V is a particular version of moderate realism; it is an ontology which is realistic in its recognition of universals and moderate in its recognition of instances of these universals. Instances combine to form complex networks. A theoretically motivated claim is that although each instance has a predicational aspect as well as a universal one, it is simple in the sense of lacking internal predicative structure; though, this claim can be called into question. Keywords: analytic ontology, moderate nominalism, moderate realism, particular, universal, abstract, concrete, abstract particular, abstract universal, concrete particular, concrete universal, trope, moment, complex unity, collection, instance, unit attribute, intensional aspect, predicational aspect, continuous composite, articulated composite. (shrink)

The Gestalt principle of isomorphism reveals the primacy of subjective experience as a valid source of evidence for the information encoded neurophysiologically. This theory invalidates the abstractionist view that the neurophysiological representation can be of lower dimensionality than the percept to which it gives rise.

My primary aim in this chapter is to explain in what the traditional mind–body problem consists, what its possible solutions are, and what obstacles lie in the way of a resolution. The discussion will develop in two phases. The first phase, sections 1.2–1.4, will be concerned to get clearer about the import of our initial question as a precondition of developing an account of possible responses to it. The second phase, sections 1.5–1.6, explains how a problem arises in our attempts (...) to answer the question we have characterized, and surveys the various solutions that can be and have been offered. More specifically, sections 1.2–1.4 are concerned with how to understand the basic elements of our initial question – how we should identify the mental, on the one hand, and the physical, on the other – and with what sorts of relations between them we are concerned. Section 1.2 identifies and explains the two traditional marks of the mental, consciousness and intentionality, and discusses how they are related. Section 1.3 gives an account of how we should understand ‘physical’ in our initial question so as not to foreclose any of the traditional positions on the mind–body problem. Section 1.4 then addresses the third element in our initial question, mapping out the basic sorts of relations that may hold between mental and physical phenomena, and identifying some for special attention. Sections 1.5–1.6 are concerned with explaining the source of the difficulty in answering our initial question, and the kinds of solutions that have been offered to it. Section 1.5 explains why our initial question gives rise to a problem, and gives a precise form to the mind–body problem, which is presented as a set of four propositions, each of which, when presented independently, seems compelling, but which are jointly inconsistent. Section 1.6 classifies responses to the mind–body problem on the basis of which of the propositions in our inconsistent set they reject, and provides a brief overview of the main varieties in each category, together with some of the difficulties that arise for each. Section 1.7 is a brief conclusion about the source of our difficulties in understanding the place of mind in the natural world. (shrink)

The big news about chaos is supposed to be that the smallest of changes in a system can result in very large differences in that system's behavior. The so-called butterfly effect has become one of the most popular images of chaos. The idea is that the flapping of a butterfly's wings in Argentina could cause a tornado in Texas three weeks later. By contrast, in an identical copy of the world sans the Argentinian butterfly, no such storm would have arisen (...) in Texas. The mathematical version of this property is known as sensitive dependence. However, it turns out that sensitive dependence is somewhat old news, so some of the implications flowing from it are perhaps not such “big news” after all. Still, chaos studies have highlighted these implications in fresh ways and led to thinking about other implications as well. -/- In addition to exhibiting sensitive dependence, chaotic systems possess two other properties: they are deterministic and nonlinear (Smith 2007). This entry discusses systems exhibiting these three properties and what their philosophical implications might be for theories and theoretical understanding, confirmation, explanation, realism, determinism, free will and consciousness, and human and divine action. (shrink)

This entry concerns dualism in the philosophy of mind. The term ‘dualism’ has a variety of uses in the history of thought. In general, the idea is that, for some particular domain, there are two fundamental kinds or categories of things or principles. In theology, for example a ‘dualist’ is someone who believes that Good and Evil — or God and the Devil — are independent and more or less equal forces in the world. Dualism contrasts with monism, which is (...) the theory that there is only one fundamental kind, category of thing or principle; and, rather less commonly, with pluralism, which is the view that there are many kinds or categories. In the philosophy of mind, dualism is the theory that the mental and the physical — or mind and body or mind and brain — are, in some sense, radically different kinds of thing. Because common sense tells us that there are physical bodies, and because there is intellectual pressure towards producing a unified view of the world, one could say that materialist monism is the ‘default option’. Discussion about dualism, therefore, tends to start from the assumption of the reality of the physical world, and then to consider arguments for why the mind cannot be treated as simply part of that world. (shrink)

The received view about emergence and reduction is that they are incompatible categories. I argue in this paper that, contrary to the received view, emergence and reduction can hold together. To support this thesis, I focus attention on dynamical systems and, on the basis of a general representation theorem, I argue that, as far as these systems are concerned, the emulation relationship is sufficient for reduction (intuitively, a dynamical system DS1 emulates a second dynamical system DS2 when DS1 exactly reproduces (...) the whole dynamics of DS2). This representational view of reduction, contrary to the standard deductivist one, is compatible with the existence of structural properties of the reduced system that are not also properties of the reducing one. Therefore, under this view, by no means are reduction and emergence incompatible categories but, rather, complementary ones. (shrink)

This entry focuses on two of the more historically important monisms: existence monism and priority monism . Existence monism targets concrete objects and counts by tokens. This is the doctrine that exactly one concrete object exists. Priority monism also targets concrete objects, but counts by basic tokens. This is the doctrine that exactly one concrete object is basic, which will turn out to be the classical doctrine that the whole is prior to its parts.

After sketching the historical development of “emergence” and noting several recent problems relating to “emergent properties”, this essay proposes that properties may be either “emergent” or “mergent” and either “intrinsic” or “extrinsic”. These two distinctions define four basic types of change: stagnation, permanence, flux, and evolution. To illustrate how emergence can operate in a purely logical system, the Geometry of Logic is introduced. This new method of analyzing conceptual systems involves the mapping of logical relations onto geometrical figures, following either (...) an analytic or a synthetic pattern (or both together). Evolution is portrayed as a form of discontinuous change characterized by emergent properties that take on an intrinsic quality with respect to the object(s) or proposition(s) involved. Causal leaps, not continuous development, characterize the evolution of human life in a developing foetus, of a thought out of certain brain states, of a new idea (or insight) out of ordinary thoughts, and of a great person out of a set of historical experiences. The tendency to assume that understanding evolutionary change requires a step-by-step explanation of the historical development that led to the appearance of a certain emergent property is thereby discredited. (shrink)

The holism-reductionism debate, one of the classic subjects of study in the philosopy of science, is currently at the heart of epistemological concerns in ecology. Yet the division between holism and reductionism does not always stand out clearly in this field. In particular, almost all work in ecosystem ecology and landscape ecology presents itself as holistic and emergentist. Nonetheless, the operational approaches used rely on conventional reductionist methodology.From an emergentist epistemological perspective, a set of general 'transactional' principles inspired by the (...) work of J. Dewey and J.K. Feibleman are proposed in an effort to develop a coherent ontological and methodological semantics. (shrink)

The abductivist reply to skepticism is the view that commonsense explanations of the patterns and regularities that appear in our sensory experiences should be rationally preferred to skeptical explanations of those same patterns and regularities on the basis of explanatory considerations. In this article I critically examine Laurence BonJour’s rationalist version of the abductivist position. After explaining why BonJour’s account is more defensible than other versions of the view, I argue that the notion of probability he relies upon is deeply (...) problematic, that he incorporates an implausible double-standard concerning a priori and a posteriori justification, and that his view is vulnerable to skepticism about the a priori. I suggest that some of these problems are due to idiosyncratic commitments BonJour makes and that abductivists would be better off without them. I conclude with some suggestions about how to improve BonJour’s abductivist response to skepticism. (shrink)

In this paper I argue that neuroscience has been harmed by the widespread adoption of seriously inadequate methodologies or philosophies of science - most notably inductivism and falsificationism. I argue that neuroscience, in seeking to understand the human brain and mind, needs to follow in the footsteps of evolution.

Remembering is one of the most characteristic and most puzzling of human activities. Personal memory, in particular - the ability mentally to travel back into the past, as leading psychologist Endel Tulving puts it - often has intense emotional or moral significance: it is perhaps the most striking manifestation of the peculiar way human beings are embedded in time, and of our limited but genuine freedom from our present environment and our immediate needs. Memory has been significant in the history (...) of philosophy as much in relation to ethics and to epistemology as in theories of psyche, mind, and self. (shrink)

Because there is no agreed use of the term 'self', or characteristic features or even paradigm cases of selves, there is no idea of "the self" to figure in philosophical problems. The term leads to troubles otherwise avoidable; and because legitimate discussions under the heading of 'self' are really about other things, it is gratuitous. I propose that we stop speaking of selves.

All organised bodies are composed of parts, similar to those composing inorganic nature, and which have even themselves existed in an inorganic state; but the phenomena of life, which result from the juxtaposition of those parts in a certain manner, bear no analogy to any of the effects which would be produced by the action of the component substances considered as mere physical agents. To whatever degree we might imagine our knowledge of the properties of the several ingredients of a (...) living body to be extended and perfected, it is certain that no mere summing up of the separate actions of those elements will ever amount to the action of the living body itself. (shrink)

Ultimately we will only understand biological agency when we have developed a theory of the organization of biological processes, and science is still a long way from attaining that goal. It may be possible nonetheless to develop a list of necessary conditions for the emergence of minimal biological agency. The authors offer a model of molecular autonomous agents which meets the five minimal physical conditions that are necessary (and, we believe, conjointly sufficient) for applying agential language in biology: autocatalytic reproduction; (...) work cycles; boundaries for reproducing individuals; self-propagating work and constraint construction; and choice and action that have evolved to respond to food or poison. When combined with the arguments from preadaptation and multiple realizability, the existence of these agents is sufficient to establish ontological emergence as against what one might call Weinbergian reductionism. Minimal biological agents are emphatically not conscious agents, and accepting their existence does not commit one to any robust theory of human agency. Nor is there anything mystical, dualistic, or non-empirical about the emergence of agency in the biosphere. Hence the emergence of molecular autonomous agents, and indeed ontological emergence in general, is not a negation of or limitation on careful biological study but simply one of its implications. (shrink)

This paper explores the fundamental ideas that have motivated the idea of emergence and the movement of emergentism. The concept of reduction, which lies at the heart of the emergence idea is explicated, and it is shown how the thesis that emergent properties are irreducible gives a unified account of emergence. The paper goes on to discuss two fundamental unresolved issues for emergentism. The first is that of giving a “positive” characterization of emergence; the second is to give a coherent (...) explanation of how “downward” causation, a central component of emergentism, is able to avoid the problem of overdetermination. (shrink)

The term ‘emergence’ often causes confusion in science and philosophy, as it is used to express at least two quite different concepts. We can label these concepts _strong_ _emergence_ and _weak emergence_. Both of these concepts are important, but it is vital to keep them separate.

Here I offer a precise analysis of what it takes for a property to count as emergent. The features widely considered crucial to emergence include novelty, unpredictability, supervenience, relationality, and downward causal influence. By acknowledging each of these distinctive features, the definition provided below captures an important sense in which the whole can be more than the sum of its parts.

An innocent form of emergence—what I call "weak emergence"—is now a commonplace in a thriving interdisciplinary nexus of scientific activity—sometimes called the "sciences of complexity"—that include connectionist modelling, non-linear dynamics (popularly known as "chaos" theory), and artificial life.1 After defining it, illustrating it in two contexts, and reviewing the available evidence, I conclude that the scientific and philosophical prospects for weak emergence are bright.

Physicalism is the thesis that everything is physical, or as contemporary philosophers sometimes put it, that everything supervenes on, or is necessitated by, the physical. The thesis is usually intended as a metaphysical thesis, parallel to the thesis attributed to the ancient Greek philosopher Thales, that everything is water, or the idealism of the 18th Century philosopher Berkeley, that everything is mental. The general idea is that the nature of the actual world (i.e. the universe and everything in it) conforms (...) to a certain condition, the condition of being physical. Of course, physicalists don't deny that the world might contain many items that at first glance don't seem physical — items of a biological, or psychological, or moral, or social nature. But they insist nevertheless that at the end of the day such items are either physical or supervene on the physical. (shrink)