Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

A controversial scientific vision predicts a time in which humans and machines will merge and create a new form of non-biological intelligence, explaining how the occurrence will solve such issues as pollution, hunger, and aging.

Recent evidence in natural and semi-natural settings has revealed a variety of left-right perceptual asymmetries among vertebrates. These include preferential use of the left or right visual hemifield during activities such as searching for food, agonistic responses, or escape from predators in animals as different as fish, amphibians, reptiles, birds, and mammals. There are obvious disadvantages in showing such directional asymmetries because relevant stimuli may be located to the animal's left or right at random; there is no a priori association (...) between the meaning of a stimulus (e.g., its being a predator or a food item) and its being located to the animal's left or right. Moreover, other organisms (e.g., predators) could exploit the predictability of behavior that arises from population-level lateral biases. It might be argued that lateralization of function enhances cognitive capacity and efficiency of the brain, thus counteracting the ecological disadvantages of lateral biases in behavior. However, such an increase in brain efficiency could be obtained by each individual being lateralized without any need to align the direction of the asymmetry in the majority of the individuals of the population. Here we argue that the alignment of the direction of behavioral asymmetries at the population level arises as an “evolutionarily stable strategy” under “social” pressures occurring when individually asymmetrical organisms must coordinate their behavior with the behavior of other asymmetrical organisms of the same or different species. Key Words: asymmetry; brain evolution; brain lateralization; development; hemispheric specialization; laterality; lateralization of behavior; social behavior; theory of games. (shrink)

The topic of personal identity has prompted some of the liveliest and most interesting debates in recent philosophy. In a fascinating new contribution to the discussion, Peter Unger presents a psychologically aimed, but physically based, account of our identity over time. While supporting the account, he explains why many influential contemporary philosophers have underrated the importance of physical continuity to our survival, casting a new light on the work of Lewis, Nagel, Nozick, Parfit, Perry, Shoemaker, and others. Deriving from his (...) discussion of our identity itself, Unger produces a novel but commonsensical theory of the relations between identity and some of our deepest concerns. In a conservative but flexible spirit, he explores the implications of his theory for questions of value and of the good life. (shrink)

What does it mean to say that this person at this time is 'the same' as that person at an earlier time? If the brain is damaged or the memory lost, how far does a person's identity continue? In this book two eminent philosophers develop very different approaches to the problem.

Hilary Putnam, who may have been the first philosopher to advance the notion that the computer is an apt model for the mind, takes a radically new view of his...

The duration of “now” is shown to be important not only for an understanding of how conscious beings sense duration, but also for the validity of the phenomenological enterprise as Husserl conceived it. If “now” is too short, experiences can not be described before they become memories, which can be considered to be transcendent rather than immanent phenomena and therefore inadmissible as phenomenological data. Evidence concerning (a) the objective duration of sensations in various sensory modalities, (b) the time necessary for (...) sensations to enter consciousness and (c) the variability in the subjective sense of time's passing under different conditions is used to conclude that the duration of “now” can actually vary under normal conditions from about 10 ms to several seconds and in extreme cases up to several hours. Thus the immanent moment can be long enough to encompass a report of the contents of consciousness, making phenomenology a viable project. A further speculation from the evidence described is that consciousness takes discrete samples of the external world, at a rate inversely proportional to the duration of the “now” moment. (shrink)

The duration of “now” is shown to be important not only for an understanding of how conscious beings sense duration, but also for the validity of the phenomenological enterprise as Husserl conceived it. If “now” is too short, experiences can not be described before they become memories, which can be considered to be transcendent rather than immanent phenomena and therefore inadmissible as phenomenological data. Evidence concerning (a) the objective duration of sensations in various sensory modalities, (b) the time necessary for (...) sensations to enter consciousness and (c) the variability in the subjective sense of time's passing under different conditions is used to conclude that the duration of “now” can actually vary under normal conditions from about 10 ms to several seconds and in extreme cases up to several hours. Thus the immanent moment can be long enough to encompass a report of the contents of consciousness, making phenomenology a viable project. A further speculation from the evidence described is that consciousness takes discrete samples of the external world, at a rate inversely proportional to the duration of the “now” moment. (shrink)

There are two main views about the nature of personal identity. I shall briehy describe these views, say without argument which I believe to be true, and then discuss the implications of this view for one of the main conceptions of rationality. This conception I shall call "C1assical Prudence." I shall argue that, on what I believe to be the true view about personal identity, Classical Prudence is indefensible.

There has been considerable optimism recently, among philosophers and neuroscientists, concerning the prospect for major discoveries about the neurophysiological basis of mind. The support for this optimism has been extremely abstract and general. I wish to present some grounds ..

The book is an extended study of the problem of consciousness. After setting up the problem, I argue that reductive explanation of consciousness is impossible , and that if one takes consciousness seriously, one has to go beyond a strict materialist framework. In the second half of the book, I move toward a positive theory of consciousness with fundamental laws linking the physical and the experiential in a systematic way. Finally, I use the ideas and arguments developed earlier to defend (...) a form of strong artificial intelligence and to analyze some problems in the foundations of quantum mechanics. (shrink)

To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the (...) door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information. (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)

Functionalism in the philosophy of mind is the doctrine that what makes something a mental state of a particular type does not depend on its internal constitution, but rather on the way it functions, or the role it plays, in the system of which it is a part. This doctrine is rooted in Aristotle's conception of the soul, and has antecedents in Hobbes's conception of the mind as a “calculating machine”, but it has become fully articulated (and popularly endorsed) only (...) in the last third of the 20th century. Though the term ‘functionalism’ is used to designate a variety of positions in a variety of other disciplines, including psychology, sociology, economics, and architecture, this entry focuses exclusively on functionalism as a philosophical thesis about the nature of mental states. (shrink)

What happens when machines become more intelligent than humans? One view is that this event will be followed by an explosion to ever-greater levels of intelligence, as each generation of machines creates more intelligent machines in turn. This intelligence explosion is now often known as the “singularity”. The basic argument here was set out by the statistician I.J. Good in his 1965 article “Speculations Concerning the First Ultraintelligent Machine”: Let an ultraintelligent machine be defined as a machine that can far (...) surpass all the intellectual activities of any man however clever. Since the design of machines is one of these intellectual activities, an ultraintelligent machine could design even better machines; there would then unquestionably be an “intelligence explosion”, and the intelligence of man would be left far behind. Thus the first ultraintelligent machine is the last invention that man need ever make. The key idea is that a machine that is more intelligent than humans will be better than humans at designing machines. So it will be capable of designing a machine more intelligent than the most intelligent machine that humans can design. So if it is itself designed by humans, it will be capable of designing a machine more intelligent than itself. By similar reasoning, this next machine will also be capable of designing a machine more intelligent than itself. If every machine in turn does what it is capable of, we should expect a sequence of ever more intelligent machines. This intelligence explosion is sometimes combined with another idea, which we might call the “speed explosion”. The argument for a speed explosion starts from the familiar observation that computer processing speed doubles at regular intervals. Suppose that speed doubles every two years and will do so indefinitely. Now suppose that we have human-level artificial intelligence 1 designing new processors. Then faster processing will lead to faster designers and an ever-faster design cycle, leading to a limit point soon afterwards. The argument for a speed explosion was set out by the artificial intelligence researcher Ray Solomonoff in his 1985 article “The Time Scale of Artificial Intelligence”.1 Eliezer Yudkowsky gives a succinct version of the argument in his 1996 article “Staring at the Singularity”: “Computing speed doubles every two subjective years of work.. (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)

It is widely accepted that conscious experience has a physical basis. That is, the properties of experience (phenomenal properties, or qualia) systematically depend on physical properties according to some lawful relation. There are two key questions about this relation. The first concerns the strength of the laws: are they logically or metaphysically necessary, so that consciousness is nothing "over and above" the underlying physical process, or are they merely contingent laws like the law of gravity? This question about the strength (...) of the psychophysical link is the basis for debates over physicalism and property dualism. The second question concerns the shape of the laws: precisely how do phenomenal properties depend on physical properties? What sort of physical properties enter into the laws' antecedents, for instance; consequently, what sort of physical systems can give rise to conscious experience? It is this second question that I address in this paper. (shrink)

Personal identity deals with questions about ourselves qua people (or persons). Many of these questions are familiar ones that occur to everyone at some time: What am I? When did I begin? What will happen to me when I die? Discussions of personal identity go right back to the origins of Western philosophy, and most major figures have had something to say about it. (There is also a rich literature on personal identity in Eastern philosophy, which I am not competent (...) to discuss. Collins 1982 is a good source.). (shrink)

We define qualia space Q to be the space of all possible conscious experience. For simplicity we restrict ourselves to perceptual experience only, though other kinds of experience could also be considered. Qualia space is a highly idealized concept that unifies the perceptual experience of all possible brains. We argue that Q is a closed pointed cone in an infinite-dimensional separable real topological vector space. This quite technical structure can be explained for the most part in a simple, intuitive way. (...) The structure of qualia space allows us to consider and even answer in a precise way such questions as: Is there a continuous path from the sensation of blue to the sensation of pain? Once we fix a desired accuracy of approximation, do there exist finitely many perceptual experiences such that any possible perceptual experience is approximately equal to one of them? What should be meant by ‘fundamentally different’ perceptual experiences? There is the possibility of additional structure, such as a Hilbert space structure on the vector space in which Q is embedded. (shrink)