The Scottish philosopher Thomas Reid first published Essays on Active Powers of Man in 1788 while he was Professor of Philosophy at King's College, Aberdeen. The work contains a set of essays on active power, the will, principles of action, the liberty of moral agents, and morals. Reid was a key figure in the Scottish Enlightenment and one of the founders of the 'common sense' school of philosophy. In Active Powers Reid gives his fullest exploration of sensus communis as the (...) basis of all philosophical inquiry. He uses common sense realism to argue for the existence of a stable external world, the existence of other minds, and to offer a powerful challenge to versions of the Theory of Ideas advocated by Hume and Locke . This is a key work of the Scottish Enlightenment that made important contributions to fundamental debates about the basis of philosophical inquiry. (shrink)

This paper sets out a view about the explanatory role of representational content and advocates one approach to naturalising content – to giving a naturalistic account of what makes an entity a representation and in virtue of what it has the content it does. It argues for pluralism about the metaphysics of content and suggests that a good strategy is to ask the content question with respect to a variety of predictively successful information processing models in experimental psychology and cognitive (...) neuroscience; and hence that data from psychology and cognitive neuroscience should play a greater role in theorising about the nature of content. Finally, the contours of the view are illustrated by drawing out and defending a surprising consequence: that individuation of vehicles of content is partly externalist. (shrink)

Today many philosophers of mind accept that the two cortical streams of visual processing in humans can be distinguished in terms of conscious experience. The ventral stream is thought to produce representations that may become conscious, and the dorsal stream is thought to handle unconscious vision for action. Despite a vast literature on the topic of the two streams, there is currently no account of the way in which the relevant empirical evidence could fit with basic Husserlian phenomenology of vision. (...) Here I offer such an account. In this article, I show how the empirical evidence ought to be understood in a way that is informed by phenomenology. The differences in the two streams are better described as differences in spatial and temporal processing. Rather than simply “unconscious,” the dorsal stream can be better described as making a special contribution to what Husserl identified as the visual horizon. (shrink)

Do we (sometimes) perceive apples as edible? One could argue that it is just a manner of speaking to say so: we do not really see an object as edible, we see it as having certain shape, size and color and we only infer on the basis of these properties that it is. I argue that we do indeed see objects as edible, and do not just believe that they are. My argument proceeds in two steps. First, I point out (...) that Susanna Siegel's influential argument in favor of the claim that we represent sortal properties perceptually does not work. Second, I argue that we can fix this argument if we replace the sortal property in question with the property of being edible, climbable or Q-able in general. (shrink)

David Milner and Melvyn Goodale’s dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action-related “unconscious” stream and a ventral, perception-related “conscious” stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, conscious vision for perception, and (...) unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action (Bruno & Franz, 2009; Dassonville & Bala, 2004; Franz & Gegenfurtner, 2008; McIntosh & Lashley, 2008). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process (Schenk & McIntosh, 2010). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action-guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi-conservative view that the dissociation hypothesis is best understood as a tripartite division. (shrink)

What is consciousness? How does the subjective character of consciousness fit into an objective world? How can there be a science of consciousness? In this sequel to his groundbreaking and controversial The Conscious Mind, David Chalmers develops a unified framework that addresses these questions and many others. Starting with a statement of the "hard problem" of consciousness, Chalmers builds a positive framework for the science of consciousness and a nonreductive vision of the metaphysics of consciousness. He replies to many critics (...) of The Conscious Mind, and then develops a positive theory in new directions. The book includes original accounts of how we think and know about consciousness, of the unity of consciousness, and of how consciousness relates to the external world. Along the way, Chalmers develops many provocative ideas: the " consciousness meter", the Garden of Eden as a model of perceptual experience, and The Matrix as a guide to the deepest philosophical problems about consciousness and the external world. This book will be required reading for anyone interested in the problems of mind, brain, consciousness, and reality. (shrink)

The classic, influential essay in 'descriptive metaphysics' by the distinguished English philosopher.

In this paper I offer an account of the meaning of must and can within the framework of possible worlds semantics. The paper consists of two parts: the first argues for a relative concept of modality underlying modal words like must and can in natural language. I give preliminary definitions of the meaning of these words which are formulated in terms of logical consequence and compatibility, respectively. The second part discusses one kind of insufficiency in the meaning definitions given in (...) the first part, which arise from the ex falso quodlibet paradox of logical consequence. In stepwise fashion, I make an attempt to avoid most of the consequences of this paradox for the meaning definitions of must and can. (shrink)

This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)

"This is an important book, and no one interested in issues which touch on the free will will want to ignore it."--Ethics. In this stimulating and thought-provoking book, the author defends the thesis that free will is incompatible with determinism. He disputes the view that determinism is necessary for moral responsbility. Finding no good reason for accepting determinism, but believing moral responsiblity to be indubitable, he concludes that determinism should be rejected.

In what follows, I will contend that the commonsense view of ourselves as fundamental causal agents - for which some have used the term “unmoved movers" but which I think might more accurately be expressed as “not wholly moved movers” - is theoretically understandable, internally consistent, and consistent with what we have thus far come to know about the nature and workings of the natural world. In the section that follows, I try to show how the concept of ‘agent’ causation (...) can be understood as a distinct species (from ‘event’ causation) of the primitive idea, which I’ll term “causal production”, underlying realist or non-Humean conceptions of event causation. In section III, I respond to a number of contemporary objections to the theory of agent causation. Sections IV-V are devoted to showing that the theory is compatible with ordinary reasons explanations of action, which then places me in a position to respond, in the final section, to the contention that we could never know, in principle, whether the agency theory actually describes a significant portion of human activity. (shrink)

Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see, the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of (...) acting. It is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The out- side world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the gov- erning laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Sev- eral lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor adaptation, visual “filling in,” visual stability despite eye movements, change blindness, sensory substitution, and color perception. (shrink)

The primary difference between direct and inferential theories of perception concerns the location of perceptual content, the meaning of our perceptions. In inferential theories of perception, these meanings arise inside animals, based upon their interactions with the physical environment. Light, for example, bumps into receptors causing a sensation. The animal (or its brain) performs inferences on the sensation, yielding a meaningful perception. In direct theories of perception, on the other hand, meaning is in the environment, and perception does not depend (...) upon meaning- conferring inferences. Instead the animal simply gathers information from a meaning- laden environment. But if the environment contains meanings, then it cannot be merely physical. This places a heavy theoretical burden on direct theories of perception, a burden so severe that it may outweigh all the advantages to conceiving perception as. (shrink)

Perry argues that certain sorts of indexicals are 'essential', in the sense that they cannot be eliminated in favor of descriptions. This paper also introduces the influential idea that certain sorts of indexicals play a special role in thought, and have a special connection to action.

Choice is one of the central elements in the experience of free will, but it has not received a good account from either compatibilists or libertarians. This paper develops an account of choice based around three features: (i) choice is an action; (ii) choice is not determined by one's prior beliefs and desires; (iii) once the question of what to do has arisen, choice is typically both necessary and sufficient for moving to action. These features might appear to support a (...) libertarian account, but they do not. Instead it is argued that all three features can be accommodated within a compatibilist account, where choice is needed because of agents' inabilities to arrive at judgements about what is best. Choice differs though from random picking: in choosing, agents frequently (though not always) deploy abilities that enable them to make good choices. In such cases, judgements about what is best will frequently follow the choice. Finally choice is distinguished from agency, and, on the basis of the distinction, the claim that choice is an action is made good. (shrink)

Since its publication in 1959, Individuals has become a modern philosophical classic. Bold in scope and ambition, it continues to influence debates in metaphysics, philosophy of logic and language, and epistemology. Peter Strawson's most famous work, it sets out to describe nothing less than the basic subject matter of our thought. It contains Strawson's now famous argument for descriptive metaphysics and his repudiation of revisionary metaphysics, in which reality is something beyond the world of appearances. Throughout, Individuals advances some highly (...) influential and controversial ideas, such as 'non-solipsistic consciousness' and the concept of a person a 'primitive concept'. (shrink)

Action is a means of acquiring perceptual information about the environment. Turning around, for example, alters your spatial relations to surrounding objects and, hence, which of their properties you visually perceive. Moving your hand over an object’s surface enables you to feel its shape, temperature, and texture. Sniffing and walking around a room enables you to track down the source of an unpleasant smell. Active or passive movements of the body can also generate useful sources of perceptual information (Gibson 1966, (...) 1979). The pattern of optic flow in the retinal image produced by forward locomotion, for example, contains information about the direction in which you are heading, while motion parallax is a “cue” used by the visual system to estimate the relative distances of objects in your field of view. In these uncontroversial ways and others, perception is instrumentally dependent on action. According to an explanatory framework that Susan Hurley (1998) dubs the “Input-Output Picture”, the dependence of perception on action is purely instrumental: "Movement can alter sensory inputs and so result in different perceptions… changes in output are merely a means to changes in input, on which perception depends directly" (1998: 342). -/- The action-based theories of perception, reviewed in this entry, challenge the Input-Output Picture. They maintain that perception can also depend in a noninstrumental or constitutive way on action (or, more generally, on capacities for object-directed motor control). This position has taken many different forms in the history of philosophy and psychology. Most action-based theories of perception in the last 300 years, however, have looked to action in order to explain how vision, in particular, acquires either all or some of its spatial representational content. Accordingly, these are the theories on which we shall focus here. -/- We begin in Section 1 by discussing George Berkeley’s Towards a New Theory of Vision (1709), the historical locus classicus of action-based theories of perception, and one of the most influential texts on vision ever written. Berkeley argues that the basic or “proper” deliverance of vision is not an arrangement of voluminous objects in three-dimensional space, but rather a two-dimensional manifold of light and color. We then turn to a discussion of Lotze, Helmholtz, and the local sign doctrine. The “local signs” were felt cues for the mind to know what sort of spatial content to imbue visual experience with. For Lotze, these cues were “inflowing” kinaesthetic feelings that result from actually moving the eyes, while, for Helmholtz, they were “outflowing” motor commands sent to move the eyes. -/- In Section 2, we discuss sensorimotor contingency theories, which became prominent in the 20thcentury. These views maintain that an ability to predict the sensory consequences of self-initiated actions is necessary for perception. Among the motivations for this family of theories is the problem of visual direction constancy—why do objects appear to be stationary even though the locations on the retina to which they reflect light change with every eye movement?—as well as experiments on adaptation to optical rearrangement devices (ORDs) and sensory substitution. -/- Section 3 examines two other important 20th century theories. According to what we shall call the motor component theory, efference copies generated in the oculomotor system and/or proprioceptive feedback from eye-movements are used together with incoming sensory inputs to determine the spatial attributes of perceived objects. Efferent readiness theories, by contrast, look to the particular ways in which perceptual states prepare the observer to move and act in relation to the environment. The modest readiness theory, as we shall call it, claims that the way an object’s spatial attributes are represented in visual experience can be modulated by one or another form of covert action planning. The bold readiness theory argues for the stronger claim that perception just is covert readiness for action. -/- In Section 4, we move to the disposition theory, most influentially articulated by Gareth Evans (1982, 1985), but more recently defended by Rick Grush (2000, 2007). Evans’ theory is, at its core, very similar to the bold efferent readiness theory. There are some notable differences, though. Evans’ account is more finely articulated in some philosophical respects. It also does not posit a reduction of perception to behavioral dispositions, but rather posits that certain complicated relations between perceptual input and behavioral provide spatial content. Grush proposes a very specific theory that is like Evans’ in that it does not posit a reduction, but unlike Evans’ view, does not put behavioral dispositions and sensory input on an undifferentiated footing. (shrink)

In this paper we secure the explanatory value of affordances by treating them as relational properties and as inherently linked to unintentional movements and possible intentional actions. We distinguish between Basic affordances, which are related to unintentional movements, and Complex affordances, which are subjective and executively controlled by individuals. The linkage between affordances and motor intentions allows for accounting for the infinite number of affordances that any given object potentially has. Appealing to objective systematic contingencies that provide the actor with (...) information about the effects of her actions, allows for accounting for perception of affordances and for securing their explanatory value. (shrink)

Some recent studies have suggested that belief in determinism tends to undermine moral motivation: subjects who are given determinist texts to read become more likely to cheat or engage in vindictive behaviour. One possible explanation is that people are natural incompatibilists, so that convincing them of determinism undermines their belief that they are morally responsible. I suggest a different explanation, and in doing so try to shed some light on the phenomenology of free will. I contend that one aspect of (...) the phenomenology is our impression that maintaining a resolution requires effort—an impression well supported by a range of psychological data. Determinism can easily be interpreted as showing that such effort will be futile: in effect determinism is conflated with fatalism, in a way that is reminiscent of the Lazy argument used against the Stoics. If this interpretation is right, it explains how belief in determinism undermines moral motivation without needing to attribute sophisticated incompatibilist beliefs to subjects; it works by undermining subjects' self-efficacy. It also provides indirect support for the contention that this is one of the sources of the phenomenology of free will. (shrink)

Why does the world look to us as it does? As Nico Orlandi argues, it is simply because of how the world is. This answer emerges from understanding vision as situated in a structured environment, and it contrasts with the view that visual perception involves an inference.

Libertarians claim that our experience of free choice is indeterministic. They think that, when we choose, our choice feels open in a way that would require indeterminism for the experience to be accurate. This claim then functions as a step in an argument in favour of libertarianism, the view that freedom requires indeterminism and we are free. Since, all else being equal, we should take experience at face value, libertarians argue, we should endorse libertarianism. Compatibilists, who think that freedom is (...) consistent with determinism, respond to this argument in a number of ways, none of which is adequate. This paper defends a stronger compatibilist response. Compatibilists should concede, at least for argument's sake, that our experience of freedom is in a sense libertarian. Yet they should also insist that our experience is in another sense compatibilist. Thus, even if libertarian descriptions of experience are phenomenologically apt, there is still a sense in which the experience might be veridical,.. (shrink)

The aim of the present article is three-fold. First, it aims to show that perception requires action. This is most evident for some types of visual percept. Second, it aims to show that the distinction of the cortical visual processing into two streams is insufficient and leads to possible misunderstandings on the true nature of perceptual processes. Third, it aims to show that the dorsal stream is not only responsible for the unconscious control of action, but also for the conscious (...) awareness of space and action. (shrink)