Online research in philosophy

The outlines of a novel, fully naturalistic theory of perception are provided, that can explain perception of an object X by organism Z in terms of reflexive causality. On the reflexive view proposed, organism Z perceives object or property X just in case X causes Z to acquire causal dispositions reflexively directed back upon X itself. This broadly functionalist theory is potentially capable of explaining both perceptual representation and perceptual content in purely causal terms, making no use of informational concepts. However, such a reflexive, naturalistic causal theory must compete with well entrenched, supposedly equally naturalistic theories of perception that are based on some concept of information, so the paper also includes some basic logical, naturalistic and explanatory criticisms of such informational views.

One popular reason for rejecting moral realism is the lack of a plausible epistemology that explains how we come to know moral facts. Recently, a number of philosophers have insisted that it is possible to have moral knowledge in a very straightforward way—by perception. However, there is a significant objection to the possibility of moral perception: it does not seem that we could have a perceptual experience that represents a moral property, but a necessary condition for coming to know that X is F by perception is the ability to have a perceptual experience that represents something as being F . Call this the ‘Representation Objection’ to moral perception. In this paper I argue that the Representation Objection to moral perception fails. Thus I offer a limited defense of moral perception.

Questions about perception remain some of the most difficult and insoluble in both epistemology and the philosophy of mind. Perception provides a highly accessible introduction to the area, exploring the philosophical importance of those questions by re-examining the sense-datum theory, once the most popular theory of perception. Howard Robinson surveys the history of arguments for and against the sense-datum theory, from Descartes to Husserl. Robinson contends that the objections to the theory, particularly Wittgenstein's attack on privacy and those of the physicalists, have been unsuccessful. He argues for returning to the theory in order to understand perception. In doing so, he seeks to overturn a consensus that has dominated the philosophy of perception for nearly half a century.

The primary objects of hearing are sounds: everything we hear we hear by hearing a sound. (This claim differs from Berkeley’s that we hear only sounds and from Aristotle’s that we only hear sounds.) Colored regions are primary objects of sight, and pressure resistant regions are primary objects of perception by touch. By definition, the primary objects of perception are physical. The properties of the primary objects of perception are exactly the properties sense-datum theories attribute to sense-data. Indirect Realism holds that awareness of sense-data (or something similar) mediates our perception of primary objects. Direct Realism denies this. The question when the perception of a primary object, such as parts of the surfaces of a hat and coat, is thereby the perception of a non-primary object, such as a person, is independent of the disagreement between Direct and Indirect Realism.

Direct Realists believe that perception involves direct awareness of an object not dependent for its existence on the perceiver. Howard Robinson rejects this doctrine in favour of a Sense-Datum theory of perception. His argument against Direct Realism invokes the principle ‘same proximate cause, same immediate effect’. Since there are cases in which direct awareness has the same proximate cerebral cause as awareness of a sense datum, the Direct Realist is, he thinks, obliged to deny this causal principle. I suggest that although Direct Realism is in more than one respect implausible, it does not succumb to Robinson’s argument. The causal principle is true only if ‘proximate cause’ means ‘proximate sufficient cause’, and the Direct Realist need not concede that there is a sufficient cerebral cause for direct awareness of independent objects.

Seeking whether our perception produces knowledge which is not only relative or subjective perspective on things, is to be engaged in the realist/anti-realist debate regarding perception. In this article I pursue the naturalistic approach according to which the question whether perception delivers objective knowledge about the external world is inseparable from empirical investigation into mechanisms of perception. More precisely, I have focused on the dual aspect theory of perception, one of the most influential recent theories of perception which unifies two traditionally opposite approaches to perception: ecological and constructivist. I have tried to show that the dualistic model of human vision does not support the majority of realist theses aimed at non-relativism, but supports only pragmatic realism about observational reports (dorsal system) and the moderate realism about observational reports (ventral system).

A theory of perception must be capable of explaining the full range of conscious perception, including amodal perception. In amodal perception we perceive the world to contain physical features that are not directly detectable by the sensory receptors. According to the active-externalist theory of perception, amodal perception depends on active engagement with perceptual objects. This paper focuses on amodal visual perception and presents a counter-example to the idea that active-externalism can account for amodal perception. The counterexample involves the experience of so-called ‘impossible objects’, objects experienced in perceptual character as having geometrical properties that no physically real object can have.

There are currently two main philosophical theories of perception - Direct Realism and the Representative Theory. The former is supported by most contemporary philosophers, whereas the latter forms the groundwork for most scientific theories in this area. The paper describes a recent experiment involving retinal and cortical rivalry that provides strong empirical evidence that the Direct Realist theory is incorrect. There are of course a large number of related experiments on visual perception that would tend to lead us to the same conclusion, but the experiment described in this paper does so in a singularly direct and straightforward manner. Often the most telling experiments are the simplest.

Reid's theory of perception has long been cited as a paradigmatic example of direct realism; and the term “direct” undoubtedly carries the connotation that external objects are items in “the manifold of intuition.” There are important ways in which perception, on Reid's analysis, undoubtedly is immediate and direct. Nonetheless, this paper contends that, with the exception of his account of our perception of visible fi gure, Reid's theory is not an example of direct realism, if a condition of a theory of percep- tion's being a direct realist theory is that it hold that perception yields acquaintance with external objects, so that those objects are present to consciousness. The defense given in Thomas Reid and the Story of Epistemology of the no-acquaintance interpretation of Reid's theory occurred in the context of a comprehensive account of Reid's theory of perception, and was accordingly brief. This essay places that interpretation in the center of attention so as to offer a more adequate defense, developing somewhat more fully the arguments briefly presented in the book, and adding some additional considerations.