Online research in philosophy

The phenomenological tradition has always had a peculiar preoccupation with light. This paper will attempt to determine how and why light appears as it does, and what this can tell us about the phenomenological understanding of light and its relevance. This will be carried out through a systematic analysis covering Husserl's study of light as "circumstance of apperception," Heidegger's interpretation of Plato's use of light as "symbol for the unsayable," and Levinas' interest in light as "rival to the 'there is'." This survey will allow us to see how light has been treated by phenomenology as a concept of central importance in the realms of perception, epistemology, and ontology. It is this multiform use that has allowed for the distinction between the concepts of "light" and "lighting" to become blurred, and has thus problematized any attempt at something like a phenomenology of light.

A widely accepted theory holds that emotional experiences occur mainly in a part of the human brain called the amygdala. A different theory asserts that color sensation is located in a small subpart of the visual cortex called V4. If these theories are correct, or even approximately correct, then they are remarkable advances toward a scientific explanation of human conscious experience. Yet even understanding the claims of such theories—much less evaluating them—raises some puzzles. Conscious experience does not present itself as a brain process. Indeed experience seems entirely unlike neural activity. For example, to some people it seems that an exact physical duplicate of you could have different sensations than you do, or could have no sensations at all. If so, then how is it even possible that sensations could turn out to be brain processes?

Perceptual experience can be explained by contextualized brain dynamics. An inner loop of ongoing activity within the brain produces dynamic patterns of synchronization and de- synchronization that are necessary, but not sufficient, for visual experience. This inner loop is controlled by evolution, development, socialization, learning, task and perception- action contingencies, which constitute an outer loop. This outer loop is sufficient, but not necessary, for visual experience. Jointly, the inner and outer loop may offer sufficient and necessary conditions for the emergence of visual experience. This hypothesis has methodological, empirical, theoretical, and philosophical implications.

The theory presented here is a near neighbour of Humphrey's theory of sensations as actions. O'Regan & Noë have opened up remarkable new possibilities. But they have missed a trick by not making more of the distinction between sensation and perception; and some of their particular proposals for how we use our eyes to represent visual properties are not only implausible but would, if true, isolate vision from other sensory modalities and do little to explain the phenomenology of conscious experience in general.

Special relativity insists that the speed of light in a vacuum is constant for all inertial observers. This is often said to be counterintuitive: why should light alone, among all things in the world, return the same speed value to all inertial observers, regardless of their different states of motion? I argue that this question or puzzle arises because physics misconstrues light by characterizing it as a freestanding phenomenon. As James Gibson insisted, and as any analysis of the visual experience makes plain, light, the agency of sight, cannot be overtaken by sight. A better characterization of light is Gibson's optic array, which prompts the realization that our prior complicity with light keeps us from getting leverage on it as a freestanding phenomenon, and this is why it returns the same speed value to all observers. To show the limitation of freestanding light, I offer two derivations of relativistic time dilation. The first imagines freestanding light and then, to complete the derivation, artificially requires light speed constancy; the second achieves the same result in a fully natural way?that is, without putting observers in an abstract, arguably impossible, situation?by merely attending to the seeing experience.

Traditional theories locate color in primary qualities of objects, in dispositional properties of objects, in visual fields, or nowhere. In contrast, we argue that color is located in properties of light. More specifically, light is red iff there is a property P of the light that typically interacts with normal human perceivers to give the sensation of red. This is an error theory, because objects and visual fields that appear red are not really red, since they lack the properties that make light red. We show how this light theory solves or avoids problems that afflict its competitors.

Light is puzzling in modern physics–witness wave-particle duality, the two-slit experiment, and the invariant speed of light. These puzzles are not intrinsic to light but arise from overly narrow views of light. Disregarding the expansive, unitary nature of light that informs everyday experience, modern physics treats light as if it were self-bounded and separable. Further, physics assumes that light is not complicit with observations of light, that the two are separable. By likening light to light-illuminated entities, these attitudes set the stage for puzzles. When,however, conceptions of light are aligned with visual experience, those puzzles become occasions of understanding.This is because visual experience already embodies that aspect of light which physics finds so anomalous: nonseparability. Light's interactive vastness shows up wherever light shows up, and because no observer can back away from light or step outside its integrative embrace, different parts of light (photons) cannot be lifted out ofthe observation as distinct – i.e., distinctly-observed – entities.