UCLA

We perceive the world as organized in certain ways. While a human retina has approximately 100 million photoreceptors, one does not merely see a scene as a collection of 100 million discrete points. Rather, one sees arrangements of complexly shaped, three-dimensional, colored objects—humans, trees, and butterflies, for example. One perceives these things as having parts—limbs, boughs, and wings—each of which has its own specific shape, color, and parts. Not only does one perceive the world as organized in certain ways, one’s very perceptual states are themselves organized from parts. When you perceive a butterfly, the state you are in has as parts your states of seeing the butterfly’s color, texture, and shape. And these states may themselves have parts, though they are not easily identified through introspection. The idea that perceptual states have parts that can combine and recombine in rule-governed ways is central to much of contemporary psychology and over the last century perceptual psychologists have closely investigated the ways in which perceptual states are structured. The aim of this dissertation is to illuminate the relationship between the ways perceptual states are made up from parts (their structures) and the ways that they represent the world as being (their contents).

I first examine what it means to say that perceptual states have other perceptual states as parts. I do this by elucidating the explanatory value of attributing part-whole structure to perceptual states. I then defend the principle that perception is compositional: the content of a perceptual state depends entirely on the contents of its parts and how those parts are put together. A number of perceptual phenomena, of the sort that interested the early Gestalt psychologists, pose puzzles for the claim that perception is compositional. I show, first of all, how to account for such phenomena within a compositional framework, and, second of all, that compositional accounts of such phenomena are illuminating.

By examining the relationship between the structures of perceptual states and their contents, we can better address central questions in the philosophy of mind. I argue that the structural forms of perceptual states reflect important spatial (and perhaps other) patterns in the perceiver’s local environment. This point reveals a fundamental difference between perception and thought. I then address the distinctively perspectival character of perception—the sense in which a slanted coin has an elliptical look even as one correctly sees it as circular. I argue that attempts to explain the perspectival character of perception merely in terms of the properties that one perceives things as having are problematic. Instead, I propose that the perspectival character of perception is rooted in the ways our perceptual states are structured.

This work therefore develops a framework for understanding perception by examining the nature of the parts of perception and the ways in which those parts combine to give rise to a rich perception of the world.