Perceptual constancy, often defined as the perception of stable features under changing conditions, goes hand in hand with variation in how things look. A white wall in the orange afternoon sun still looks white, though its whiteness looks different compared with the same wall in the noon sun. Historically, this variation has often been explained in terms of our experience of “merely sensory” or subjective properties – an approach at odds with the fact that the variation does track objective features of the perceptual situation, such as illumination (in the case of colour constancy). One approach, becoming more common, is to account for the variation in terms of further “dimensions” to perceptual experience. Especially in colour perception, this is a natural thought to have but the idea is often left vague. In this paper I argue that the “dimensional” strategy has problems of its own, but is useful in drawing out some interesting complications in the way perceptual experience is structured. Specifically, the structure of “constancy spaces” brings out the different ways in which there is stability and instability in the experience of constancy, without the need for novel or merely subjective features. Instability arises in a contingent structural feature of perceptual experience.

感知恒常性，通常定义为在不断变化的条件下对稳定特征的感知，与事物外观的变化密切相关。在橙色的午后阳光下，一堵白墙仍然看起来是白色的，尽管它的白度与正午阳光下的同一堵墙相比看起来有所不同。从历史上看，这种变化经常被解释为我们“仅仅是感觉”或主观属性的经验——这种方法与变化确实跟踪感知情况的客观特征的事实不一致，例如照明（在颜色的情况下）恒常性）。一种越来越普遍的方法是考虑到感知体验的进一步“维度”的变化。尤其是在色彩感知方面，这是一个很自然的想法，但这个想法往往很模糊。在本文中，我认为“维度”策略有其自身的问题，但有助于在感知体验的结构方式中找出一些有趣的复杂性。具体来说，“恒常空间”的结构带来了恒常体验中存在稳定性和不稳定性的不同方式，而不需要新颖或仅仅是主观的特征。不稳定性出现在知觉经验的偶然结构特征中。