The seminal idea in the book is the rejection of two of the prominent ideas in the philosophy and psychology of perception. The first is often known as the representational theory of perception. This is, very roughly, the idea that perception is the process of giving mental representations corresponding to properties and objects in the world. The second is the (related) view that perception is the process of representing a three-dimensional world as a two-dimensional visual field on the retinal image. As an alternative, Gibson argues that perception is both direct and a form of action.
From a philosophical perspective, Gibson’s view is radical since it turns the traditional picture of perception on its head. Instead of searching for, like Kant and many after him, necessary and sufficient conditions for perception to represent the world, Gibson starts by describing the actual possibilities that perceivers have and the opportunities offered by the environment. This is the ecological aspect of his theory; i.e. a detailed description of the properties of our surroundings, and the role they play for our perception of them and interaction with them.
Gibson’s work is now commonly regarded as an early defense of a so-called embodied account of perception, based on two fundamental and related insights. One is that much object-perception consists in detecting possibilities for action, which Gibson calls affordances (ch. 8). Different things afford different possibilities for action to different organisms; for example, the surface of a lake affords different possibilities for spatial navigation to insects, birds and mammals. The second is the fact that much of visual perception consist of an agent’s movements, that enable her to extract and manipulate information lying in the optic array. In this view, perception is a form of embodied active engagement with the world.
The theory of affordances is of particular interest to the NaChiLit research group. It presents the view that there is a fit between properties in our environment and our biological preconditions that makes nature available to us in a direct way. For example, we directly perceive features in nature as beneficial when they offer shelter; or as harmful, when we stand atop of a cliff. Moreover, the emphasis on perception as embodied and active brings to the fore the role being in nature, moving around in it and experiencing it with a multitude of sense modalities. Thus, it highlights the contrast between experiencing nature by affordances and other ways of experiencing nature, like those mediated by pictures or literature.
However, Gibson’s development of the idea of affordances gives rise to some questions. First, the theory is quite radical in suggesting that we directly perceive meaning and value in the world. We do not impose this on the world, since affordances themselves can be either beneficial or harmful. This idea is controversial and is related to his views on human and animal perception. Gibson’s description of properties and events in our landscape in chapters 1-3 are all from a human perspective; for example, water is swimmable for humans but this is not the case for all other animals. What he calls the ecological laws of surfaces varies from creature to creature, however, and affordances are only affordances for a given animal (p.134). This raises the question of the extent to which affordances are meaningful for non-linguistic animals.
Finally, this short review has omitted important parts of the book, such as Gibson’s detailed discussion of ecological optics in chapters 4-7 and his ideas related to picture perception in chapters 15-16.
Gunnar Karlsen, 29.09.2016