Causality and Perception

Causality and Perception

The causal theory of perception states that it is necessary condition of perceiving an object that the object causes the perception of it. The theory is very plausible, given the counterexamples to a theory without such a causal condition. If the object is causally cut off from the sense impression, we get only veridical hallucination not genuine perception—you don’t see the object. But there remains a nagging feeling that the causal theory isn’t quite right; it needs amendment. Let’s consider seeing a clock: the idea is that you can see the clock only if acts causally on your sense organs; if it doesn’t, you can’t. The clock must causally explain your visual impression. But is it true that the clock is the cause—isn’t it the surface of the clock that causes the impression? It reflects light into your eyes not the whole damn clock. And isn’t it really the atomic constituents of the surface that do the causal work not the clock as a whole? Causality is more localized in the clock than comprising the entire clock—yet you see the clock. Suppose the clock is yellow and you see it this way: does the color cause your impression? But colors don’t cause anything, being causally impotent. The physical properties of the surface do the causing: but you see the color. The color doesn’t have to cause the seeing in order to be seen. What about the space surrounding the clock—does it cause you to see it? But space doesn’t cause anything, yet you see space. What if causation is a myth, as has been held? What if there is no causation in the world? Does that mean you don’t (can’t) see anything? Hardly. What if God sets up a pre-established harmony with no causal linkages? Would that render you unable to see anything? That sounds wrong. Causality thus doesn’t seem like a conceptually necessary condition of seeing, merely what happens most of the time in the actual world. We see material objects, but only in a loose sense do we say that they cause sense impressions. Does the Sun cause you to see it? Isn’t it really the light rays emitted by the Sun that cause you to see the Sun? They are what make contact with your eyes, not the Sun itself—it is 93 million miles away. It isn’t really a necessary truth that perception depends on causation between object perceived and percept. We know we can apprehend objects that lack causal powers, such as propositions and numbers; and is it necessary for introspection that the introspected state causes the act of introspection? The concept of seeing isn’t causal. And what kind of causation do we mean? Must it be mechanical causation? But not all causation is mechanical. Could gravity act as the means of perception? If the force of gravity elicited a visual impression, would that act as the needed necessary condition? As far as I know, no such thing ever happens; but is it at least a conceptual possibility? The standard causal theory begins to seem parochial and obscure, not a self-evident conceptual truth. If you had no concept of causation, would you have no concept of perception? If you reject the former, do you thereby reject the latter? Add to this the fact that no one has been able to convert the causal necessary condition into a sufficient condition, so that no causal analysis of the concept of seeing has proved feasible. The concept of seeing is not inherently a causal concept, unlike say the concept of killing or torturing (causing to die, causing extreme pain). What kind of concept it is, is another question, to which I have no answer.[1]

[1] One might attempt a counterfactual analysis to this effect: for an impression to be a case of seeing it is necessary that if the object were not there the impression (probably) wouldn’t be either. But this is pretty pathetic stuff. What about the idea that perception has a demonstrative element, which doesn’t require a causal connection, as in “that clock”?