The naive realist makes several claims about perception which should be fully and clearly outlined before we go onto discuss objections to the theory.
- Objects exist independently of any perception of them.
- Perception gives us immediate and direct perceptual contact with independent material objects.
- Perceptions of these independent objects exactly resemble the
- Independent objects are the cause of our perceptual experiences.
- The perceiver contributes nothing to the perception and merely passively records the objects of perception.
With all that we know about physics and perception is the theory of naive realism, really tenable?
Problems for Naive Realism
1. Problem of Secondary Qualities and Other Scientific Problems
- Our knowledge of Newtonian and non Newtonian physics seems to tell us that material objects do not have some of the inherent properties to which common sense would attribute to them. For example we know that colors arise from the micro physical surface structure of objects. The colors we perceive are caused by how the micro physical structure of objects reflects or absorbs light. It seems that in the objective world independent of biased perceivers these qualities do not exist. It's questionable whether a distinction between Secondary and Primary Qualities makes sense, Bishop Berkeley pointed out it wasn't possible conceive of a colorless object. While A.N Whithead described the separation of Primary and Secondary Qualities as a scientific abstraction which has been falsely taken a objective truth.
- The Problem of Empty Space: according post Newtonian physics objects that appear to be solid and substantial to us, consist of mainly empty space. The positive and negative electric charges of the micro physical level are what ultimate physical reality is solely composed of. It is argued that if you accept the account of modern post Newtonian physics then Naive realism cannot possibly true. Eddington's famous two tables comment offers one of the best expositions of this: I have settled down to writing these lectures and have drawn up my chairs to my two tables. Two tables! Yes; there are duplicates of every object about me—two tables, two chairs, two pens…One of them has been familiar to me from earliest years. It is a commonplace object of that environment which I call the world…It has extension; it is comparatively permanent; it is coloured; above all it is substantial…Table No. 2 is my scientific table. It is a more recent acquaintance and I do not feel so familiar with it…My scientific table is mostly emptiness. Sparsely scattered in that emptiness are numerous electric charges rushing about with great speed; but their combined bulk amounts to less than a billionth of the bulk of the table itself…There is nothing substantial about my second table. It is nearly all empty space—space pervaded it is true by fields of force, but these are assigned to the categories of ‘influences’ not of ‘things’.
2. Relativity and Perspective
- Species relativity presents a problem for Naive realists, as the range of sensory experience varies significantly from species to species. With their being such a huge variability between various species, how can humans claim their experience represents the objective world. For example we know cows can see larger amount of the visual spectrum than we can and dogs can hear a wider range of sound frequencies.
- Human perspectives, normally we can only see a part of the surface of the object at one time, at a particular angle or in a particular light. As we only ever have sensory experience of a very limited amount of the world at any one time. This makes it seem very probable that the world can not be exactly as we experience it.
- Unique perspective of the world, each person has a distinctly unique perspective of the world, each persons perspective to the world is different we can rarely ever have the same experience of the world. There is also plenty of evidence to suggest perception varies between individuals.
3. Time Lag Argument
- Often considered the knock down argument against Naive realism. The time lag argument is another scientific argument against the naive realists view of perception. It takes eight minutes for the light from the sun to reach earth and from very distant stars it can take millions of years, by the time this light reaches earth. Many of the stars we see in the sky are dead by the time the light from them reaches us. Many people think the problem can be dissolved by taking an adverbialist approach. By describing our experience of seeing a star in the sky in a different way we can avoid the stating that we are seeing a star that has been dead for millions of year. Instead something like, 'The star appeared white-ly to me' would avoid the problem. But even with the closest objects their is a minimal time lag, which seems to harder to explain away by taking an adverbialist approach.
Other more nuanced complaints have also been made about Naive Realism, but under the criticism from these complaints alone the position of the Naive realist seems rather untenable.