Do We Perceive Things or Perceptions?

When it comes to seeing objects, we can think about it two ways. 

1. We perceive what are called sense-data, that is, perceptions, and then infer things "out there" from mental images "in here."

2. We perceive objects "out there," full stop.

No. 1 runs afoul of Occam's Razor as well as the way we experience seeing things. No one in their everyday life thinks they perceive perceptions. They know they perceive things. Children begin to do this almost immediately. That later on we learn that perception (like everything else) has a specific nature involving light, eyes, brains, etc. changes nothing whatsoever. Why would anyone expect a process to have no nature? That would make no sense. Only an impossible god would see without a way to see.

No. 1 also introduces serious problems, which have long been pointed out. If all we perceive directly is something inside our heads, how do we know that this stuff corresponds to anything "out there"? Or how do we know that the "correspondence" isn't relative to persons, cultures, "races," etc.? Indeed, how can we be sure there is anything "out there"? In other words, the sense-data position leads to relativism and ultimately solipsism and skepticism--the view that we can know nothing--which is self-contradictory. These problems are creatures of model No. 1 and do not arise with model No. 2.

The relation to the God question is this: some people, Descartes famously, resort to God to escape the sticky wicket identified above. We can trust in the correspondence, it is said, because a good God would not fool us. But  that's obvious question-begging. How do you know God is good or that God is anything at all?

That we have eyes  (paraphrasing Ayn Rand) cannot be the premise of an argument that we cannot see the world "as it is." The world is what it is. Neither can the premise that we sometimes make mistakes in perceptual judgments, for example, by taking a very good model of cat in a window for a real cat. Logically, to use the concept mistake properly one must be able to use the concept correctness. We couldn't be mistaken all the time. We correct mistakes in perceptual judgments using the same organs of perception we started with. It's not usually a problem, certainly nothing to suggest that we are not in direct touch with the world.

For more, see J. L. Austin's Sense and Sensibilia.