It is impossible to perceive anything directly. What we experience as a visual image starts out as electromagnetic radiation of various frequencies which reflects off of an object and then hits our eye. The photoreceptor cells in our eye are stimulated, information propagates down the optic nerve, and so forth. We usually interpret this as seeing the object we are looking at. However, a more complete description involves acknowledging that we live in a simulation constructed by our brain. Our eyes, photoreceptor cells, and optic nerve are part of the interface between this simulation and physical reality. We cannot perceive an object directly, or even the light reflecting off of it. What we perceive is a representation of that object, and our brain has constructed this representation. So the reality that our brain creates has a certain correspondence to physical reality, but is not the same thing as physical reality.
Thinking along these lines, each of us can divide all things that exist or seem to exist into a few categories:
- Those things that exist in physical reality that also have a representation in my simulation. An example of this would be some particular car that I see on the street. There are atoms (or quantum wave functions at least) in the universe that correspond to this car, and there is a visual experience in my simulation that represents this car. After I look at this car and walk away, my simulation continues to have the concept of this car, at least until I have forgotten about it. So the car exists in my simulation, but it also exists in physical reality as a bunch of atoms (though there is no dividing line in physical reality between where the car atoms end and not-car atoms begin, that dividing line too is a property of the simulation). Color is another thing in our simulation that corresponds to physical reality, but is of course only a representation of it. There is no “redness” in space, redness is something that we experience. What there is in space is electromagnetic radiation, some of which produces an experience of redness in our simulations after it hits the simulation/reality interface that we call our eyes.
- Those things that exist in physical reality but have no representation in my simulation. This would include a particular planet in another galaxy that I’ve never heard of. Although I have the concept of planets existing, this particular planet has no representation in my simulation of reality.
- Those things that exist in our simulation but are not representations of specific things in physical reality. An example of this would be a hallucination (sure, there are bunnies in physical reality, but that particular bunny that you think is laughing at you now and doing head stands doesn’t actually correspond to any set of atoms). Perhaps a more interesting example from this category though would be impurity. A dish is unclean, Jewish custom says, if it has touched both milk and meat. This contamination property continues to hold even after the plate is scrubbed completely clean, even if every atom of milk and meat are removed. Suppose that a man who lives by this system of thought is given a plate, and then he is told that it was recently used to eat both meat and milk. Regardless of whether that claim is true, so long as he believes it the plate will suddenly gain the property of uncleanness in his simulation. He may experience the sense of this uncleanness quite strongly, and the thought of eating from that plate may even cause him to feel disgust.
One thing that is odd about living inside a simulation (as we each are), is that aspects of the simulation that don’t correspond to anything in physical reality can feel just as real as those that do correspond. For instance, someone I know once had a schizophrenic period where they became convinced that certain objects in their kitchen were, in fact, quite evil. This evilness was completely convincing and quite overwhelming. But what does it mean for an object to be evil? Evilness surely is not a property of atoms, quantum wave functions, or physical objects, but a property of representations of things inside our simulations. Normally we only associate this property with intelligent beings, but when the simulation goes haywire it can get associated with inanimate things. Just as we think some particular clown nose is red (i.e. our simulation contains the experience of redness which our brain links to its concept of that clown nose), we could end up thinking that some particular bar of soap is evil (i.e. our simulation contains the experience of evilness which our brain links to its concept of that soap).
Influences: Michael Vassar