I think that of all of the pseudo philosophical conversations that I have had over the years my favorite one have been ones discussing the possibilities of the matrix, universe simulator, or brain-in-a-jar theories. They aren’t a very serious area of philosophical debate, primarily because when you consider all the facts it becomes apparent that if the world is an illusion of some kind then it is a completely thorough one, and that we might as well move on to areas that can be proven or disproven. I would argue that his is a prime example in favor for moving on from all such nature-of-the-universe theories, but that is a conversation for another time.
The big issue with trying to debate whether we are all really here or if we are actually rats plugged in to a machine that makes us all believe we are human being and not subjects in a simulation, is that when we look at the world around us we see no seems and that would suggest a simulation so complete that even if we had some power of perception that could pierce the veil of our physical universe, we would still see the continuity of things. That is to say, we can’t empirically test the realness of our world because any test that we could possibly devise must by definition exist in the simulation and can therefore only be measured against itself. The only hope we could possibly have is if we could get some sort of control sample, a bit of the ‘real’ world to compare to, and what would that even look like? Would we be able to identify it for what it is if we actually found one, or would we think it some kind of artificial particle, maybe even a virtual particle, which I realize is a term already used by physicists but let me clarify that I am not using the term in the same capacity.
In the end the problem is one that is impossible to resolve using the only other tool available to us, outside of experimental testing, logic. In fact using logic tends to result in the overwhelming conclusion that we must be a simulation of some kind and that in all likelihood we are part of a continuum of simulations one nesting inside of the other. But even when you apply this logic, it cannot be ruled out that we are possibly the original world and that we will start the chain with us. This is the case because even in the face of pure logic the fact still remains that there is now way of standing outside of our universe and looking in.
That being said, I do still enjoy a good concocting of some strange version of the simulation theory. The Matrix is probably the most popular of these theories. We are all heaters plugged into a computer simulation of the real world designed and run by an artificial intelligence that has finally beaten us in a war for dominance over the earth. Not bad, and it has the added bonus of being dramatic enough to set a movie to it. One older theory that runs along the same lines is that of Plato’s Wall, which I go into greater detail here, it is an interesting version because it predates any such language that we have today dealing with virtual reality and computers.
You could can imagine that the first time that it was put forward as a human brain in a vat being run by a computer, was written after the brains physiology was better understood and also after computers were invented. The theory was first phrased in the terms of “a brain in a vat” by Hilary Putnam in 1981 in his book Reason, Truth, and History. He said, what is now at the heart of the theory, that since the human brain experiences the world as a series of electrical and chemical signals it would be trivial to simulate an artificial world, as long as you could get around the two problems of keeping the brain alive and having the processing power to make the experience feel real.
I’d go a step further, and say the you don’t even need that significant amount of processing power and that is because, our brain doesn’t just experience the world as a series of electrical and chemical signals, it also actively creates at least a portion of it, internally. We find example all over, that the brain does a lot more editing of what we see and remember than anyone cares to admit. What this suggests to me is that, if a simulation even began to approach a level complexity the match what we see and hear, our brains would fill in the blanks and let us keep on going, this, in my opinion, does a fair job of explaining some of the strange inconsistencies that we see when people try to recall the same experience but have different recollections. Oops! Look at that, I just slipped right into making one of these theories without even meaning to. These types of theories are surprisingly tempting to come up with, and if you have a head for tying up loose ends, surprisingly easy too.
The really cool ones also have a malevolent force running the show, but then you start to get into the territory of conspiracy theorists and leave the realm of philosophical debate. There is one example I can think of where the author thought of a very unique take on the basic premise. The piece is called The Egg and instead of the force being malevolent, it was nurturing, and instead of aliens or robots, it was a supernatural being. I highly recommend you give it a read, and if you really don’t have the patience watch the video, they are both fairly short and with have you over scrutinizing the world, just like all such theories.
As I said before these sorts of discussions don’t even really lead to any kind of significant moments of realization, but they do stimulate thought and reflection, and that is always good for the mind. They are also just fun to try and poke holes in, and even more fun to try and repair the holes.
And that’s my take on brain-in-a-vat theories.