One of the classes I took was on skepticism. In that class we really dove into Descarte’s notion that we could be dreaming or deceived by a “deceiver god.” We even took the idea further, that we are just a brain in a vat that some evil genius on a far away planet is tweaking to give us the ideas we have about our whole life. How do we know this isn’t happening? If we don’t know this is not happening then can we know anything about the external world?
I took this problem seriously with my oath to follow logic. I was sure I would be able to solve such a fundamental problem which threw into doubt so much of what we take for granted. But in following that oath to logic I had to admit in the end that we really have no evidence to think it is not happening.
Several very intelligent people took a stab at it. For example could we presume that because things seem coherent over and over therefore perhaps they are. Again and again I walk on a floor and don’t fall through so that means it’s solid. Sadly, that doesn’t work because the evil genius could just give us that thought that things are the way they are. Every time we walk through a wall as in a poorly programed computer game, he might just have us forget it or give us the thought that it was only a dream. He might just be tweaking the brain to force the belief that we the world is coherent even though it’s not.
Another writer basically proposed that what we perceived even if it is the product of an evil genius is actual reality. But that is just believing the shadows on the wall from Plato’s allegory of the cave is reality. There were several other attempts and failures along the way.
Some people might think wracking your brain over such issues is just a waste of time. But I strongly disagree. I did not learn that I could start walking in front of buses because maybe it was just a dream, but that does not mean I didn’t learn anything. I think I learned a lot from the experience.
1) That we live in an uncertain reality and we just need to deal with it as best we can.
2) That even science which is based on empirical evidence (perceptions) is based on assumptions that have no evidence to support them. That does not mean I am anti-science. I am not anti-science.
3) That to a certain extent we are captive to our beliefs/mind. In that we can’t really step outside our beliefs/mind to objectively examine them.
4) I also learned allot about what it means to “know” something. And in relation to this problem I realized that we don’t need to know we know something to know it.
The traditional understanding of knowledge is this:
Subject, S, knows proposition, P, if and only if:
1) P is true
2) S believes P
3) S has sufficient reason to believe p.
In later blogs we will get back to this definition, how it was refuted by a philosopher named Gettier, and how Robert Nozick tried to revitalize it. Nozick’s ideas are important for a key argument made by another philosopher on a very different and important issue. But this blog is long enough already so I will just end it with the traditional definition.