What are the sources of our beliefs? How do we know that these sources are ever reliable? Something called skepticism deals with these questions. It challenges us to justify the sources of our beliefs, including memory, testimony, and sense experience. So how do we know that those sources are ever reliable? To make things easier, I’ve decided to deal with this matter one step at a time.
To start off, let’s begin with trying to justify our belief in memory. How do we know that memory is ever reliable? One could try to justify belief in memory by saying something like, “I remember people telling me my memory is sometimes reliable.” One could also say, “I remember many times when I recall where I parked my car. When I went to the place where my memory told me I parked my car, it was there.” Yet, since those responses presuppose the reliability of memory to justify the reliability of memory, there is the logical fallacy of circular reasoning (assuming the truth of something that the argument is supposed to establish). Consequently, we have yet to provide any real evidence to support the reliability of memory.
Skepticism also challenges us to demonstrate that testimony is sometimes reliable. One could say, “Someone once told me Bob’s favorite color was blue. I went to him and he told me that was true.” This is using testimony to justify testimony, which is circular reasoning again. Another way to respond is to say something like, “I remember someone telling me that Bob’s hair was brown. I recall looking at his hair and seeing that it was brown.” That is using memory to justify testimony. Yet, we could not find any genuine evidence that memory is reliable. As a result, we still don’t have any legitimate proof that testimony is reliable either.
One could try to give reason for believing in memory and testimony by appealing to our senses. For example, if my memory tells me I put my candy bar on my desk, and I see a candy bar on the desk, then apparently there is at least some rational support that my memory is sometimes reliable. Or if someone is telling me that the sky is blue while I am looking at a clear blue sky, then there seems to be reason to believe that testimony can be reliable. Of course, skepticism applies to the realm of our senses also. So how do we know that sense experience is ever reliable? A response to that could be, “I remember when I thought I saw a milkshake. I went closer and tasted it, and my senses consistently told me it was a milkshake.” That is using memory to justify sense experience, and we couldn’t find any reason to believe that memory is ever reliable, but let’s ignore that for the moment. The statement is using sense experience to justify our belief in sense experience. That is circular reasoning yet again.
There does not seem to be a shred of untainted evidence that such sources of our beliefs are ever reliable. But on the other hand it seems irrational, even dangerous, to incessantly doubt these sorts of things. For example, I think it would be unwise of me to walk in the middle of a railroad track and simply watch a train speed towards me, all the while contemplating whether or not it’s really there. But if there is no shred of legitimate proof to support things like the reliability of memory and sense experience, how do people come to accept these sources of beliefs? What is the basic principle of belief? In a word, intuitiveness. I accept what I naturally, strongly, and intuitively believe to be true. My intuitive perceptions tell me that I exist, that I have free will, and that logic is reliable. My intuitive feelings also tell me that memory, testimony, and sense experience are sometimes reliable. This is how people accept such sources of beliefs without evidence or proof. How do I know that these intuitive feelings and perceptions are ever reliable? I can’t use this source of belief to justify itself, otherwise I would be guilty of circular reasoning. Although there isn’t any independent support for this principle, it at least passes its own test. That is, our own intuitive perceptions confirm that it’s true. Even though there isn’t any independent evidence that supports the principle, there is no independent standard of rationality that can criticize or even call into question the principle either. Logic may inform us that there is no independent support for the principle, but logic itself is an intuitive perception. One note: some intuitions are stronger than others. For example, suppose I intuitively believe that my senses are reliable, and that I also have a hunch that it’s going to be a sunny day outside tomorrow. Now suppose it turns out that it wasn’t going to be a sunny day after all. In this case, I would renounce the hunch that told me it was going to be a sunny day because my other intuitive belief is stronger. Skepticism may not be able to cause us to renounce our basic beliefs, but it is capable of giving us an amazing revelation: we can and do rationally accept beliefs without proof or evidence. That, I think, is a lesson worth learning.