In this article, I attacked an argument for total skepticism. "Total skepticism" is the idea that no one can know anything. The argument I attacked went like this: Since we have been wrong in the past, and we didn't know we were wrong when we were, we cannot know if we are wrong or right about anything in the present, and so we can never know anything at all.
In the article, I showed that this argument is self-refuting and contradictory, relies on question-begging and selectively-applied reasoning, and ignores the evident reality that we can and do in practice evaluate claims and come to knowable conclusions. But it should be acknowledged that the argument has a kind of apparent ring of plausibility to it. It does seem like it ought to be true. When we're wrong, we don't know we're wrong, for if we knew we were wrong, well, we wouldn't be wrong! So if I think I'm right right now, how could I possibly know if I am wrong or not? I may think I'm right, but I've thought I was right before and been wrong. It does seem like this presents a logically watertight case for the impossibility of knowledge. How could we possibly justify the idea that knowledge can truly be had? We know from the absurdity and evident falseness of the argument (as pointed out in the previous article) that there must be something wrong with the reasoning here; but where, specifically, does it go wrong?
I think this case is parallel to the famous question of how we know we are awake and not dreaming. When we're dreaming, we often don't know we're dreaming; we think we're awake (insofar as it crosses our minds to think about this one way or the other). If, in my dreaming, I sometimes think I'm awake and don't seem to be able to know I'm not, how can I know this isn't happening right now while I think I'm awake?
The answer is that there are epistemological resources available to me when I am awake that aren't (typically) available to me when I'm asleep and dreaming. When I'm awake, I have the ability to examine my own state of consciousness and its contents much more carefully and thoroughly. I can compare my current state to my dream states that I remember, and I can see that they are very different. My dream states lack the degree of detail, the ongoing, coherent narrative, the full range of conscious, critical reflection upon myself that I typically have in my waking state. Because I am aware of what my dream state is like, and how it differs from my waking state, I can determine that I am not currently dreaming but awake. But when I am dreaming, my consciousness is limited, and I am typically not capable of making these observations and comparisons, and so I don't typically find out that I am dreaming. (Perhaps some people have sometimes found themselves more fully conscious while they were dreaming and have been able to perform these observations. I have never had this experience, at least not to a great extent. I think it would be fascinating to examine my dream-state with that level of criticalness, to observe its patchy character, its lack of detail, etc., while actually in such a state.) In short, it seems at first glance to follow, but upon further examination really doesn't, that if I can't tell if I am awake or dreaming when I am dreaming I must not be able to tell if I am awake or dreaming when I am awake.
I think the same sort of realization applies to our current subject as well. When I am wrong, I am lacking some perspective, some bit of knowledge, some piece of the puzzle, that I don't realize I am lacking. But when I find out I'm wrong, what happens is that I suddenly attain that missing puzzle piece. When that happens, I can see where I went wrong and (often) which way is the right way. On the latter side of this divide, I have more information, a greater vantage point, then I did before, and so I am in a better position to see accurately what is going on. Otherwise, I couldn't even know that I was wrong before! The very idea of "I was wrong before, and I just realized that" implies that I consider my current perspective a better, more accurate perspective than my previous one. Otherwise, I would have just as much reason to say, instead, "I was right before, and now I'm wrong."
Just as with the case of dreaming and being awake, it is often the case that when I am right, I have a basis to see that I am right that I am lacking when I am wrong. I can't assess my condition accurately when I am wrong, but it doesn't follow from this--though it seems to at first glance, and from here arises the apparent plausibility of the skeptical argument--that I can't assess it accurately when I'm right either. Once we've realized this, we have unconvered the fallaciousness of the skeptical argument and can see how what we know to be true--that the skeptical argument is absurd and flies in the face of what our clear, practical experience tells us--is in fact true.
And so we can reiterate the practical conclusion of the previous article. Instead of allowing ourselves to be hoodwinked by the fallacious reasoning of skepticism, we should continue to come to conclusions on the same basis all of us (including skeptics) always have anyway--by examining the evidence and embracing the conclusions that it seems to support.