Over the last few months, I have spent a great deal of time reading blogposts and comments on skeptical sites on the Internet, and one important fact has become readily apparent: that many in our community aren't aware of one of the most important things a skeptic should know.
I’ve seen opinions stated without any factual substantiation. I’ve seen self-styled “experts” make derisive comments about others' lack of knowledge about a topic, only to find out that it was they who were, in fact, ill-informed. Why? Because too many of us don't know what we don't know.
Skepticism should start with ourselves. When it does, we come to understand the limits of our own knowledge. Without this self-awareness, we can make fools of ourselves by stating opinions which are in direct opposition to the facts.
Before we open our mouths, perhaps, we should consider the possibility that we may not know as much about what we are going to say as we think we do. While it's no guarantee that we won't make mistakes, awareness of the limits of our own knowledge is important. Not only because it helps us avoid making fools of ourselves, but also because it spurs us to pursue that knowledge we lack, rather than closing our minds.
The most important thing to know is what you don't know.
(Of course, if you do happen to forget this, and make a fool of yourself, you can always apologize.)