1. Since I don't know who you are, dear reader, and since I know that some people don't have hands, I don't know whether you have hands. Probably you do, but knowing that something is probable is rarely, if ever, a way of knowing that thing. By contrast, I know that I have hands. Let me check. Yes, here is one of my hands; and here is another. Since I know that here is one of my hands and that here is another, and since I know that it follows from those two claims that I have hands, I can deduce that I have hands. So, I know that I have hands.