We have an odd relationship with words. We learn a few when we are small, throughout our lives we collect others through education, conversation, our contact with books, and yet, in comparison, there are only a tiny number about whose meaning, sense, and denotation we would have absolutely no doubts, if one day, we were to ask ourselves seriously what they meant. Thus we affirm and deny, thus we convince and are convinced, thus we argue, deduce, and conclude, wandering fearlessly over the surface of concepts about which we only have the vaguest of ideas, and, despite the false air of confidence that we generally affect as we feel our way along the road in verbal darkness, we manage, more or less, to understand each other and even, sometimes, to find each other.