You see, but you do not observe. The distinction is clear. For example, you have frequently seen the steps which lead up from the hall to this room." "Frequently." "How often?" "Well, some hundreds of times." "Then how many are there?" "How many? I don't know." "Quite so! You have not observed. And yet you have seen. That is just my point. Now, I know that there are seventeen steps, because I have both seen and observed.