Towards a deeper clarity of not understanding.
Brief guide to what got discussed. The question "what's north of the North Pole?" makes no sense (because from the North Pole whichever way you go you will always be going South). Thinking that this question makes sense is to make a mistake. That mistake is to do with thinking that because the question of the general form "what's north of x?" makes sense that it follows from this that the question always make sense even when x = "the North Pole". ... How many other things are there that we think make sense but don't? Is this kind of mistake inherent in metaphysical and religious issues? For example is the question "what caused the First Cause?" making the same mistake made by the question "what's north of the North Pole?" ... Time travel: is thinking that you can travel back in time a nonsense? The impossibility of there being something north of the North Pole is a logical impossibility. Which is different from factual impossibility. So if, four hundred years ago, people were told about Television they would have said such a thing was impossible. They would also have said it was impossible that 7+5=32. These two kinds of impossibility are different. It's logically impossible that 7+5=32. But maybe there is no difference. It depends what you mean by adding. So one crowd plus one crowd equals one crowd. Which is to say 1+1=1. Whereas you would have thought it's a basic logical arithmetical fact that 1+1=2. Depends on your assumptions. It used to be a basic geometrical fact that the internal angles of a triangle add up to 180 degrees. But in non-Euclidean geometry this is false. It's only true if you assume things are Euclidean. ... Scientists say the universe is expanding. Do they mean space is expanding? Does that make sense? To say that something is expanding is to say that over time it's taking up more space. How can space take up more space than it used to? (I think next time we need to talk about something less metaphysical!)