Philosophy is like one who stumbles upon the end of a journey, but then has to go back into the woods to find the others who are lost. You could never be credited with your finding without showing the others. Our final product, one wants to say, is one that backtracks. I do not think this is true with mathematics. Mathematics can take its people along the venture together, as if in the same craft. What we do is much more socially laborious. It requires "show-and-tell."