I had a feeling once about Mathematics, that I saw it all-Depth beyond depth was revealed to me-the Byss and the Abyss. I saw, as one might see the transit of Venus-or even the Lord Mayor's Show, a quantity passing through infinity and changing its sign from plus to minus. I saw exactly how it happened and why the tergiversation was inevitable: and how the one step involved all the others. It was like politics. But it was after dinner and I let it go!