I had a wild idea of stopping at Holyhead, and not going on to London that day, but I soon saw that that would be plumb foolishness.
I realized it would have been foolish for me to not go all the way to London.
mnli hypothesis: I realized it would have been foolish for me to not go all the way to London. premise: I had a wild idea of stopping at Holyhead, and not going on to London that day, but I soon saw that that would be plumb foolishness.