Lord Warburton, the blossom of the British Empire, the culmination of English manhood, the fruit of enlightened aristocracy – Lord Warburton is just a great guy. Really, he is… despite his many, many accomplishments and advantages in life, he comes off as a kind of super-average Joe. We’re not sure how he came about, or how he ended up such a totally decent bloke, but we’re certainly glad he did.
However, we’re not particularly sad that Isabel didn’t marry him – though it would have been the "smart" thing to do, in a social sense. He would have offered her security, a kind of financial and social freedom she’d never even dreamt of, and true admiration and love (at least on his part), but we get the feeling that he’s just not enough of a challenge for Isabel. Unfortunately, Osmond is too much of a challenge for her, or for anyone.
Lord Warburton’s troubles are simply that he has too much, is liked too much, and actually has a conscience. Politically, this makes him something of a rabble-rouser, while, personally, it makes him a great companion – perhaps too good of a companion. Isabel wants someone who will make her confront herself and, as she is so fond of saying, affront her so-called destiny – and that person is not Lord Warburton. She is the only thing in the world that he wants but can’t have, and it ultimately ruins his faith in true love.