Silverbridge listened in silence and with something of admiration in his heart.  But he felt the strong necessity of declaring his own convictions on the special point here, at once, in this new crisis of the conversation.  That accident in regard to the colour of the Dean’s lodge had stood in the way of his logical studies,—­ so that he was unable to put his argument into proper shape; but there belonged to him a certain natural astuteness which told him that he must put his rejoinder at this particular point.  ’I think I am bound in honour and in duty to marry Miss Boncassen,’ he said.  ’And if I understand what you mean, by nobility just as much.’

‘Because you have promised.’

’Not only for that.  I have promised and therefore I am bound.  She has;—­well, she has said that she loves me, and therefore of course I am bound.  But it not only that.’

‘What do you mean?’

’I suppose a man ought to marry the woman he loves;—­if he can get her.’

’No; no; no; not always so.  Do you think that love is a passion that cannot be withstood?’

’But here we are of one mind, sir.  When I say how you seemed to take to her—­’

’Take to her!  Can I not interest myself in human beings without wishing to make them flesh of my flesh, bone of my bone?  What am I to think of you?  It was but the other day that all that you are now telling me of Miss Boncassen, you were telling me of Lady Mabel Grex.’  Here poor Silverbridge bit his lips and shook his head, and looked down upon the ground.  This was the weak part of his case.  He could not tell his father the whole story about Mabel,—­that she had coyed his love, so that he had been justified in thinking himself free from any claim in that direction when he had encountered the infinitely sweeter charms of Isabel Boncassen.  ‘You are as weak as water,’ said the unhappy father.

‘I am not weak in this.’

‘Did you not say exactly the same about Lady Mabel?’

There was a pause, so that he was driven to reply.  ’I found her as I thought indifferent, and then,—–­I changed my mind.’

’Indifferent!  What does she think about it now?  Does she know of this?  How does it stand between you two at the present moment?’

‘She knows that I am engaged to—­Miss Boncassen.’

‘Does she approve of it?’

‘Why should I ask her?  I have not asked her.’

’Then why did you tell her?  She could not but have spoken her mind when you told her.  There must have been much between you when she was talked of.’

The unfortunate young man was obliged to take some time before he could answer this appeal.  He had to own that his father had some justice on his side, but at the same time he could reveal nothing of Mabel’s secret.  ’I told her because we were friends.  I did not ask her approval; but she did not disapprove.  She thought that your son should not marry an American girl without a family.’