It is very obvious throughout the 1949 movie, The Heiress, directed by William Wyler, more so than the 1880 book, Washington Square, written by Henry James, that Morris Townsend (Montgomery Clift) is only after Catherine's (Olivia de Havilland) money. He has no desire to ever fall truly in love with her and probably never could because he is too infatuated with the amount of money she will inherit once her father (Ralph Richardson) passes. I was able to notice his tactics from the beginning and wished that I could have warned her before she became so vulnerable.
The worst thing to ever do with a man is to let oneself become vulnerable. Once this happens he is able to control or have power over one. This is exactly what happened to poor Catherine. She fell so hard for Morris' smooth lines and foolish behavior towards her, that in the end she was actually the only who was truly hurt.
Yes Morris acted hurt when she would not take him back, but he will be able to get over his pain. She, on the other hand, will not be able to. She let herself become too vulnerable and also too emotional; therefore, she will probably never be able to trust another man as long as she lives. At least with her true but damaged emotions, she will also most likely never love again.
I felt this movie had a very sad ending, in that Catherine was so disturbed and angry with what had happened to her with Morris. Although she may have gotten revenge, it still did not replace the emotions and trust that she lost. Once one has lost trust in someone or something it is virtually impossible to regain. One hopes that Catherine will someday be able to have joy in her life, but as of right now it looks like it may be a very long while.