Who is Denys Finch Hatton?

Denys is one of the men, other than her father, that Beryl truly loves. He is also someone who no woman can tie down although they try to. Karen is one of those women and in the novel it seems as if he comes as close as he can to committing to her. However he's simply incapable of giving his all to her, as many such as his friend Berkeley think, or maybe Beryl's presence keeps him from doing so.