Alec and Angel both represent different figures in society; they are both from a fairly respectable and high class, but they symbolise different aspects of high society. Alec is the "evil" side of society, he doesn't care for anyone else's well being, not even his own mother's, he seduces Tess not because he loved her, but because of his own need. He doesn't even apologize for it until he "reforms" when he has a "calling …showed first 75 words of 1354 total…

…showed last 75 words of 1354 total…he should, and it doesn't turn out alright. On the other hand, Angel didn't put on any fake airs and graces, he acted like himself, and even when he left Tess, he came around to the fact that Tess was still the person he fell in love with. Even though it ended in tragedy, Angel was still enlightened by the relationship he had with Tess and she taught him how to forget tradition and images.