Four of Ibsen’s most important plays in superb modern translations, part of the new Penguin Ibsen series.     With her assertion that she is “first and foremost a human being,” rather than a wife, mother or fragile doll, Nora Helmer sent shockwaves throughout Europe when she appeared in Henrik Ibsen’s greatest and most famous play, A Doll’s House. Ibsen’s follow-up, Ghosts, was no less radical, with its unrelenting investigation into religious hypocrisy, family secrets, and sexual double-dealing. These two masterpieces are accompanied here by The Pillars of Society and An Enemy of the People, both exploring the tensions and dark compromises at the heart of society.