Guided by a fervent strain of idealism, Gregers endeavors to reveal the truth to Hjalmar, and thereby free him from the mendacity which surrounds him. To that end, Gregers takes up residence in the Ekdal Home.
He meddles in the affairs of a strange family, producing disastrous results. Figuratively speaking, he lives in a house whose closets are full of skeletons. Over the course of the play the many secrets that lie behind the Ekdals' apparently happy home are revealed to Gregers, who insists on pursuing the absolute truth, or the "Summons of the Ideal". This family has achieved a tolerable modus vivendi by ignoring the skeletons (among the secrets: Gregers' father may have impregnated his servant Gina then married her off to Hjalmar to legitimize the child, and Hjalmar's father has been disgraced and imprisoned for a crime the elder Werle committed.) and by permitting each member to live in a dreamworld of his own—the feckless father believing himself to be a great inventor, the grandfather dwelling on the past when he was a mighty sportsman, and little Hedvig, the child, centering her emotional life around an attic where a wounded wild duck leads a crippled existence in a make-believe forest.
To the idealist all this appears intolerable. To him as to other admirers of Ibsen it must seem that the whole family is leading a life "based on a lie"; all sorts of evils are "growing in the dark". The remedy is obviously to face facts, to speak frankly, to let in the light. However, in this play the revelation of the truth is not a happy event because it rips up the foundation of the Ekdal family. When the skeletons are brought out of the closet, the whole dreamworld collapses; the weak husband thinks it is his duty to leave his wife, and the little girl, after trying to sacrifice her precious duck, shoots herself with the same gun (overhearing the fatal words from Hjalmar: "Would she lay down her life for me?"). One of the famous quotes from the doctor Relling who built up and maintained the lies the family is founded on is "Deprive the average human being of his life-lie, and you rob him of his happiness." "
Different translations use different words for the "life-lie". In Eva le Gallienne's translation, Relling says "I try to discover the Basic Lie – the pet illusion – that makes life possible; and then I foster it." He also says "No, no; that's what I said: the Basic Lie that makes life possible."
On a symbolical level, Gregers and Relling seem to be opposites (the virtue of truth against the "basic lie"). The two seem to have confronted each other at several cross-roads, and the play ends with an exchange, almost a wager between the two over the possibilities of Hjalmar and his future. In this respect, Relling is a cynic who is not able to think Hjalmar will ever change, while Gregers still thinks there is hope for his eventual "redemption".
Before the play starts, Gregers worked on a plant in the mountains, and is accused by Relling (present there as well), of "intriguing" with the local serfs (actually commons). Thus, there is a social criticism in the play, where Gregers is trying to get in touch with common men, whilst his father is mingling with high society figures – a setting in which his friend Hjalmar Ekdal is a stranger, and his father, disgraced by old Werle, is ignored by his son amongst his betters. From a social rather than a symbolic point of view, Gregers is trying to root out an unhealthy system, arguing that "truth shall set you free". In that respect, Relling, plotting with old Werle, is an advocat for the same system, and initially the opposite of Gregers (who, like Hamlet, is trying to get the truth out).
One could argue that Gregers would feel responsible for the Ekdal family and their plight, as this is an apparent consequence of his father`s manipulations and schemes. Early on, he mentions that his mother obviously died from neglect, or was driven into alcoholism by her husband´s actions. As old Werle points out: "you see me with the eyes of your mother". In this respect, the Ekdal family are helpless victims, and so is Hedvig.