Clytaemestra's murder of Agamemnon can be seen as one of the main sins in the play. The Chorus of Argive Elders calls the act 'obscene' and since one of the functions of the Chorus is to direct the audience's sympathy and give voice to pious opinions this indicates Clytaemestra is more sinning than sinned against. However when she defends her acts after the murder to The Chorus she tells them it was she who was sinned against, as her husband Agamemnon 'slaughtered' their 'own child' Iphigenia. She suggests that The Chorus are hypocrites as they 'would not cross' Agamemnon for his murder of his daughter but they call her crime 'treacherous' and are 'stunned' by it even though she says it was 'righteous' to kill him.
Clytaemestra's justification for Agamemnon's murder suggests it was Agamemnon who was the more sinful of the two and she tells the chorus he 'slaughtered' Iphigenia despite the fact his 'pastures swarmed with... flocks' suggesting he was excessive, killing people when it was unnecessary. This was something the Ancient Greeks thought was a particularly bad sin, as they believed that people should be pious and modest. One of their maxims carved in stone at Delphi was 'nothing to excess'.
However it was out of 'necessity' that Agamemnon had to 'sacrifice' his daughter, as Artemis was so upset at the thought of all the young men who would die at Troy the 'winds blew from the Strymon' at her command so the Greeks could not sail and would only let them go in exchange for Iphigenia's 'slaughter'. Although this suggests it was Agamemnon who was 'sinned against' the Chorus of Argive Elders still call him 'sacrilegious' and an 'infidel' because the murder of Iphigenia, a 'sweet', 'innocent' girl was a sin.
Revenge for Iphigenia was not Clytaemestra's only motive for 'striking down' Agamemnon however. She had taken a lover, Aegisthus while Agamemnon had been away at 'Illium' and clearly enjoyed Argos being 'my city' and wanted to continue to 'rule' it through Aegisthus. This is a sin as it was considered very wrong especially for a woman to depose a king. Indeed in Pericles' Funeral Oration he says that the greatest woman is the one 'least talked about by men' implying women should be subservient to men and Agamemnon himself remarks that Clytaemestra's 'lust for conflict' and power is 'not womanlike'. At the beginning of The Agamemnon The Watchman comments on Clytaemestra's unwomanly 'male strength of heart' and this is constantly seen as an unnatural quality throughout this play and all of Ancient Greek culture. This suggests it was Agamemnon who was the more sinned against, and Clytaemestra the more sinning.
The Chorus back this suggestion as after...