How we cite our quotes: (Act.Line)
Quote #7
YELENA ANDREYEVNA: [taking him by the hand] You don't love her, I can see it in your eyes… She is suffering… You must understand that and … stop coming here. (3.211-13)
Yelena and Astrov are having a tender moment together even while they talk about Sonya and what Astrov's lack of feelings for her means to her. When Yelena asks him to stop coming over, ostensibly because it tortures the girl, she's actually making quite a sacrifice because she has feelings for Astrov and would like him to continue to come.
Quote #8
ASTROV: [...] But if she is suffering, then of course… (3.224-25)
Astrov agrees to go along with Yelena's proposal that they sacrifice their own potential relationship in order to spare Sonya's feelings. The "of course" at the end of the line shows that Astrov has a strong sense of ethics in certain things, like his friendship with Sonya, and is willing to sacrifice his own happiness with Yelena to protect it. Also, it's not like he can really have Yelena, anyway. We highly doubt this lady is going to ditch her hubby or have an affair with a younger dude, even if she wants to. She's way too careful about the rules for that. So maybe Astrov's sacrifice isn't so huge in the end.
Quote #9
VOYNITSKY: [...] This estate would not have been bought if I had not given up my inheritance in favour of my sister, whom I dearly loved. What's more, I worked like an ox for ten years and paid off the entire mortgage... (3.388-91)
This is incredible. Can you imagine doing what Vanya did for one of your siblings? He threw his own inheritance in with his sister's so that she would have enough to marry Serebryakov and had to take out a mortgage on top of things to pay the whole estate off. He himself paid the mortgage for the house that his sister and Serebryakov lived in. He must have had some motivation for making this sacrifice, but the payoff just wasn't there.