You destroy men and women too every bit as wantonly, and soon, thanks to you, there will be no loyalty, integrity, or unselfishness left on earth. Why does it upset you so much to see a woman who doesn't belong to you? Because—and the doctor's right—there's a demon of selfishness in every one of you.
Undeniably, some of the most important human traits are kindness and compassion. However, while people appreciate and laud these traits, most of them don’t show and use them in the necessary situations. Humanity is more and more callous and insensible to nature, the environment, and people, all of which require help and support. Chekhov calls out this tendency in Helen's words, equating environmental destruction with the destruction of the Russian character. He subtly asks his audience/readers to be more cognizant of the way they treat nature and their fellow human beings.
Anyone who betrays a wife or husband could easily be unreliable enough to betray his country as well.
Betrayal of all sorts is an astonishingly painful experience. There are commonly shared expectations about marital fidelity and love of one's country; when those are violated, it is shocking and cruel. However, despite some similarities, Telegin's equating a marital issue with treason is outlandish and hyperbolic. This is not surprising given the nature of Telegin's character (his "a subject worthy of Ayvazovsky's brush" comes to mind): he is prone to misreading situations, falsely conflating things, and obfuscating the real issue. It's not just Telegin, though: Chekhov is setting the stage for nearly all of his characters' ludicrous melodramatic behaviors and tendentious claims.
Men may forget, but God will remember.
Marina and Sonya are similar in their religiosity, and Sonya's comments at the end of the play merely echo these of Marina's, spoken only a few moments into the play. She is the only character in the play who is truly content and doesn't mind or get caught up in the squabbling, protestations, and idle melodrama. While we may admire this steadfast religious faith, it has its limitations for other characters. Astrov, for example, isn't religious, and he is full of deeply felt complaints and frustrations about his stressful, demanding, and sometimes heart-wrenching job. Marina's words seem banal and flat: they cannot provide real solace or relief, and they point to Chekhov's own religious struggles.
Never mind, Mr. Galetin, we'll drink it cold.
In this subtly humorous moment, Helen blithely calls Telegin by the wrong name, to which he follows up with an indignant (but no doubt respectful) speech about what his real name is, how long Helen has known him, etc. In this one little phrase, much of Helen's character is summed up. She does not intend to be rude; rather, she is rude in virtue of her indifference. She is unable to engage with others because she simply doesn't care about life that much. She is bored, idle, and unhappy and does not strive to free herself from that state of mind; as a result, she can barely drum up enough feeling for others. Sonya is the only person she truly seems to care about; Telegin is simply so far from her emotional radar and capabilities that she nothing to offer him—not even remembering his name.
God alone knows what our real business in life is.
This is a perfect encapsulation of the angst and ennui that most of the characters feel, and, as Astrov is the voice of intellectual frustration, it is fitting that Chekhov gives him this line. He is talking about his medical practice vs. his forestry hobby and articulates the fact that he does not know what the purpose of life is. Is it to help others? To be happy? To help future generations? To find love? To contribute to the intellectual discourse? To honor one's country? Astrov vacillates between finding meaning in his life and feeling a sense of despair and that he has no power to bring about anything positive. This is a relatable human sentiment, one that no doubt helped to secure Chekhov's work as a new type of more realistic drama.
There's going to be a storm. Did you see that!
This is an excellent example of foreshadowing and symbolism. Vanya tells the others that there is going to be a storm outside, and he is correct: lightning, thunder, and rain soon ensue. Before the storm, everything is placid and peaceful; during the storm, things are tempestuous and chaotic; and after the storm, everything returns to normal. Vanya's outburst and attempted murder of Serebryakov figure in much the same way. Though discontented, life is mundane before Serebryakov shows up and announces he plans to sell the estate. Vanya then erupts into frenzied rage, but it is not long before he returns to his former morose self. Nothing has changed at the end of the play even though he acted as a storm of sorts, just as the estate was not harmed by the actual storm.
My time of life is neither here nor there. When people aren't really alive they live on illusions. It's better than nothing anyway.
Vanya has many ways to describe his unhappiness. Here he suggests he is unmoored, adrift in space and time. He also suggests he is not really alive, and that the only thing that sustains him are illusions: illusions of seducing Helen, of besting Serebryakov, and of doing something notable in arts and letters. His problems are not completely fabricated: certainly, his life is lacking in several ways. However, Chekhov gently skewers Vanya because he is a middle-class man who is just as much (if not more) to blame for his follies and failings than anyone else is. He's not a true tragic hero because he's much too melodramatic and ridiculous.
I do believe I'm a little attracted myself.
It's amusing to listen to Helen almost talk herself into liking Astrov, which is exactly what she does here. She is unhappy in her marriage to a much older man, and she's unhappy in life in general. She is bored, restless, and finds no purpose for herself. Thus, she seems to enjoy occasionally creating a bit of drama for herself, which can be seen in the way she talks to Vanya, her plot to intervene for Sonya, and here with her comments about Astrov. She muses on how interesting and different he is, and how she might just be attracted to him. Ultimately, though, she feels no real passion for him, and she will not take the step to be unfaithful to her husband. She continues to live in her unhappiness and malaise because it is easy and familiar..
If I'd had a normal life I might have been a Schopenhauer or a Dostoevsky.
This is one of the most laughable and absurd of Vanya's protestations. He viciously attacks Serebryakov as the ultimate source of his misery and claims that, were it not for the professor, he would have been able to develop his genius tendencies. And yes, those two men were geniuses—not just people who "did something" with their lives. Vanya has inflated his abilities to a preposterous level: all he really does when he is not working is sit and stew and blame others for his miserable existence. Serebryakov may be obnoxious, pretentious, and self-centered, but he's no Machiavellian villain.
We'll go back to our old way of doing things...
Marina expresses her desire to go back to the old way of life on the estate; this is both understandable, given the drama that just ensued, and a little problematic, given that the lack of change in parochial Russian life seems to be slowly crushing its victims. However, this statement works in another way as well: it indicates what the whole plot has come to—or, rather, what it has not come to. Nothing is changed: everyone survives and will go on much as they did before. Chekhov's plays are about real life and everyday people, finding a bit of beauty and many laughs in their attempts to find meaning.