Uncle Vanya is thematically preoccupied with what might sentimentally be called the wasted life, and a survey of the characters and their respective miseries will make this clear. Admittedly, however, it remains somewhat difficult to organize these concepts into a coherent theme as they belong more to the play's nastroenie, its melancholic mood or atmosphere, than to a distinct program of ideas.
One obvious characteristic of the play is that almost all the characters are consumed with lethargy, boredom, and regret over their unsatisfactory lives. They bemoan their old age, mourn the years that they have wasted in drudgery, pine over lost loves, and muse bitterly over what might have been if their lots had been different. They thus suffer from a sense of loss without knowing exactly what has been forfeited. Throughout the play, their private reflections burst through the surface of the everyday, giving way to torrents of unhappy introspection.
Uncle Vanya, the eponymous hero (an eponym being a real or imaginary person for whom something is named), is deeply embittered over having spent his life toiling for the benefit of Serebryakov, a once-worshipped scholar that Vanya has discovered to be a charlatan. Astrov, the region's doctor, laments the onset of age: his hard years in the country have left him numb to the world. Vanya's mother Maria pathetically fends off her unhappiness by studying pamphlets. Yelena, Serebryakov's wife, finds herself bound to a miserable husband whom she does not love. As for himself, the professor, having retired from public life, feels consigned to the tomb that his estate represents. Finally, his homely daughter Sonya has resigned herself to a loveless, monotonous life, awaiting the peace that death will bring. For all these disparate reasons, Uncle Vanya's characters feel trapped in their hopeless existences, mourn unrecoverable losses, and harbor deep resentment for those around them: the result is a volatile household in which all, to quote Yelena, has gone to "rack and ruin."
Inseparable from the theme of wasted lives is one we might sentimentally dub that of the impossible love. We can best appreciate the significance of this theme by first briefly considering the play's generic context. As discussed in the Context, Uncle Vanya is a revision of an earlier Chekhov play; in some sense it is thus also a rewriting of the conventional melodramatic plot that he heavily relied upon. Like most works of turn-of-the-century melodrama, The Wood Demon—Vanya's precursor—is organized around a structure of erotic intrigue involving three couples, the plot putting them through passionate seductions, arresting complications, desperate hand-wringing over hopeless romances, and a happy ending. Vanya also repeats this structure of erotic intrigue, but, he does so with a marked difference. The seductions are awkward and stilted, boorish and bungled, the players are indifferent to, oblivious to, or repulsed by each other, and, ultimately, their games leave everyone in a miserable situation. What we are charting here then is both a subversion of genre as well as an erotic subplot that is consistent with the thematic concerns of loss, regret, and the wasted life discussed above.
To make his remarks more concrete, we can survey the fate of Uncle Vanya's couples here. One consists of the decrepit Serebryakov and his beautiful wife Yelena. At best "fascinated" by the professor long ago, the latter does not love her husband, as she feels "incidental" in her married life. Nevertheless, Yelena remains with her husband—whether out of conscience, convention or inertia remains unclear. Our second intrigue involves Yelena and the desperate and crude Voynitsky, who hopelessly makes advances on her throughout the play (perhaps in some fantasy of liberating them both from their bondage under the professor). With Yelena, Voynitsky is consumed with thoughts of what might have been if he had married her before his bitter enemy did. Yelena rejects him wholeheartedly, finding in his declarations of love an impulse to destroy her. Third, we have the homely, gentle Sonya who loves Dr. Astrov and enlists Yelena as her advisor and helpmate: yet, Astrov is entirely indifferent to Sonya and her love-worship.
Ironically, Astrov does, however, find himself drawn to Yelena, and Yelena, herself, is attracted to Astrov as well. Their relation probably structurally resembles one from conventional melodrama, posing a younger, impassioned hero who by all counts should rescue the beautiful wife from her unhappy marriage (indeed, in The Wood Demon,Uncle Vanya's precursor, their intrigue takes on this form). Astrov and Yelena's courtship, however, is decidedly unromantic, made abrupt and disjointed through indirect action and Astrov's boorishness, and based on little more than a vague sense of fascination on both sides. Ultimately they part ways with regret, left to muse on what might have been. Their interaction recalls Yelena's sense that she is but an incidental character in her love affairs and Astrov's lament that he has "no relationship" with anyone. Indeed, the strangeness and alienated quality of their affair lies in the absence, on this stage, of the erotic relation as conventionally conceived.