Character Analysis
Poor Little Boy
The first thing we find out about Doctor Zhivago in this book is that he wasn't always Doctor Zhivago.
Yup, this dude used to be a cute little kid.
Now, little Yuri had to grow up pretty quickly after his father deserted him and his mother died. He doesn't know a whole lot about his father, because his mother tends to keep stories about Daddy Zhivago on the down low: "While his mother was alive, Yura did not know that his father had abandoned them long ago, had gone around various towns in Siberia and abroad, carousing and debauching, and that he had long ago squandered and thrown to the winds the millions of their fortune" (1.3.1).
So yeah, let's say that Yuri Zhivago's young life doesn't start in the best of ways. But as bad as losing his father is, losing his mother is ten times worse for him. After she dies of genetic heart failure, Yuri finds that "[over] the lawns in an auditory hallucination hung the phantom of his mother's voice; it sounded for him in the melodious turns of the birds and the buzzing of the bees" (1.6.2).
This is a key line not only because it shows us how much his mother's death affects little Yuri, but also because it shows how he thinks of nature as a sort of stand-in for his mother. This will help explain why Zhivago feels so at one with nature in the rest of the book. He really does feel like he's a part of it, and it's a part of him.
Even though Zhivago spends much of his young life living in poverty with his mother, the truth is that his father was a very rich man. Worse yet, everyone in Russia knows this, which makes things rough for Zhivago and his family when the Communists take over the country. Turns out that Communists weren't the biggest fans of people from rich families.
Lover (Hypocrite?)
When he grows up into a young man, Yuri Zhivago becomes a doctor and gets married. He seems to care a lot about Tonya, the woman he marries, but it's not clear if they're getting married because they love each other or because Tonya's mother asked them to as a deathbed request. Zhivago and Tonya are both young and sweet, and they both want to please old Anna Gromeko; it's not clear if they quite know what they're getting into.
After Zhivago gets called away to serve as a doctor in World War I, though, he falls in love with a woman named Lara Antipova, even though he's already married and has a son. To be fair, the guy makes an honest effort at first to stay away from Lara and not love her: "To this new [period] belonged Yuri Andreevich's honest trying with all his might not to love [Lara]" (5.15.9). Unfortunately, fate has a way of throwing Zhivago into Lara's company, and eventually the guy gives into temptation and starts having an affair with her.
Now, this isn't to say that Zhivago doesn't love his wife Tonya. In fact, the guy is downright violent at the thought of anyone disrespecting her. The problem is that he's the one who keeps disrespecting her, and the narrator sums up his problem nicely by saying, "In defense of her wounded pride he would have torn the offender to pieces with his own hands. And here that offender was he himself" (9.16.4).
Still trying to do right by his wife, Zhivago decides one day (while coming home from Lara's) that he's going to start being more honest with his family and make things right. The narrator tells us that Zhivago "had decided to confess everything to Tonya, to beg her forgiveness, and not to see Lara anymore" (9.16.9). The problem is that this also happens to be the day when Zhivago is kidnapped by a wacky militia and forced to travel hundreds of miles away from his family to fight in a war he doesn't care about.
By the time he makes it back to his family's home, they've been deported. So he decides to make the best of a bad situation and settles down to live with Lara instead of going after his family. If you're feeling judgmental, you should keep in mind that getting out of a massive country in the middle of a civil war to join your deported family isn't as easy as it sounds. Wait, did that even sound easy?
That's not to say that Zhivago has no choice; it's just that the choices that he and other characters in the novel have to make are usually really tough ones with big, sometimes deadly consequences either way.
Doctor Life
From a young age, Yuri Zhivago shows that he's not like other people. In fact, Pasternak almost never wastes an opportunity to tell us this. Early on, we find out that "[everything] in Yura's soul was shifted and entangled, and everything was sharply original—views, habits, and predilections. He was exceedingly impressionable, the novelty of his perceptions not lending itself to description" (3.2.3).
So what we know at this point is that Zhivago is like a sponge, soaking up whatever he sees and hears. But here's the thing—he soaks things up in an original way because he has a very unique mind. And it turns out that being an original thinker isn't the best thing in the world if your country is taken over by radical Communists.
While the world around him becomes more obsessed with war and politics, Zhivago turns to art as his main interest. For him, "art is always, ceaselessly, occupied with two things. It constantly reflects on death and thereby constantly creates life" (3.17.12). Or in other words, people might spend their lives trying to get political power, but the truth is that everyone dies at the end of the day, and the only way to defeat death (even if it's temporary) is to create art, which creates life.
So Zhivago is really a doctor in two different ways. Yeah, he's literally a doctor, but he's also a metaphorical doctor: he creates and sustains life through art.
It's no accident, by the way, that Zhivago's name comes from the Russian word for "life." Pasternak himself was totally obsessed with the idea of life (the title of his most famous book of poetry is actually My Sister, Life). He wanted to live life to the fullest, and for him, that meant experiencing nature, falling in love, thinking independently, and creating art. For Pasternak, without nature, love, independent thought, and art, there was no life.
Zhivago feels the same way, and it's these types of independent thoughts that eventually make the Russian authorities target him as a traitor. Worse yet, the dude refuses to flee Russia because he's too stubborn in his individualism to let the government tell him what to do. Somehow, the guy manages to avoid getting arrested. But for the last ten years of his life, he lives a pretty bad existence because he's never quite wanted by the society around him.
That's the price of being an individual in the Soviet Union, but we think that for Zhivago, it would be even worse to give up his individuality and ideals just to be accepted.
Yuri Zhivago's Timeline