Character Analysis
If Dr. Stone is a deadbeat dad, Dr. Ghosh is the exact opposite. He starts off the novel mooning over Hema, whom he's loved for years but who won't return his affection, and he ends up as her husband and the adoptive father of her children. His devotion to Hema and the boys is absolutely unwavering, and he seems to dedicate his life as a family man to just being a really good guy.
Lacking Confidence
Because the love of his life, Hema, ignores him like the little red-haired girl ignores Charlie Brown, Ghosh is kind of a stick in the mud at the beginning of the novel. For example, when he had taken Hema to the airport before her trip to India, "he'd been dying to blurt out, Hema, let's get married. But he knew she would have thrown her head back and laughed" (2.11.4). No guts, right?
And no glory. What does Ghosh's sheepishness get him? Not much: a boring life filled with visits to prostitutes he pretends are someone else: "Much, much later, they retired to the back room; he closed his eyes and pretended, as he always did, that she was Hema. A most willing Hema" (2.11.92). Ghosh, rather than taking a risk and telling Hema how he feels, would rather just suffer and live in a fantasy world.
A True Scientist
While Ghosh might be a bit of a loser in his love affairs, his natural curiosity makes him a fine doctor—though it takes Hema's nudging to really get him to be confident there, too. Ghosh suffers from some sort of STI and treats the whole situation like a science project. Now here's an experiment your teacher might not expect at the science fair:
Was this mysterious irritation from lack of use? Or from a kidney stone? Or was there, as he suspected, a mild, endemic inflammation along the passage that carried urine out? Penicillin did nothing for this condition, which waxed and waned. He'd devoted himself to this question of causation, spending hours at the microscope with his urine and with that of others with similar symptoms, studying it like the piss-pot prophets of old. (2.11.28)
That ability to transform an uncomfortable and worrying personal experience into a scientific question that could, if answered, help not only himself but others as well is what makes Ghosh a true research doctor and all-around good guy. He passes the scientific rigor onto his kids, who both become, in their own ways, amazing, even selfless doctors.