Both men are well-read philosophers in their own right, both come from well-off families, neither sleeps easily.  The commonalities between them show how little truly separates these two men that, according to their relationship, should be on levels further divided from each other.  Ivan is critical, somewhat pessimistic, untrusting, while his doctor assumes a quieter role; he listens more than speaks, he remains calm even when Ivan becomes upset.  Their conversations are meant to shed light on the nature of people that society has brushed off as no longer functional (Ivan).