Pavel is an elderly Jewish man who had been banned from practicing medicine during the war, under the Anti-Semitic laws of the Nazi government. Under Nazi law, the medical licenses of Jewish physicians were cancelled in 1938. The novel takes place in 1942, during the height of power held by Germany and its allies during the Second World War.
When Bruno falls off the swing and injures himself, Pavel attends to his wounds and assures the boy he will not need stitches. Bruno questions this and tells Pavel he is not a doctor. Readers are not informed where the man comes from, or what discipline of medicine he is in, only that he was a physician:
I certainly am a doctor. Just because a man glances up at the sky at night does not make him an astronomer, you know.
Bruno’s childish logic is as follows: Pavel is a waiter for the commandant at "Out-With"; therefore he cannot be a doctor. Bruno is largely unaware of the circumstances Jews have been placed under during the war; he is naïve to the fact that thousands upon thousands of Jews were forced to give up their occupations to serve the Nazis. Pavel’s response conveys the idea that appearances are not all that they seem.