A child sees the bulletin of the Synagogue announcing that the congregation had just hired a new rabbi, his name is Rabbi Dr. Epstein. The child is so excited that the new rabbi is also a doctor, that the next time he has a stomach ache, he calls the Synagogue.
“I would like to speak to the Rabbi Dr.,” the boy says.
The rabbi gets on the line and asks how he can be of help.
“Well rabbi, the boy says, I have a stomach ache and I was wondering what you suggest I do.”
“Sorry son, I’m not a medical doctor,” replies the rabbi.
“What type of doctor are you?” asks the boy.
“I am a Dr. of Philosophy,” was the response.
The child thought for a moment and then asked, “What type of sickness is that?”
Source: here