Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Q: Which analgesic drug, first isolated in 1804, was named after the Greek god of dreams ?

A: analgesic
****
Q: The bells were ringing for Chuck Berry when this song made it to No1. His first and only British No. 1. What song?

A: chuck berry
****
Q: Which 20th century philosopher wrote 'Being And Nothingness' and 'Critique Of Dialectic Reason'?

A:
being and nothingness
****