Opiate

This relates to Karl Marx's statement that "Religion is the opiate of the masses." People relied on the church for direction in their lives, and carried on with their lives. Marx felt that the church kept people from "waking up and smelling the coffee." This is one of the themes of the CD: the band makes fun of the way people let others think for them. That is, it's one thing to have religious beliefs, but it's another thing to let someone else interpret those beliefs and force them on you.

A telephone rings at the very end of the song. it starts at 4:44 and rings only twice.

According to Tool drummer Danny Carey in Revolver Magazine Presents Tool, "A lot of the songs for Undertow were already written when we did Opiate, but we felt like no one would take us seriously unless we recorded only our most aggressive, in-your-face song and put them out there at one time. And I think that got us typecast as a metal band. It's kind of funny, because the song I thought was the least aggressive, 'Opiate,' was the more popular on the record."