“Symptom of the Universe” is widely considered a ‘proto-thrash metal song’ (just like “Into the Void”), it isn’t thrash, but influenced many thrash metal bands, like Metallica. The lyrics to this song are about a dream that Geezer Butler once had.

The song starts with a very aggressive guitar riff, the song structure and feel changes drastically during the outro, including acoustic guitar and piano, giving Ozzy the opportunity to show his vocal skills.