Lyric discussion by sandt38 

Cover art for Pneuma lyrics by Tool

Its about societal constraints.

Basically we are born into society that expects us to conform. One foot nailed down. But we need to look outside what is expected, required, or deemed acceptable. Bound to reach out and beyond this flesh.We are will and wonder. But we get pulled back into what is expected of us.

The song continues with stepping out (think Lateralus) yet being drawn back.

It's a reminder of the idea that we need to explore, go beyond societal, and organized religious restraints.

@sandt38 One foot nailed down, means that you can only keep walking around in circles and never get anywhere....