Radiohead frontman Thom York has said of this track; "That song literally took five minutes to write, but yet it came from all these mad places. [It's] something I never thought I could actually get across in a song and lyrically. [But I] managed it and that was really, really tough. [Physicist] Stephen Hawking talks about the theory that time is another force. It's [a] fourth dimension and [he talks about] the idea that time is completely cyclical, it's always doing this [spins finger]. It's a factor, like gravity. It's something that I found in Buddhism as well. That's what Pyramid Song' is about, the fact that everything is going in circles." According to Colin Greenwood, it was the image of "people being ferried across the river of death" that most affected York. This is reflected in the song's many references to Dante's imaginary journey through ****, Purgatory and Heaven, Divine Comedy. These include the black-eyed angels, a moon full of stars and jumping into the river.