[2] In an interview with NPR Music about the release of that single, the band wrote, "Sleep has been sporadically writing riffs for a while now [...] There is no preconceived idea of what the new material should be.

Musically, The Sciences is a stoner metal[5] album built upon the distorted, downtuned, and slow bass of Al Cisneros playing alongside the similarly low guitar of Matt Pike.

[9] Along with the cannabis references, The Sciences makes multiple allusions to Birmingham heavy metal pioneers Black Sabbath, whose sound inspired the band.

[16] In the review for AllMusic, Mark Deming compared the album to the band's previous release, claiming that "The Sciences may not be as daring and ambitious as Dopesmoker, but it finds Sleep working at the top of their game in the studio, and their resinous howl is still a weird marvel to behold.

"[17] Dan Franklin of The Quietus praised The Sciences, writing, "Sleep present an alternative pathway for the hyper-technological age.

[6] Fred Pessaro of Revolver lauded the album, calling it "the best stoner-doom record we've heard in a long time.

"[5] Writing for Metal Injection, Greg Kennelty said, "The Sciences is the first Sleep album since 2003's Dopesmoker and is very much worth the wait, if not heavier than expected.

"[24] Writing for Pitchfork, Grayson Haver Currin considered the album an ideal comeback for Sleep, saying that the six songs "burn perfectly".