The Impossibility of Reason is the second studio album by the American heavy metal band Chimaira, released on May 13, 2003. It is the first album to feature Matt DeVries on rhythm guitar. The album is a noted for its groove metal-oriented sound, especially when compared to the band's previous releases which were considered closer to the nu metal genre. Upon release, it debuted No. 117 on the Billboard 200 charts. To date the album has sold around 200,000 copies in the US.

Chimaira is an American heavy metal band from Cleveland, Ohio. Formed in August 1998, the band's name is derived from the word Chimera, a monstrous creature in Greek mythology. Throughout its history, the band had numerous line-up changes, leaving vocalist Mark Hunter as the only constant member. The band dissolved in 2014, but announced a reunion in 2017 and a return in 2023 with most of the group's longtime members rejoined.