Like its predecessor, _Sleep of Reason_ is loosely based on doom metal, but shuns the slow pace commonly associated with the genre and contains a generous pinch of pop. There are still some relatively plodding passages ("To Drown", "Beneath the Soil"), but things tend to stay sufficiently mid-paced and lightweight to be more palatable for an audience that transcends doom metal aficionados. Furthermore, the music can get rather upbeat and chorus-y at times, with melodic doom metal turning into something altogether more commercial -- and unfortunately losing much of its appeal in the process ("Hollow Inside", "In My Skin").

Judging by the slower tracks, The Eternal could have created a solid doom metal album if they had so wished. Instead, they opted for something far more ambitious; and in doing so, they failed to fulfill the potential they show on the better parts of the album. _Sleep of Reason_ has some good moments, but ultimately it is doomed to oblivion as far as I am concerned.