The thinking-man's-metal tag that hangs on Isis seems bad for business, but guitarist/vocalist Aaron Turner and his comrades don't appear to mind. After all, the jacket of their new CD includes the quote ("Nothing is true, everything is permitted") that inspired the album's title, as well as a quasi-footnote conceding that historians debate whether the line should be attributed to the 11th-century missionary most often given credit for it. Then again, honesty in advertising is appropriate, since Isis' exciting work requires that listeners know how to use their heads for something other than banging. Every track here, from "Wrists of Kings" to "Garden of Light," contains more than its share of fascination but "Dulcinea" could serve as a template. The tune juxtaposes lovely singing and harsh growling, not to mention delicate guitar arpeggios and surging power chords, even as it makes room for Aaron Harris' roiling drums, Jeff Caxide's inventive bass lines, and Bryant Clifford Meyer's atmospheric electronic treatments. The results prove that beauty and brutality aren't mutually exclusive. And that's the Truth.