Lovecraft's materialist views led him to espouse his philosophical views through his fiction; these philosophical views came to be called cosmicism. Cosmicism took on a dark tone with his creation of what is today often called the Cthulhu Mythos, a pantheon of alien extra-dimensional deities and horrors which predate humanity, and which are hinted at in eons-old myths and legends. The term "Cthulhu Mythos" was coined by Lovecraft's correspondent and fellow author, August Derleth, after Lovecraft's death; Lovecraft jocularly referred to his artificial mythology as "Yog-Sothothery".