The text of the novel is the narration of Edward Prendick who is a shipwrecked man rescued by a passing boat. He is left on the island home of Doctor Moreau, a mad scientist who creates human-like hybrid beings from animals via vivisection. The novel deals with a number of philosophical themes, including pain and cruelty, moral responsibility, human identity, and human interference with nature.

References:
https://en.wikipedia.org/wiki/The_Island_of_Doctor_Moreau