The Pearl is often hailed as a critique of the American Dream. It argues that opportunity is not equal, and that such an idealistic notion is impossible in a corrupt, imperfect world. Though the main characters in the novel are destroyed because of their pursuit of a better life, the novella in no way condemns dreaming or the desire for something more; the text explicitly says that the ability to want more is the defining characteristic of man – it is what separates him from mere animals.
Because Kino gives up on his dream at the end of the text (signified by throwing the pearl back into the ocean), it is at this moment – not earlier – that he becomes an animal rather than a human being.