Jack London spent much of his young life in the Arctic North and returned to America a changed man. He believed that society and its modern conveniences had made everyone unappreciative of the power of nature and weak in general because they relied too much on science and technology. He felt that people needed to rediscover their natural animal instincts if they wanted to remain strong and at the top of the food chain in the modern world. London read Darwin's "On the Origin of Species" and Herbert Spencer's "First Principles" many times, influenced by Darwin, and used them as sources to help him write his stories. In an article about London's life titled "Jack London and Evolution: From Spencer to Huxley" by Lawrence I. Berkove, he writes "A copy of Origin to Species was one of the few books London had with him in the Yukon." Darwin had a great influence on London as Darwin is mentioned many times favorably in London's letters. The influence of evolution and Darwinism on London, and his personal life experiences, are what make his stories so real. He understands the settings of "To Build a Fire" and "Law of Life" enough to be accurate when using images to describe it and to know what those settings mean to a human being just within them. Most of London's stories are set in the Yukon, where he spent his time, so that's also what makes his stories so true. Another aspect of realism used by London is the lack of romance in the fate of the characters. London doesn't seem to care about pleasing the reader and letting its characters live. It doesn't make Koskoosh in "Law of Life" fight wolves to try to survive, or make the man in "To Build a Fire" successfully start a fire, because in the real world, in these places, those things they would actually not happen. London sticks to the truth about the characters' fates in this setting, which makes these stories successful