One question that has been discussed in class is whether or not Marlow is a reliable narrator. Personally, I think this is a very interesting question, because I believe that the answer is simultaneously "yes" and "no." I feel that the dominating answer depends on what criteria you base reliability on. From the viewpoint of Marlow as a human being recalling a part of his life, he is very reliable compared to most people. He is remarkably accurate on certain details and seems to have an unusual lack of emotional or opinionated bias on many elements of his story, which leads him to simply describe an event as he saw it rather than put a clear spin on it and eliminate or add certain aspects. He even states that he wants to focus less on what happened to him personally as he begins his story. Most people do not remember very small details of their past as well as he does, and they also apply their bias to their stories. In this sense (comparing Marlow to most people telling a story), I believe he is a pretty reliable narrator.
However, in the context of a novel, he is a fairly unreliable narrator. In many novels, the narrator is either omniscient or is capable of remembering far more than the human capacity for remembering an event. Thus, we as readers are often spoiled by narrators who can tell a story from every different viewpoint to ensure accuracy and unbiased storytelling. In comparison to these stories, Marlow is unreliable due almost entirely to his humanity. By nature, he can only view the events that transpired from his own perspective, thus he can only tell the story one-dimensionally. We, the readers, are left to fill in other perspectives ourselves.
Thus, I believe that this question is far more complex than it is for most novels, and I am curious to see how others feel about this topic.