I have been asked the question about ethics twice in a week. It all started with I brough a brochure of books about ethics from a philosophy conference to work. Somone saw the front page of the brochure without reading into it asked me am I very ethical after reading those ethics books. Then I couldn’t help myself explaining the three levels of ethics to them. His question is merely asking the most mundane level of ethics, descriptive ethics, which judge whether ones actions or thoughts agree with a set of preassumed ethical rules or framework. It is kinda like asking whether buring the flag is illegal based on the consitiution. The more interesting kind of ethics is normative ethics, which determine which set of ethic framework we should subscribe to. It is kinda like asking whether we should adopt the common law, civil law or sharia law. The last level is ethical theory, a quest for pure knowledge. What is the word “ethics” means, where ethics comes from. It is kinda like asking what is “laws”, why do we need laws. There are four main ethical theories, John Stuart Mill’s utilitarianism, Immanuel Kant’s duty ethics, John Locke’s rights ethics and Aristotle’s virtue ethics. I think there should be a fifth kind of ethical theory, Charles Darwin’s efficient ethics. That would be a very interesting philosophy research topics.