Some might argue that machine ethics obviously exists because humans are machines and humans have ethics. A wide range of positions on machine ethics are possible, and a discussion of the issue could rapidly propel the people into deep and unsettled philosophical issues. Computer scientists and engineers must examine the possibilities for machine ethics because, knowingly or not, they've already engaged-or will soon engage-in some form of it. Many believe a bright line exists between the senses of machine ethics discussed so far and a full ethical agent. The bright-line argument can take one or both of two forms. The first is to argue that only full ethical agents can be ethical agents. The other form of bright-line argument is to argue that no machine can become a full ethical agent—that is, no machine can have consciousness, intentionality, and free will. Thus, both forms of the bright-line argument leave the possibility of machine ethics open.