In ethics it is very important to communicate with clearly defined terms. This becomes especially important when dealing with a very divisive topic such as abortion. Fifty years ago, in the ethical debates about abortion, some expressed concern about how the term human being was used by those who claimed that abortion was wrong. The basic argument for the position that abortion was wrong went like this: It is wrong to kill an innocent human being. A human fetus is an innocent human being. Abortion involves killing a human fetus. Therefore, abortion is wrong. It was claimed that this was not a proper argument because the term human being meant different things in two of the premises. In the first premise human being means an individual with full moral status, but in the second premise human being is used in its biological sense. The claim was made that not everyone believes that every member of the human species has full moral status, so we should not use the term human being in this argument. It was proposed that everyone involved in the discussion abortion use the term person to represent those individuals who have full moral status. Since this discussion in the 1970s the term person has been used in the ethics literature as a technical term which is defined as those individuals who have full moral status.
However, it seems to me that the term person has the same problem as the term human being. In common usage it means other things than individuals with full moral status. It is commonly used to refer to adult human beings although children are sometimes included in who we think of as persons. It many times means those with whom we communicate and have a relationship. In legal terms it means something different. It refers to those who have certain rights and responsibilities under the law. It involves those who can be held accountable for their actions and those who can do such things as owning property and entering into contracts. The legal definition a person can include entities that are not human beings such as corporations. This becomes a problem when we look at how we define who is a person. Instead of looking at how we should understand who has full moral status, we tend to look at who fits with how we commonly use the term person. The Supreme Court in Roe v. Wade stated that “the unborn have never been recognized in the law as persons in the whole sense,” but that does not necessarily mean that the unborn do not have full moral status. Mary Ann Warren asserted that it is those who we consider to be persons rather than those who are genetic human beings who make up the “set of beings with full and equal moral rights.” However, she defined personhood based on cognitive capacities that are characteristic of fully healthy adult human beings who are moral agents and leaves out many, such as infants and those with cognitive disabilities, who we would commonly consider to have full moral status.
Using the terms human or human being to represent those who have full moral status assumes that all biological human beings have full moral status. Using the term person to represent those who have full moral status assumes that having full moral status is based on something other than being a biological human being. But that is the question. What we are trying to decide is whether it is correct to decide who has full moral status based on being a member of the biological category of beings we call human beings or based on having certain cognitive attributes or capacities. Since both terms essentially beg the question, it would be better to use neither. In discussing whether a fetus or some other individual has full moral status we need to focus on how we decide who has full moral status and recognize that using the terms human being or person in a moral sense represent positions on that issue.