Pro-choice people may be concerned about other choices, and pro-life people may be concerned about other lives, but the pro-choice viewpoint is specifically concerned about the choice to abort or not, and the pro-life viewpoint is specifically concerned about the life of the fetus.
If you are concerned about the life of the fetus and think abortion should be illegal than you are pro-life, by the standard definition, even if you aren't concerned about the life of cats, or the lives of people on death row ect. There are of course pro-life people who are concerned about those lives as well but that is not what gets them to be defined as pro-life.
Similarly if you are pro-choice you may or may not be concerned about school choice; you might support a draft in certain circumstances (and thus be against people's choice not to join the military in certain situations), even if those circumstances only include war on the scale of WWII, or you might not; you might be concerned about any number of other types of choices or you might not. Neither position on any of these issues but abortion makes you pro-choice or not. You could be for having as many choices available as possible in almost any number of areas but if you think abortion should be outlawed you are not pro-choice. OTOH other choices might concern you very little, but if you oppose making abortion illegal you are pro-choice.
Saying all of this is not a slander against either the pro-life or the pro-choice side. Its just how those sides are defined.
JohnM wanted to withhold the term pro-life because you can be for outlawing abortion without caring about other forms of life. That is true, but can also be pro-choice without being concerned about other choices. This doesn't mean that pro-choice people always are, or have to be, or even usually are only focused on choice in regards to abortion, but that is what defines them as pro-choice.
Tim |