If you are ever in a discussion with an pro-abortionist who attempts to make the case that the unborn are in some way different from other human beings and therefore fall under a category that does not require the protection we give to those who actually can defend themselves, there is an easy way to help them clarify the indefensibility of their position. It's simple to remember and it goes like this ...
The differences between you and an unborn human being can be summarized as falling under one of the following four categories, none of which qualify as justification for taking its life:
Yes, the unborn is smaller than you. But you are also smaller than Shaquille Oneal. Does that mean you are somehow less valuable than Shaq? Does the size of a thing define its worth? Let's hope not.
Level of Development
Yes, the unborn is less developed than you. But so is a 3 year-old little girl less developed than her 35 year-old mother. Does her level of development make the 3 year-old less worthy of life than her mother?
Location, location, location. It may define value in real estate, but it certainly does not do so in the measure of our humanity. Does where you are define what you are? If I move from the family room to the driveway, am I somehow less valuable as a human being? The answer is obvious -- just as obvious as the fact that moving several inches down the birth canal does not somehow increase the value of the human being who, moments before, resided in his mother's womb.
Degree of Dependency
Yes, the unborn is more dependent on its mother than a grown man. But how does one's level of dependency change one's value as a human being? Left alone in the woods behind your house, your 3 year-old child would most certainly die of exposure and starvation. He is fully dependent on you, his parent, to survive. How is it that you would charge someone who did such a thing with negligent homicide, yet you use the same logic to rationalize abortion?
Obviously, these four criteria do not in any way serve to define a difference in value between those the pro-abortionist will not protect and those they will -- those, say, like themselves. The SLED test is a quick and powerful way to make that point.