Science can be a wonderful tool in the pro-life advocate’s arsenal.  However, science can’t dictate morality, it can only inform morality. Science can tell us that something we are harming or killing is human; science can’t tell us that it’s wrong to kill that human. So while we can demonstrate scientifically that the unborn are living human organisms from fertilization, we must turn to philosophy to demonstrate whether we can or cannot kill that living human organism.
It seems to me that the burden of proof should always be on the one wanting to take life. As I mention in my article on science, if we don’t know when human life begins (even though we do), the benefit of the doubt should always go to life. As I’ve demonstrated elsewhere, no pro-choice argument is powerful enough to justify killing the unborn human. I’ve looked at pro-choice arguments for personhood and bodily rights.  But now I’d like to turn to some basic philosophy, and look at the bad arguments that people use on both sides of the abortion fence. In this article, I’ll look at logically fallacious arguments. In my next article, I’ll look at arguments that aren’t necessarily fallacious, they’re just bad arguments.
Before we can look at what makes a bad argument, first let’s look at what makes a good argument. A lot of arguments you’ll find are written in essay form. This is fine; most of my articles have been the same. But usually it’s easier to see if an argument works if you put it in the form of a syllogism. A syllogism is simply an argument composed of premises that lead to a conclusion. A basic syllogism has two premises and one conclusion, but arguments can have more premises, and even more conclusions, than that. Here is a basic example of a syllogism:
P1: All men are mortal.
P2: Socrates is a man.
P3: Therefore, Socrates is mortal.
This is an example of deductive logic. Deductive logic argues from a general idea (that all men are mortal) to a specific case (that Socrates, being a man, is mortal). A premise is made up of a statement that can either be true or false. If all the premises are true, then the conclusion can’t be false.
If the conclusion follows necessarily from the premises, then the argument is valid. An invalid argument is one where the conclusion doesn’t follow from its premises. An argument is sound if it is valid, and all of its premises are true. If the argument is invalid, or if it can be demonstrated that one or all of the premises are false, then an argument is unsound. So an argument can be valid, but unsound. An argument can even be invalid, but have a true conclusion (you just arrived at it through bad reasoning). But an argument can’t be invalid and sound.
The argument I generally make for the pro-life position is as follows:
P1: It is prima facie immoral to kill a human being.
P2: Abortion kills a human being.
C: Therefore, abortion is immoral.
Premise one can be supported because human beings are inherently valuable based on the kind of thing they are, human beings. All human beings have the inherent capacity as rational, moral agents. It is just as immoral to kill an infant as it is to kill an adult.
The term prima facie is Latin for “at first sight.” I insert this phrase because most pro-life advocates agree that sometimes killing is justified, such as in self-defense. Some pro-life people believe that capital punishment and just war are also justified forms of killing. The idea here is that under most circumstances, it is wrong to kill a human without moral justification. Abortion is an unjustified form of killing.
Premise two is supported through science. We know that all human beings are living human organisms from fertilization.
So the conclusion necessarily follows. If it is immoral to kill human beings, and the unborn are human beings, then it is immoral to kill them.
So we see that it’s immoral, but should it be illegal? Well, I add a premise and a conclusion to show that abortion should also be illegal. My updated argument looks like this:
P1: It is prima facie immoral to kill a human being.
P2: Abortion kills a human being.
C1: Therefore, abortion is immoral.
P3: The unjustified killing of human beings is illegal (e.g. murder).
C2 (from P2 and P3): Therefore, abortion should be illegal.
Premise three is supported because we do make the unjustified killing of human beings, like murder, illegal. In all civilized societies, murder is always illegal (although we sometimes disagree over what constitutes murder).
So conclusion two necessarily follows that abortion should be illegal.
A logical fallacy is simply a flaw in your reasoning. There are two kinds of logical fallacies: formal logical fallacies and informal logical fallacies.
In a formal logical fallacy, there is a problem with the form of the argument itself. In an informal logical fallacy, the problem stems from a flaw in reasoning that causes the conclusion not to be supported by its premises. There are many common fallacies made by people who argue in the abortion issue. We’ll be only looking at informal fallacies, since these are the most common.
Appeal to pity
X is in a pitiful situation.
Therefore your argument fails.
An appeal to pity is where someone claims that an argument fails because someone is in a pitiful situation. A common example of a pro-choice appeal to pity is that abortion is needed because some women are too poor to afford a child. This would be represented as follows:
P1: Some women are too poor to raise a child.
C: Therefore, abortion should be legal.
But how does it follow that because someone is too poor to raise a child, we may kill the child? Ask yourself if a woman may kill her two-year-old child because of poverty? Of course not. So why would we justify abortion for the same reason?
X is a horrible person.
Therefore, X’s argument fails.
This one seems to be everyone’s favorite fallacy. Ad hominem is Latin for “to the man.” In this fallacy, you are simply attacking the character of the person making the argument, rather than the argument itself. An argument does not succeed or fail based on the person making the argument.
A common pro-choice ad hominem fallacy is that men have no say because they can never get pregnant, which I have responded to in a previous article.  A common ad hominem fallacy from the pro-life side is that pro-choice people hate babies. Most pro-choice people don’t hate babies, but even if they did, how would it follow that their argument fails because they hate babies?
X believes Y.
I’ll attack argument Z.
Therefore argument Y fails.
A strawman argument is when you attack a similar but different argument than the argument presented because it’s easier to refute.
A common argument you hear from pro-choice people is that pro-lifers want to enslave women. No pro-lifer wants to enslave women. But it’s easier to dismiss the pro-life position when making such an extreme claim.
Another argument you hear is that skin cells are human, so pro-lifers should be against the death of skin cells (they might make their argument a bit more colorfully, like saying if abortion is homicide, then masturbation is mass murder). But here, they’re actually attacking a strawman. We don’t claim that it’s wrong to kill skin cells. This is because there’s a difference between a skin cell and an unborn human. The skin cell is just part of a larger organism; left on its own, it will never be anything but a skin cell. However, the unborn human is an organism, developing itself from within into a more mature version of itself, along the path of human development. There’s a major difference between the two.
Begging the question
This is one that confuses a lot of people. Usually when someone says “that begs the question,” they really mean “that raises the question.” But when someone begs the question, they assume that a statement or claim is true without evidence other than the statement or claim itself.
Pro-life people do this a lot, when they talk of abortion killing a baby. If your argument includes talk of killing a baby, but you have not proven whether or not the unborn are babies, you are begging the question.
Pro-choice people do this, too, usually when they talk of viability making someone a person. For example:
“The unborn are not persons.”
“Why are they not persons?”
“Because they’re not viable.”
“Why does viability make someone a person?”
“Because they can survive outside the womb.”
“Why does surviving outside the womb make someone a person?”
“Because they’re viable…”
And around you go. This is an example of circular reasoning, but they are begging the question by assuming that viability makes the unborn a person without actually proving it.
If A, then B.
Non sequitur is Latin for “it does not follow.“ If you are committing a non sequitur, then your conclusion does not follow from its premises.
CLICK LIKE IF YOU’RE PRO-LIFE!
A common pro-life non sequitur is that abortion hurts women. Abortion does hurt women, but that doesn’t make it immoral, or mean that it should be illegal. There’s a difference between what’s wrong with abortion and why abortion is wrong. There are many things wrong with abortion, like the fact that it hurts women. But that doesn’t automatically make the practice wrong. For example, cars are dangerous. Many people die in car accidents, but it is not inherently immoral to drive. Abortions do hurt women (and some women die from botched abortions), but that doesn’t make it immoral. It is immoral (and should be illegal) because it unjustly takes the life of an innocent human being.
Another common non sequitur you hear from either side of the debate is “we have aborted X.” A pro-life person will say “abortion is wrong because we’ve aborted the next Beethoven, or the cure for cancer!” But how does it follow that just because we may have aborted someone who would grow up to be great, that abortion should not be allowed. This is a bad argument because the pro-choice person can just retort with “but we’ve also aborted the next Hitler or a serial killer!” It’s a bad argument because the other side can just respond with a hypothetical person we’ve aborted. But it’s still a non sequitur, even if it’s true.
As you can see, there are many ways in which someone might have an error in reasoning. I’ve only just scratched the surface in this article. There are many more, but this should get you started. If you avoid these common pitfalls, your discussions on abortion should be much more productive. In my next article, I’ll cover arguments that are not necessarily logically fallacious, just simply bad arguments.
LifeNews Note: Clinton Wilcox is a member of Secular Pro-Life, where this post originally appeared.