Letter to the editor: “Andrea Keene’s selective morality is once again

showing through in her July 15 letter. This time she expresses her abhorrence
of abortion. But how we see only what we choose to see! I wonder
if any of the anti-abortionists have considered the widespread use of
fertility drugs as the moral equivalent of abortion, and, if they have,
why they haven’t come out against them, too. The use of these drugs
frequently results in multiple births, which leads to the death of one
of the infants, often after an agonizing struggle for survival. According
to the rules of the pro-lifers, isn’t this murder?” What kind of fallacy is this and why is it the particular type of fallacy?

The fallacy in the given statement is known as the "tu quoque" fallacy, also known as the "appeal to hypocrisy."

The "tu quoque" fallacy occurs when someone attempts to discredit an argument or position by pointing out hypocrisy or inconsistency on the part of the person making the argument. In this case, the letter writer is attacking Andrea Keene's stance on abortion by accusing her of selective morality and hypocrisy in not speaking out against the use of fertility drugs, which can sometimes result in the death of one of the infants.

However, this argument is a fallacy because it attempts to divert attention from the issue at hand (abortion) by accusing the opponent of inconsistency. Just because someone holds a particular position but doesn't extend that position to a related issue does not necessarily invalidate their argument. In this case, the writer is implying that if Andrea Keene is against abortion, she should also be against fertility drugs. But these are separate issues with different complexities and moral considerations.

It is important to recognize fallacies like this because they can distract from the actual point of the argument and hinder productive discussion or debate. To address such fallacies, it is essential to focus on the arguments and evidence presented rather than getting caught up in personal attacks or attempts to discredit the other person.

I'd call it a red herring fallacy.

http://www.nizkor.org/features/fallacies/red-herring.html