 Ad hominem is a case in point, for there are many instances in which criticisms of an arguer (rather than their position) are a reasonable way to cast doubt on their views. We can specify when this is so by listing critical questions that determine whether this is so in a particular case of argument. The basic question that must be asked is whether there is a good reason why the arguer’s views should not be taken seriously — a question that subsumes the more specific questions whether they have repeatedly shown poor judgment, are biased, lack expertise in the area in question, or are for some other reason an arguer who should not be listened to. 