What is an argument from ignorance?
An argument from ignorance is NOT an argument from someone who is ignorant! Rather, it is a logical fallacy claiming something is true because it has not been proven false, or false because it has not been proven true. Thus, it uses a lack of evidence as evidence itself; this shifts the burden of proof.
For instance, if someone says that there is a fire-breathing cute dragon in their HDB bomb shelter and it is true because no one has disproved it, then we should be suspicious as to whether the entity exists. With such a remarkable claim, the onus is on them to prove it, for they are making a positive claim that something exists; that is, they have the burden of proof. Indeed, whether such a dragon exists should be determinable fairly easily: we can go to the person’s HDB’s flat and open the door to the bomb shelter.
Determining certain other matters is not so easy, especially as it can sometimes be difficult to judge what would satisfactorily count as reasonable evidence for or against. Granted, but the nature of evidence is a different issue in the field of epistemology (our study of knowledge). The argument from ignorance is a fallacy because the absence of evidence (whatever that evidence might need to be) is not evidence of absence; the evidence might become available in the future.
Which of the following would count as arguments from ignorance?:
a). Aliens exist but are hiding from us.
b). The Egyptian God Ra only speaks to me and you cannot disprove it.
c). The Earth is flat; just look around you.
d). I have a pet unicorn who is invisible to any one else except me.
e). That man over there sipping his teh tarik [a frothy hot milk tea] is a self-aware being; just ask him.
Answers: a, b, d
Example c is readily decidable on evidence available to us, such as views from the International Space Station.
Example e is not an argument from ignorance. Here, we have evidence but there may be dispute over what would constitute satisfactory evidence. Just because the man exhibits all the behaviours we expect of a minded person does not necessarily mean he is minded; perhaps he is a highly sophisticated android who can perfectly mimic human behaviour. Within, he is a philosophical zombie. On balance, though, it seems reasonable to presume that he is a minded human being, although our opinion might change if and when certain future technologies are developed.
