Reference problem
The reference problem is a problem of philosophical logic . The content of the reference problem are sentences of the type “The capital of Antarctica has 100,000 inhabitants”, the subject of which refers to a non-existent issue. The question is how to deal with these sentences, especially whether they are false or have no truth value at all.
Entailment vs. Presupposition view
There is agreement that such sentences cannot be true if the subject does not exist. What is questionable, however, is the justification for this view and the question of whether the sentence should then be considered false or not have any truth value at all. Bertrand Russell argued that the existence of the subject can be inferred from the use of the subject (the so-called entailment view). For Peter F. Strawson, on the other hand, the existence of the subject was a prerequisite for a meaningful utterance of the sentence (the so-called presupposition conception). Russell interprets the sentence implicitly as "There is a capital city of Antarctica, and it has 100,000 inhabitants", and since in this case the first part of the conjunction is wrong, the sentence takes on the truth value "false". According to Strawson, however, the sentence has no truth value at all. Both opinions are just ways of looking at things that would not lead to different logical conclusions.
Self reference
Another problem that arises because of a particular form of reference can lead to “this sentence is wrong” paradoxes. Here it is a self-reference of the sentence that underlies the problem:
- This sentence is wrong.
or
- This sentence is not decidable .
The same reference problem can also be presented in a more complex way:
- The next sentence is wrong. The previous sentence is true.
Other, but unproblematic self-references are e.g. B.
- This sentence is decidable.
- This sentence is true.