Why is "the present king of France is bald" considered false?
- Because "present" means "existing" so it's paradocixal.
- Because the concept of "the present king of France" has no referent.
- Another reason.
Why is "the present king of France is bald" considered false?
Bumble has addressed Russell's reason for treating it this way, the starting point of which is that Russell sees such statements as worth paraphrasing a certain way. Here are three other ways you can interpret the sentence so that it comes out false:
Addendum regarding, "The present king of France is bald," among linguistics students
Since it has been claimed that "any linguist" will tell you that Russell's paraphrase is misguided and contrary to "common sense," I should like to quote the entirety of this answer to a LinguisticsSE question about presupposition failures:
The issue of what happens with a proposition in case of a failed presuppositions is still not settled. There is a huge pile of literature on this matter, so let me just quickly sketch the three main positions, using the classic case of:
(1) The present king of France is bald.
According to Russell, (1) is just false, if the presupposition that there is a present king of France is false. This is still a position that sometimes is maintained (especially for definite description as in (1)), but one must note that this does not really treat the inference that there is a present king of France as a presupposition. Instead it is treated as an entailment.
According to Strawson, a presupposition failure deprives a sentence of it ability to have a truth value. That is, if there is no King of France, (1) is neither true nor false. This often is modeled using a trivalent logic (e.g Beaver & Krahmer 2001), with the values 1 (true), 0 (false), and * (undefined).
According to the “dynamic” view (Stalnaker 1978), a failed preuspposition prevents a sentence from updating the so-called common ground (= the shared belief system of the interlocutors) and may lead to a failed state. That is, if I utter (1) in a conversation, the shared belief system should contain the proposition (or imply it; depending on the formal elaboration) that there is a king of France. If it does, the common ground is updated with the new information that the king of France is bald. If it does not contain the proposition that there is a king of France, (1) will either be unable to update the common ground or it will, but the result will be failed state.
Still the best overview over the historical development of the (technical) of presupposition is provided in the first part of Beaver 2001, which you can access here. A more concise overview (by Beaver & Geurts) can be found in the Stanford Encyclopedia of Philosophy. The Ohio State University also hosts an extensive bibliography on presuppositions.
Beaver, David I. (2001): Presupposition and Assertion in Dynamic Semantics. Stanford: CSLI. http://semanticsarchive.net/Archive/jU1MDVmZ/book-2001.pdf.
Beaver, David I. & Emiel Krahmer (2001): “A partial account of presupposition pro- jection”. Journal of Logic, Language and Information 10.2, 147–182. doi: 10.1023/a: 1008371413822.
Beaver, David I. and Bart Geurts (2011): “Presupposition”. The Stanford Encyclopedia of Philosophy. Winter 2014. http://plato.stanford.edu/archives/win2014/entries/presupposition/
Lewis, David (1979): “Scorekeeping in a language game”. Journal of Philosophical Logic 8, 339–359.
Russell, Bertrand (1905): “On denoting”. Mind 14.56, 479–493. url: http://www.jstor. org.ubproxy.ub.uni- frankfurt.de/stable/2248381.
van der Sandt, Rob (1992): “Presupposition Projection as Anaphora Resolution”. Journal of Semanticsition projection as anaphora resolution 9.4, 333–377. doi: 10.1093/jos/9. 4.333.
Strawson, Peter F. (1950): “On referring”. Mind 59, 320–44.
Stalnaker, Robert (1978): “Assertion”. In: Peter Cole, ed.: Pragmatics. Syntax and Seman- tics 9. New York: Academic Press, 315–332.
Why is "the present king of France is bald" considered false? (if there is no king of France)
It is not generally considered false.
Bertrand Russell's theory of description makes the sentence out to be false, but first his theory is just false, and second, it is not even relevant since it does not try to explain the logic of this sentence, but that of a different sentence, namely, "There is a king of France and he is bald".
It would be false that the king of France is bald if he had hair, but then it would be true that he had hair. In other words, if it was false that the king of France is bald, then it would be true that he is not bald. This is what all proficient speakers in any natural language would say.
Strictly, only consistent statements are subject to logical calculus. Inconsistent propositions become fallacies that can take multiple forms.
Example:
X is true while X is false.
Asking if this is false or true is a false dilemma fallacy. This is a paradox, which is neither false or true.
In case of...
the present king of France is bald
... it fits a fallacy of reification: making further judgements over an inconsistent object. Further judgements in this case (...is bald) produce false dilemmas.
Since it is malformed, the statement is neither false or true.
It depends on what degree of rigour/pedantry you feel inclined to apply. In everyday conversation, you might dismiss the statement as straightforwardly false, on the grounds that if it were true then there would be a bald King of France, and since there is not a bald King of France the statement must be false.
However, the purpose of the example is to highlight subtle inconsistencies and ambiguities in our use language. Someone might point out that to dismiss the statement as being false on the grounds that a king of France does not exist is inconsistent with accepting statements such as 'Sherlock Holmes smokes a pipe' as being true, since Sherlock Holmes is as unreal as the King of France. Others might argue that even where it makes sense to say that a statement is not true, it might not make sense to say it is false, since there is a possibility that the statement is undecidable for some reason. Take, for example, the phrase 'Wednesday violation comparability'- that is neither true nor false because it is not a form of words to which a truth value can be meaningfully applied.
The point is that you can decide to categorise the statement in different ways depending on your purpose.