At first, it might seem almost impossible that we're able to create and utter such constructions, since they describe impossible scenarios and have no easily identifiable truth value. However when we dive into the complexities of language syntax, we start to find clues that suggest that the truth value composition of our utterances may be more complexly nuanced than they seem on the surface. Take for example the following problem in the philosophy of language (also introduced by Bertrand Russell) involving a reference to a non-existent King of France:
How would you evaluate the truth or falsehood of the following sentence?
"The King of France is bald."
It is important to note that there IS no (current) King of France. Therefore, our instinct (and my forthcoming conclusion) would be to say that the sentence is false. However, what happens when we change it to a negative?:
"The King of France is not bald."
Our inclination would be to again call this sentence false, because there is no King of France to not be bald. In other words, two sentences that are seemingly exact opposites of each other (one being the negation of the other) both possess the same truth value: False.
At first, we might chalk this up to simply calling any sentence with a non-existent subject automatically False. That would be a handy solution. However, what happens when we write this sentence?
"The King of France was bald in 1323."\
King Charles IV (or Charles the Fair), who was King of France in 1323, was indeed bald. The above sentence would be considered by most (including myself) to be a true sentence, despite the fact that there is not currently a King of France for our past-tense utterance to be true about. Therefore, we can't simply say that the lack of a current existing entity to reference automatically renders a sentence false.
Fortunately, all three of our sentences above can have the truth values that we intuitively want to assign to them if we...
- Assume tense of a sentence to surround the rest of the sentence itself
- Assume that we are implying a conjunction:
- The King of France does (or did) exist
- X is or was true of that King of France
… and then the verb to be in each sentence simply takes on the appropriate conjugated form to match the overall tense of the sentence:
"The King of France is bald."
PRESENT → [There is a King of France who is bald.]
False because no such King exists.
"The King of France is not bald."
PRESENT → [There is a King of France who is not bald.]
False because no such King exists.
"The King of France was bald in 1323."
PAST → [There was a King of France in 1323] AND [he was bald]
True because there was a King of France at the time AND he was bald.