by Brian Bosse, Copyright June 12, 2010, all rights reserved. 2421 views
There is an important distinction between declarative sentences and propositions. A proposition is simply the meaning of a sentence. So, the distinction between a proposition and a sentence is really the distinction between the sentence and its meaning. That there is a distinction between the meaning of a sentence and the sentence itself is easily illustrated. Consider the following three different sentences:
(1) God is good.
(2) Dios es beuno.
(3) O θεος αγαθος εστιν.
Sentence (2) is a Spanish translation of sentence (1), and sentence (3) is a Greek translation of sentence (1). As such, it is possible for all three of these different sentences to express the same meaning, i.e., they can express the same proposition. Now, consider these two sentences…
(4) You are bad!
(5) You are bad!
Even though these are the same sentences, depending on how they are used they could carry very different meanings. For example, (4) may be a comment on someone’s morality; whereas, (5) could be a comment on someone’s lack of ability in some area. In the right context, (5) could even mean the opposite of a lack of ability. It could be a comment on someone’s prodigious ability. For example, after a very impressive basketball game by Jones, someone might say, “Jones, you are one bad basketball player!” As such, this distinction between a sentence and its proposition is a good distinction - if not an obvious one.
An interesting consequence of this is that sentences do not carry a truth-value. That is to say, that technically, it is improper to say that a sentence is true or false. Only propositions carry truth-value. So, saying something like, “The proposition expressed by sentence (1) is true,” is to use truth-value in its proper context; whereas, to say, “Sentence (1) is true,” would be technically improper.
There are some philosophers (not all!) that see another distinction they call ‘linguistic meaning’ that is different from both propositions and sentences. My next post will explore this distinction.