I quote Swartz:
“What sort of thing is my pen’s being on my desk? We are inclined to say such things as “My pen’s being on my desk is true,” which would suggest that my pen’s being on my desk is a proposition; but we are also inclined to say such things as “My pen’s being on my desk annoyed my wife who was looking for my pen in the bureau drawer,” which, on one reading, would suggest that my pen’s being on my desk is a physical state or an event that has causal consequences. (No proposition has causal consequences; they are not the sorts of things that do.)”[i]
I have a few things to say about meaning, cognitive meaning, propositions, statements, impossibilities and category errors.
Meaningfulness
This predicate applies to statements (in this context). Broadly, if a statement is meaningful that means it is understandable for someone. The someone has to know the correct language (e.g. English), sometimes the context it is used in etc. Consider this example:
E1. KLskjn asdkasdkasdjknjab 2ksdan.
E1 is not meaningful (for me or anyone else). It is also grammatically ill-formed. Note that statements can be meaningless even though they are grammatically well-formed. Consider:
E2. Colorless green ideas sleep furiously.[ii]
So, as we can see this statement does not mean anything but it is grammatically correct. This is because that even though the words are used grammatically correct they do not convey any meaning in the relation they are used in. Philosophers call this a category mistake or category error.
Keep in mind that the meaningfulness I’m concerned about here is in relation to semantics and language, and not, say, actions. Sometimes we say that an action was meaningless, and by that we mean that it had no purpose.
Cognitive meaningfulness
Cognitive meaningfulness is different from meaningfulness itself but it is a proper subset. So, all cognitively meaningful statements are meaningful, but not conversely. A statement is cognitive meaningful iff it conveys a proposition. A statement expresses or conveys a proposition iff it is descriptive. Consider this example:
E3. Go clean the dishes!
E3 is not the kind of statement that describes something, thus it’s not descriptive. And, thus, it is not cognitively meaningful. Some philosophers have thought that moral or ethical statements were statements of this kind, that is, that they didn’t convey propositions. Instead they thought that they had other purposes such as conveying information about the feelings of the speaker, or served as orders.[iii]
Propositions
Propositions are not the statements themselves. No statement is true or false but we usually speak of them like this because it’s easier. Consider this example:
E4. The sky is blue.
E4 is a meaningful statement, and it is a cognitively meaningful statement. Thus, E4 conveys a proposition. It is the proposition that it either true or false.
Meaningless impossibilities?
Consider this example:
E5. There exists a four-sided triangle.
People tend to have different intuitions or opinions about this example. Is it cognitively meaningless? Some think it is. I think it is not. The same people that think it is cognitively meaningless also sometimes think that four-sided triangles are impossible. I contend that these two claims are incompatible in a broad sense.
Recall that if a statement is cognitively meaningless, then it does not convey a proposition. So, I’m curious as to what exactly these people think is impossible. ‘Impossible’ and ‘possible’ are propositional properties, i.e. they are about propositions. But since there is, according to these people, no proposition conveyed by E5 and similar statements, there is nothing relevant that can have the property of being impossible. Perhaps they think that it is the statement itself that is impossible, but this would be a category error. Their position thus implies giving nothing a predicate (or property) or the category error of ascribing ‘impossible’ to a statement.
I contend that E5 conveys a proposition and that that proposition is impossible (and thus false). All triangles have precisely three sides. If a figure has precisely three sides, then it does not have four sides. Thus, the triangle both has four sides and has not. Impossible.
Ambiguity
Consider this example:
E6. He ate the cookies on the couch.[iv]
Suppose we were to assess this statement (i.e. the proposition that it conveys). What are we to make of it? This statement is ambiguous and could mean either of the propositions conveyed by these:
E6a. He ate the cookies that were on the couch.
E6b. He ate the cookies when he was sitting on the couch.
So, an ambiguous statement is a statement that conveys more than one proposition. Usually we use ambiguous language because it is shorter, and the meaning can usually be inferred from the context.
Category errors again
Recall the quote in the beginning of this article. The reason I quoted it was this: In the last part of it Swartz writes that “[n]o proposition has causal consequences”. However, does this make sense? Not really, as much as it does not make sense to say that propositions have causal power, it does not make sense to deny it either. There is no proposition conveyed that can be affirmed or denied. What can be affirmed and denied is that the two words convey a meaning in the relation they are used in. This was what Swartz meant with the second statement “they [i.e. propositions] are not the sorts of things that do”.
We should be very careful when we talk about propositions and meaning. We are inclined to respond “No cars are hungry.” to a person if a person says that his car is hungry, but when we think of it, that statement does not make sense. “My car is hungry” is meaningless and conveys no proposition. Thus, there is nothing we can deny.
We should also not take language completely literal for sometimes people use language non-literally. In the example from above the person might mean that his car needs gas.
An approach to cognitive meaning of statements
It has been suggested that statements are meaningful iff they describe a possible state of the world. But I think this is a bad analysis. First, what kind of possible are we talking about? I will suppose it is logical. Given the thesis above, any statement that describes (more on this) an impossible state of the world is not cognitively meaningful. So, there is no proposition that claims that something is impossible that is true. This is false so the thesis is wrong.
Furthermore, it does not make sense to say that statements describe anything. Propositions describe things. Going by the thesis, if a statement conveys a proposition that describes some impossible statement of world, then the statement is not cognitively meaningful. If the statement is not cognitively meaningful, then it does not convey a proposition, but this contradicts that previous claim that it does, and therefore the thesis is false.
[i] Norman Swartz, The Concept of Physical Law, p. 47, http://www.sfu.ca/philosophy/physical-law
[ii] It is a well known example. http://en.wikipedia.org/wiki/Colorless_green_ideas_sleep_furiously
[iii] http://en.wikipedia.org/wiki/Noncognitivism . See emotivism for the theory about emotions and perscriptivism for the theory about orders.
[iv] Taken from http://en.wikipedia.org/wiki/Ambiguity#Linguistic_forms