The enigmatic William of Woking e-mails from London:
Hardly a week passes by without my pondering over your objection to my position on assertion. Would it help us if I try to clarify my position again? And it would help me, if you clarified what your position is. My position is:
2. There is a component of the meaning of the sentence which corresponds to assertion. By this, I mean that without this component, we no longer have a sentence, and by means of this anyone who grasps or understands this component will be correctly taken to be stating what is capable of truth and falsity.
By a sentence you mean a declarative sentence. Such sentences are either true or false. You speak of a component of meaning that corresponds to assertion, a component without which a sentence would not be a sentence. This I don't understand. Which component of 'Tom is tall' corresponds to assertion? It can't be 'Tom' or 'tall.' And it can't be 'is' because 'is' is a syntactic, not a semantic, component.
You may also be conflating the question of what makes a sentence assertible and the question of what makes a sentence a sentence as a opposed to a set, sum, or list of its parts. E.g, what distinguishes the sentence 'Tom runs' (which is either true or false) from the list: Tom, runs (which is neither true nor false)?
If I am given 'Tom is tall' and 'Is Tom tall?' I will classify the first as declarative (indicative) and the second as interrogative. The difference in grammatical mood is indicated by word order and presence/absence of the question mark. But there is no one component in 'Tom is tall' that makes it indicative. So I honestly don't know what you are claiming by (2).
Which of these do you disagree with? Which of them needs further clarification? I suspect you don't agree, for reasons you have given before, namely that the very same sentence can be uttered without the speaker being understood to be stating something true or false (e.g. if the speaker winks, or visibly crosses their fingers, or utters the sentence in an explicitly arch or ironic way).
Right. I made the point that one can utter an indicative sentence and not make an assertion. Suppose Johnny is picking his nose in public, and Mommy says to Johnny, 'We don't do that.' Mommy utters an indicative sentence, and yet does not make an assertion; she issues a command. An assertion is either true or false, a command is neither. If Johnny is a smartass, he might continue picking his nose while saying to his mother, 'You didn't tell me to cease and desist from rhinotillexomania, you merely stated that people like us don't generally engage in it.' You could call that the smartass exploitation of the difference between sentence meaning and speaker's meaning.
I conclude that what makes a sentence indicative and what makes it an assertion are two different things. Indicativity pertains to a sentence-type by itself apart from its tokening by a speaker. Assertion, however, is a speech act and belongs to pragmatics. Furthermore, I do not see that the indicativity of a sentence is signaled by some one separable component of it. Which proper part of 'Tom runs' makes it indcative? No proper part.
A second example. 'Obama sucks' is an indicative sentence. But a tokening of this sentence type will not typically express a proposition or convey an assertion; it will typically be used to express dislike or contempt. So again, whatever it is that make a sentence indicative is different from whatever it is that makes it an assertion.
You have also objected that assertion 'is an act', but I have never clearly understood this objection. I agree that uttering a sentence is an act. But semantics i.e. meaning cannot exist without signs, which are physical and tangible tokens for the thoughts and concepts we want to express. Nor can we express our thoughts (which are personal and subjective events) without the signs. So even if assertion is an act (of producing sign-tokens), that is not inconsistent with what I am claiming. What you need to show is that no physical or verbal or written sign corresponds to assertion. (If that is your objection, but I don't really understand it, as I say).
My point was that assertion is a speech act that belongs within pragmatics, not semantics or syntactics. Perhaps you will grant me that. What you are looking for, apparently, is a part of a sentence that makes it an assertion. But whether or not a sentence is an assertion depends on how it is used in a concrete situation.