[p 10:] As we have seen, an argument is a piece of reasoning in which one or more statements are offered as support for some Other statement. If a piece of writing makes a claim but gives no such reasons for us to believe it. it is not an argument. Likewise, a passage that makes no assertion at all is not an argument. [1.] Thus, questions are not arguments, nor are announcements, complaints, compliments, or apologies. Such passages are not arguments because, again, they make no effort to persuade us. [End of 1.]
[p 11:] More difficult are those cases in which reasons are indeed offered but more in way of clarification rather than justification. Although appearing like arguments, such passages are often no more than a collection of statements, one expanding on the other.
[p 12:] And that is perhaps another way in which we might distinguish passages whose main purpose is to explain rather than convince: an explanation takes that is considered and a fact and tries to clarify it further; an argument takes something not generally known or yet agreed upon and tries to establish that it is a fact. An explanation, that is to say, begins with the assumption that a certain statement is true and attempts to elaborate on what its author means, precisely, to assert. An argument attempts to establish that the statement in question is true by offering supporting reasons or it.
How is 1 always true? What if an announcement, complaint, compliment, or expression of sorriness asserts (i.e. propounds supporting reasons) to establish itself true?