In particular, he says that Ex Falso is unacceptable for the reason that it asserts something about the consequences of something impossible (van Heijenoort 1967, 421).
A rule-circular argument, by contrast, is an argument of which the conclusion asserts something about an inferential rule that is used in the very same argument.
A statement consists minimally of two parts, with one part (the grammatical subject) referring to the entity the statement is about, and the other (the predicate) asserting something about that entity.
They assert something interesting, something paradoxical, something strange or funny, and then compel us to complete their thought.
The critic insists that to assert something one must believe it.
Before mathematicians assert something (other than an axiom) they are supposed to have proved it true.
For instance, when the Stranger says of Theaetetus, who is currently sitting, "Theaetetus is sitting," his statement is true because it asserts something that is the case about Theaetetus; but when he says of Theaetetus (still sitting), "Theaetetus is flying," his statement is false, because "flying" specifies something different from what is the case about Theaetetus (namely, sitting).
David Donald asserts something like the opposite in his biography: "At about the time of Willie's death Lincoln's optimism about military affairs also began to vanish".
All of which is further evidence for the wisdom in that line from Hamlet about the lady protesting too much: strenuously asserting something is often a sign that, really, you doubt it, or believe the opposite.
By contrast, one who asserts something she does not believe to be true has lied.
