This does not call her rationality into question, as she believes the first proposition by being in a belief state properly related to 'Superman is strong' and believes the second by being in a belief state properly related to 'Clark Kent is not strong'.
Alternative proofs could be proposed; for e-conversion, for example, one could argue that "no J is possibly B" converts to "no B is possibly J", if not, then "some B is possibly J", but this with the first proposition produces by Ferio "some J is not possibly J", which is absurd.
The first proposition is implied by the results presented in the previous section.
By the seventh proposition of Book III of the Principia, as we have seen, Newton reached the following conclusion (1999: 810): "Gravity acts on all bodies universally and is proportional to the quantity of matter in each".
In some sense we add the propositions, or at least bits of them: we add the subject of the first proposition to the predicate of the second, aided in this by the middle term.
The first proposition is plainly false.
The first proposition is true, the second arguably true.
The first proposition is included in the list of examples that are undermined by the Evil Genius Doubt (see fourth paragraph of Med. 3).
From these, the first proposition necessarily follows, and every subsequent proposition can be demonstrated using only what precedes it.
According to the first, propositions are a kind of fact.
