There are certain sequences or developments (cases of one thing following another), which are, in the true sense of the word, reasonable.

They are, in the true sense of the word, necessary.

Such are mathematical and merely logical sequences.

We in fairyland (who are the most reasonable of all creatures) admit that reason and that necessity.

For instance, if the Ugly Sisters are older than Cinderella, it is (in an iron and awful sense) _necessary_ that Cinderella is younger than the Ugly Sisters.