Why "inscripserim" and not "inscripsi" in Haury's translation of "Le Petit Prince"?

Question

Haury's translation of the dedication of "Le Petit Prince" begins like this:

Pueros oro ut mihi ignoscant quod librum hunc ad adultum hominem inscripserim.

I don't get why we have a subjunctive in the causal clause since in Allen and Greenough's Latin Grammar, one can read:

The Causal particles quod and quia take the indicative, when the reason is given on the authority of the writer or speaker; the subjunctive, when the reason is given on the authority of another.

I would have expected:

Pueros oro ut mihi ignoscant quod librum hunc ad adultum hominem inscripsi.

Answer 1

This quod is best seen as a relative pronoun with implicit antecedent, or perhaps as a conjunction "that", not "because": "I beg children to forgive me for the fact that I have dedicated this book to an adult man".

I believe finite clauses dependent on indirect speech are often, but not necessarily, in the subjunctive: I think I once wrote a little paper about this, concluding, "it varies", I think by period, but even within the work of the same author. The conjunction ut can be said to introduce indirect speech here, and the quod clause depends upon it. So I am not too surprised to see the subjunctive.

Brian has given an example in the comments above that seems similar, with the subjunctive, by Plautus:

obsecro te...ut...mihi...ignoscas quod animi impos vini vitio fecerim. — Plautus, Truculentus 4.3.54.

There is also this example from Cicero, with the indicative:

velim mihi ignoscas, quod ad te scribo tam multa toties" — Cicero, Ad Atticum, VII.12.3.