Gerundive Confusion

Question

North & Hillard Ex. 196: the following is to be translated into Latin: "He (Hannibal) had almost reached the top of the Alps, when some old men came to him in the guise of envoys. The misfortunes of others, they said, had been a warning to them, and they preferred to make trial of the friendship rather than the might of the Carthaginians, and were ready to do whatever he wished. Hannibal, considering that he must not rashly either trust or slight them, accepted them as guides,"

The tricky part (Answer Book): "...quos Hannibal duces quidem accepit (accepted those who are guides, the English requires "as guides"-ducendos?), neque iis a se temere credendum ratus neque omnino asperandos eos esse;".

The narrator is reporting what the fake envoys said to Hannibal—indirect speech requiring the acc.-infin. construction for the indirect statement: "omnino aspernandos eos esse"—they had not to be offended at all. The preceding gerundive is given differently—neuter, impersonal "credendum"; not, "credendum est"—is this permissible, omitting "est"? Presumably, given that credo takes dative, dative-plural "iis" must be deployed (for them to be believed). In the acc.-inf. credendos eos esse—"eos" would clash with "iis".

Is this why the impersonal construction has been used?

In all the examples I have found on this, "est" has been deployed eg.

"mihi currendum est"—I must run (it ought to be run by me);

"Romanis cum hostibus pugnandum est"—the Romans ought to fight with the enemy (it ought to be fought, by the Romans, with the enemy).

Initially, thought that these were gerundives-of-obligation; but, that would have needed Hannibal to go into the dative, Hannibali, as the person upon whom the obligations were falling--neither for him (a se) to be believing nor offending.

Answer 1

A basic problem here is that trust or belief works with dative in Latin. For example:

Tibi credo.
I trust you.

One can express obligation with gerunds, putting the subject (implicit ego) into dative:

Mihi tibi credendum est.
I have to trust you.

But given the flexible word order, which one of mihi and tibi is supposed to be the subject and which one the object of trusting? To clear the ambiguity, one can use an agent instead of the dative:

A me tibi credendum est.
I have to trust you.

Now the roles are clear. This is how something like iis ab Hannibale credendum est appears in the suggested translation. The obligation is personal, but the obliged person is now unusually expressed with agent instead of dative.

We have thus arrived at the translation:

He must not trust them.
Ab eo non iis credendum est.

Now, we build up from this, introducing this as Hannibal's thoughts:

Hannibal thinks that he must not trust them.
Hannibal retur a se non iis credendum esse.

The previous translation turns from direct speech to ACI, and the pronoun referring to Hannibal (eo) becomes reflexive (se). There is indeed a missing verb, but it is esse instead of est because we are within an ACI. To avoid repeat, the same esse is used for the two obligations.

To take a step further, Hannibal makes a choice based on these thoughts:

Thinking that he must not trust them, Hannibal accepts them.
Hannibal, ratus a se non iis credendum esse, eos accipit.

The personal verb retur becomes a participle ratus, an attribute to the subject Hannibal of the new main verb accipit. This already has most of the structure that confused you.

I very, very warmly recommend slowly building a sentence up like this. There is no need to understand the whole structure in one go; strip everything unnecessary and start adding layers to get closer to what you want. Similarly, when analyzing a Latin sentence, try to identify the key component and throw the rest out. It also helps you identify the issue and ask for help that clears the key confusion.

A couple of things need explanation. The relative pronoun can be used to refer to people mentioned in the previous sentence. You should understand here quos as eos. Consider, for example:

Quidam amicus meus Romae vivit. Qui cum mecum loquitur, gaudeo.
A friend of mine lives in Rome. When he speaks with me, I am happy.

To accept X as Y, you X Y accipis, with both X and Y in accusative. For example,

Te ducem accipio.
I accept you as a guide.

This is essentially what happens in the suggested translation. The one being accepted is quos, meaning "they". That is, the translation is:

Quos Hannibal duces accepit.
Hannibal accepted those who are guides.
Hannibal accepted them as guides.

I hope this analysis makes things clearer.