From Catalus:
To not be contemptuous when a friend makes an accusation — even if it is unreasonable, but rather try to restore him to friendship; to heartily speak well of my teachers (as it is remembered Domitius and Athenodotus); and to truly love my children.

The prior post in this series may be found here

Greek Text and Notes:

Παρὰ Κατούλου τὸ μὴ ὀλιγώρως ἔχειν φίλου αἰτιωμένου τι, κἂν τύχῃ ἀλόγως αἰτιώμενος, ἀλλὰ πειρᾶσθαι καὶ ἀποκαθιστάναι ἐπὶ τὸ σύνηθες: καὶ τὸ περὶ τῶν διδασκάλων ἐκθύμως εὔφημον, οἷα τὰ περὶ Δομιτίου καὶ Ἀθηνοδότου ἀπομνημονευόμενα: καὶ τὸ περὶ τὰ τέκνα ἀληθινῶς ἀγαπητικόν.

Παρὰ Κατούλου

τὸ μὴ ὀλιγώρως ἔχειν
to not lightly esteem, contemptuously hold/have
Again, the section begins with an infinitive.
φίλου αἰτιωμένου τι,
a friend’s imputation, accusation, cause

κἂν τύχῃ ἀλόγως αἰτιώμενος,
even if if by act unreasonably is accusing/imputing

kan: conditional particle
Dative: by an an

a-logos: unreasonably, without reason

ἀλλὰ πειρᾶσθαι
But to attempt/make a trial

The alla marks this clause as the opposite of the preceding clauses.

καὶ ἀποκαθιστάναι
and to restore

The kai coordinates the two infinitives: attempt to restore
ἐπὶ τὸ σύνηθες:
to the dwelling together — hence, friendliness
The epi indicates the goal or result.

καὶ τὸ περὶ τῶν διδασκάλων ἐκθύμως εὔφημον,
and concerning the teachers fully-spirited well-fame

The article indicates possession: one’s teachers
ἐκθύμως εὔφημον: heartily speak well of

οἷα τὰ περὶ Δομιτίου καὶ Ἀθηνοδότου ἀπομνημονευόμενα:

what sort of

τὰ περὶ Δομιτίου καὶ Ἀθηνοδότου ἀπομνημονευόμενα:
The things remembered concerning Domitius and Athenodotus
καὶ τὸ περὶ τὰ τέκνα ἀληθινῶς ἀγαπητικόν.

And concerning the children to truly love
ἀγαπητικόν: adjectival form of agape