In which tense should a summary on a literary work be written?

Here is an except from a paper I wrote. Present tense for quotations or summaries, but when you describe actions that took place, you put that into the past.

The Romans were unapologetically religious. Indeed, if one trusts the ancient sources, the Romans were famous for, or better yet, made famous by, their piety towards the gods. For example, Cicero succinctly says “we have surpassed every peoples and nation in piety, religious issues and that singular wisdom, because we realize that everything is ruled and controlled by the will of the gods.” Even opposing interlocutors of a dialogue agree on one point, namely, the connection between Roman religiosity and divine favor. The Stoic, Balbus, in Cicero’s De Natura Deorum, says, “If we wish to compare our [republic] to others, we will discover that in other things we are equal or inferior, but in religion, namely, the worship of the gods we are far superior.” Cotta, his Academic critic, does one better. “I have always considered that no religious matter ought to be despised and I am persuaded that Romulus by auspices and Numa by sacred rites established the foundation of our city, which could have never been as great as it is without the greatest favor of the gods.” Vergil, a generation later, reiterates this same sentiment as he has Jupiter declare that he has given the Romans an empire without end.