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.
Whenever one writes about a literary work, one should employ what is called the "Literary Present." That is, one writes in the present tense, basic form. This use of the present tense is conventional because, although what has happened in the literary work is past, the discussion is current.
So, if one is summarizing a fictional narrative, for example, he/she will use the basic form of Present as well as the basic form of the Present Perfect tense.
For example, if a summary of O. Henry's story "The Gift of the Magi" were being done, one could write, The charming and poignant story of a young couple living in near poverty at the turn of the twentieth century has as its central motif. the true value of love which knows no sacrifice too great for the beloved. The main characters, Della and James Dillingham Young have been married for only a short time, but their love is truly a mature one.
Note that the verbs are in the BASIC PRESENT tense except for have been married, which is in the BASIC PRESENT PERFECT which corresponds to the present and can be used when writing about an action that has occurred before another action. This usage is the "Literary Present."