In summaries, keep to one tense.
In summarizing the action of a drama, the writer should always use the present tense. In summarizing a poem, story, or novel, he should preferably use the present, though he may use the past if he prefers. If the summary is in the present tense, antecedent action should be expressed by the perfect; if in the past, by the past perfect.
An unforeseen chance prevents Friar John from delivering Friar Lawrence’s letter to Romeo. Meanwhile, owing to her father’s arbitrary change of the day set for her wedding, Juliet has been compelled to drink the potion on Tuesday night, with the result that Balthasar informs Romeo of her supposed death before Friar Lawrence learns of the non-delivery of the letter.
But whichever tense be used in the summary, a past tense in indirect discourse or in indirect question remains unchanged.
The Friar confesses that it was he who married them.
Apart from the exceptions noted, whichever tense the writer chooses, he should use throughout. Shifting from one tense to the other gives the appearance of uncertainty and irresolution.
In presenting the statements or the thought of some one else, as in summarizing an essay or reporting a speech, the writer should avoid intercalating such expressions as “he said,” “he stated,” “the speaker added,” “the speaker then went on to say,” “the author also thinks,” or the like. He should indicate clearly at the outset, once for all, that what follows is summary, and then waste no words in repeating the notification.
In notebooks, in newspapers, in handbooks of literature, summaries of one kind or another may be indispensable, and for children in primary schools it is a useful exercise to retell a story in their own words. But in the criticism or interpretation of literature the writer should be careful to avoid dropping into summary. He may find it necessary to devote one or two sentences to indicating the subject, or the opening situation, of the work he is discussing; he may cite numerous details to illustrate its qualities. But he should aim to write an orderly discussion supported by evidence, not a summary with occasional comment. Similarly, if the scope of his discussion includes a number of works, he will as a rule do better not to take them up singly in chronological order, but to aim from the beginning at establishing general conclusions.