A dramatist is one who believes that the pure event, an action involving human beings, is more arresting than any comment that can be made upon it. On the stage it is always now; the personages are standing on that razor edge, between the past and the future, which is the essential character of conscious being; the words are rising to their lips in immediate spontaneity. […] The theater is supremely fitted to say: “Behold! These things are.”

Thornton Wilder (1897-1975) American novelist and playwright
“The Art of Fiction No. 16,” interview by Richard H. Goldstone, The Paris Review (1956, Winter)
    (Source)

Collected in Jackson Bryer, ed., Conversations with Thornton Wilder (1992).