How many letters does the top answer for “wrote the art of loving” have?

The most common answer is fromm (5 letters).

Crossword clue: wrote the art of loving

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

fromm 5 letters wd-fact-v3

author of the art of loving 50% similar → fromm

wrote the art of war 50% similar → tzu