Read the passage. the africans transplanted to saint domingue remain in general indolent and idle, quarrelsome and talkative, and liars, and are addicted to stealing. always given to the most absurd superstitions, there is nothing which does not frighten them more or less. — a civilization that perished: the last years of white colonial rule in haiti, 1797 the passage shows that the author was most likely someone who was

A European who supported slavery.

The author of that book was Médéric Louis Élie Moreau de Saint-Méry (1750-1819), a French lawyer and writer who also had a political career.  He was a slave owner and did not believe the "rights of man" as embodied in the French Revolution applied to blacks.  He even wrote about racial theories, looking down on whites intermarrying with blacks in the French colony of Saint-Domingue (which is now Haiti).