Emanuel Swedenborg (1688-1772), official * Per Krafft the Elder (1724-1793)

The picture has something of this: portrait, people, elderly, man, writer, jacket, leader, poet, wear, scientist, necklace, facial expression, politician, mustache, retro.
Perhaps it’s a portrait of a man with white hair and a brown coat, holding a book in one hand and writing on a chalkboard in the other hand.