Short answers, pulled from the story.
Jean-Baptiste Say entered the world on the 5th of January 1767 in the city of Lyon. His father Jean-Etienne Say came from a Protestant family that had moved from Nîmes to Geneva after the revocation of the Edict of Nantes.
The year 1803 brought his principal work titled Traité d'économie politique. This text contains his famous concept that products are paid for with products rather than the phrase supply creates its own demand coined by John Maynard Keynes.
Napoleon removed Say from his tribune position in 1804 because he refused to compromise his convictions for political gain. He resigned his editorship of the Decade upon taking this political office earlier in 1799.
Entrepreneurs act as intermediaries who combine productive agents such as land, capital and labor to meet consumer demand. They play a central role in the economy by fulfilling a coordinating function while possessing judgment and unerring market sense.
In 1831 he received the title of professor of political economy at the Collège de France. A chair of industrial economy had been established for him in 1819 at the Conservatoire des Arts et Métiers prior to this appointment.