Herman Gorter was a Dutch poet and Council Communist theorist. He was a leading member of the Tachtigers, a highly influential group of Dutch writers who worked together in Amsterdam in the 1880s, centered on De Nieuwe Gids.

Ethics, Demonstrated in Geometrical Order, usually known as the Ethics, is a philosophical treatise written in Latin by Baruch Spinoza. It was written between 1661 and 1675 and was first published posthumously in 1677.