(, , or ; Greek: , from λέγω lego "I say") is an important term in western philosophy, psychology, rhetoric, and religion. It is a Greek word meaning "a ground", "a plea", "an opinion", "an expectation", "word", "speech", "account", "to reason", but it became a technical term in philosophy beginning with Heraclitus (ca. 535–475 BC), who used the term for a principle of order and knowledge.

LOGOS cards is a collectible card game developed for Second Life. The game was first conceptualized by Florian Kraner in 2008. Development began in earnest early 2009 with the addition of Darien Caldwell to the creative team. The full game was released on July 1, 2010.