The Philosophy tech unlocks the Mind Bender, a unit that can heal and convert enemies.
The following text will be displayed at the bottom of the research screen once Philosophy has been researched:
Literacy reduces the price of all technologies by 20%!
(Note: The tech costs will be rounded up.)
While in beta, it used to unlock the Library, a building that decreased the costs of technologies, but was scrapped and replaced by the Literacy Bonus.