"A Treatise Concerning the Principles of Human Knowledge" by George Berkeley is a philosophical work published in 1710. Berkeley challenges John Locke's theories about perception and reality, arguing that the external world consists entirely of ideas rather than material objects. He proposes that existence means being perceived, and that "ideas can only resemble ideas." Through this reasoning, Berkeley rejects the notion of unthinking matter and concludes that a divine force—God—gives the world of ideas its order and regularity. (This is an automatically generated summary.)