
George Berkeley was an 18th century thinker famous for "to be is to be perceived" and Principles of Human Knowledge, his greatest work.
Irish philosopher and Bishop of Cloyne, George Berkeley (March 12,
1685 – January 14, 1753) is renowned as the father of philosophical
idealism, who showed that the materialism of John Locke and Isaac Newton
was unsustainable. His most famous adage is "esse est percipi" ("to be
is to be perceived").