George Berkeley was an influential Anglo-Irish philosopher and Anglican clergyman who lived from 1685 to 1753. As a pioneer of the empiricism movement, he is best known for developing immaterialism, a form of subjective idealism which posits that material substances do not exist and that objects are merely collections of ideas perceived by the mind. Throughout his career, he served in several ecclesiastical roles, including Dean of Derry and Bishop of Cloyne, while his philosophical writings deeply impacted subsequent thinkers like David Hume and Immanuel Kant.