Philosophy › Reason, experience & Enlightenment › British empiricism
George Berkeley: to be is to be perceived
1685–1753· Philosopher· Reality, mind & God
Well documentedSolid records, texts or physical evidence.
Irish philosopher and Anglican bishop who argued that material objects exist only as ideas perceived by minds.
See it on the Philosophy map →The idea
Idea: to be is to be perceived (esse est percipi). Reasoning: all we ever know are perceptions, colors, shapes, sounds, textures; the notion of matter existing apart from any mind is empty. So a tree is a collection of ideas, kept in being when no one looks by God, who perceives everything. Main objection: Samuel Johnson kicked a stone and said 'I refute it thus', though that misses the point, since Berkeley never denied stones feel solid.
Why it matters
He pushed empiricism to its logical edge, showing how hard it is to prove a world beyond experience, and set the stage for Hume's deeper skepticism.
Legacy and sources
His Principles of Human Knowledge (1710) and Three Dialogues (1713) survive; Boswell's Life of Johnson (1791) records the stone. The University of California, Berkeley, is named after him.
Still debated
Philosophers still disagree on whether any argument actually refutes his idealism, or whether it is simply rejected as unbelievable.
Connections (2)
▸John Locke was radicalized by George Berkeley: to be is to be perceivedWell documented
The connection
Locke said we perceive ideas, which are caused by material objects we never directly meet. Berkeley pushed the logic further: if we only ever know ideas, the hidden matter behind them is unknowable and unnecessary. So objects just are collections of ideas in minds, ultimately in God's.
When and how
Berkeley, a young fellow of Trinity College Dublin, published his Principles in 1710 and Three Dialogues in 1713, both responding to Locke's Essay.
How we know
Berkeley's Principles names Locke and attacks his 'abstract ideas' and his split between primary qualities (shape, motion) and secondary ones (color, taste).
Debates and open questions
Whether Berkeley read Locke fairly, and whether idealism really follows from Locke's premises, is debated.
▸George Berkeley: to be is to be perceived influenced David HumeWell documented
The connection
Berkeley argued that empiricism undermines belief in matter beyond perception; Hume applied the same test to other ideas, including the self, cause and God. He praised Berkeley's attack on abstract ideas and extended the skepticism, while dropping Berkeley's reliance on God to hold everything together.
When and how
Hume read Berkeley as a young man in Scotland; the Treatise of Human Nature was written in France and published in London in 1739–40.
How we know
The Treatise calls Berkeley's view of abstract ideas one of the 'greatest and most valuable discoveries'; the Enquiry says his arguments 'admit of no answer and produce no conviction'.
Debates and open questions
How closely Hume read Berkeley's other works is unclear; some scholars stress his debts to Malebranche, Bayle or Hutcheson instead.