The River of Ideas
Portrait of George Berkeley by John Smibert

Early Modern · 1685–1753

Berkeley

Does anything exist if no one perceives it?


George Berkeley took empiricism to a startling conclusion. If all we ever experience are ideas and sensations in our mind, he argued, then maybe that's all that exists — ideas! For Berkeley, ‘to be is to be perceived.’ Things don't vanish when you stop looking, he said, only because God is always perceiving everything.

To be is to be perceived.
George Berkeley

The big idea

Berkeley was an ‘idealist’: he denied that matter exists independently of minds. All that exists, he said, are minds and the ideas they perceive. The world stays stable and shared because it exists as ideas in the mind of God, who perceives everything at all times.

What they changed

He pushed the logic of empiricism to its limit, forcing philosophers to take seriously how mind relates to the physical world. His challenge — ‘prove that matter exists outside your mind!’ — is still a classic philosophy puzzle.

The controversy

Most people find it wildly counterintuitive that a chair stops being solid ‘matter’ the moment no one perceives it. The writer Samuel Johnson famously ‘refuted’ Berkeley by kicking a stone — though kicking it only proves you perceive it, which is exactly Berkeley's point.

In their words

✦ A curious detail

The city of Berkeley, California — and its famous university — are named after him.

Read further

Portrait: Portrait of George Berkeley by John Smibert. Public domain · via Wikimedia Commons.

Meet Berkeley on the voyage

A curated lecture, a short enquiry, and a wax-seal medallion to acquire — and the next thinker unlocks. No account, no password.

Begin the voyage

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