George Berkeley: Rocks Are Not Physically Real

Bishop George Berkeley

George Berkeley: A Rock Is A Mental Perception. There Is No Matter. Only Mind and Perceptions

George Berkeley (1685 –1753), known as Bishop Berkeley, was an Irish philosopher whose main theory he called "immaterialism" (later referred to as "subjective idealism" by others). This theory denies the existence of material substance and instead contends that familiar objects like tables and chairs are only ideas in the minds of perceivers and, as a result, cannot exist without being perceived.  Berkeley is also known for his critique of abstraction, an important premise in his argument for immaterialism. His famous phrase is  esse is percipi (to be is to be perceived). In other words, we are our sensations, mental events, and the things perceived are not material, but also a form of the mental.

Because he said "Westward wends the course of empire," the city of Berkeley, California, known for The University of California at Berkeley, was named after him.

He wrote Three Dialogues between Hylas and Philonous, which presented his argument.  His views are represented by Philonous (Greek: "lover of mind"), while Hylas (Greek: "matter") embodies the Irish thinker's opponents, in particular John Locke. Berkeley argued against Isaac Newton's doctrine of absolute space, time and motion in De Motu (On Motion), which anticipated the  views of Mach and Einstein.

With his wife, Anne Forster, in 1728 he moved to America to live near Newport, Rhode Island, where he bought a plantation at Middletown, Whitehall. In 1732 he returned to London.

Here is an excerpt from the Three Dialogues:

Hylas to Philonous: You were represented, in last night's conversation, as one who maintained the most extravagant opinion that ever entered into the mind of man, to wit, that there is no such thing as MATERIAL SUBSTANCE in the world.

Philonous: That there is no such thing as what PHILOSOPHERS CALL MATERIAL SUBSTANCE, I am seriously persuaded: but, if I were made to see anything absurd or skeptical in this, I should then have the same reason to renounce this that I imagine I have now to reject the contrary opinion.

Hylas: . . . can anything be more fantastical, more repugnant to Common Sense, or a more manifest piece of Scepticism, than to believe there is no such thing as MATTER?

(First of The Three Dialogues Between Hylas and Philonous, in Opposition to Sceptics and Atheists.)

When James Boswell told Samuel Johnson (1709-1784) about Berkeley's assertion that matter does not exist, Dr Johnson took offense and said, "Sir, I refute it thus!," kicking a rock away from him.

William Fawke Statue
of Dr Johnson
Kicking Stone

Laurance R. Doyle, SETI Institute, has this to say about the world as traditionally physical: ". . . the elementary particles making up the trees, people, and planets—what we see around us—are apparently just distributions of likelihood until they are measured (that is, measured or observed). So much for the Victorian view of solid matter!"

Ronald Knox, English theologian, priest, and crime writer, wrote these limericks, with a mockery and a reply to the mocker of Berkeley:

 Mocker:

There was a young man who said "God

Must find it exceedingly odd

To think that the tree

Should continue to be

When there's no one about in the quad."

Reply:

"Dear Sir: Your astonishment's odd;

I am always about in the quad.

And that's why the tree

Will continue to be

Since observed by, Yours faithfully, God.