How can you get from the sensations of solidity in the mind, to any resembling property in the world? Whatever solidity is ‘in the mind’ it is not the same as solidity in the world. Our ideas are not solid, so what is the sense in saying that they ‘resemble’ solid things? And if solidity disappears from the real world, what is left? Berkeley’s own answer to this is notorious: nothing. His world retreats entirely into the mind—the doctrine known as subjective idealism.
