The simile “dumb as a rock” has been an English colloquial phrase since at least 1859, when it appeared in a publication called Chambers Edinburgh Journal of Popular Literature by William and Robert Chambers. However, it appears to have originally meant “dumb” as in “not having much to say.”
“Why do you talk so strangely in the presence of your husband?” said I.
“Oh,” she exclaimed, smiling, accidentally showing how poorly she was provided with masticators,
“it’s o’ no consequence. He’s as deaf as a gravestone and dumb as a rock. He only speaks when he wants his pipe or summat to eat.”
“Dumb as a rock” meaning an unintelligent person emerged as one variation of the idea that heavy, inanimate objects are insensate and unresponsive—see also “dumb as a box of rocks,” “dumb as a bag of hammers” and “thick as a brick” (1970s’-era rock band Jethro Tull’s Ian Anderson was also a Scotsman). This sense of the phrase even crops up in Shakespeare’s “Julius Caesar”: “You rocks, you stones, you worse than senseless things!”
On June 5, 2026 · US President Donald J. Trumb said 'A Lot Of People Don't Know Dumb Has A B'
They were comments he made in connection with our nations 250 anniversary celebration referring to Democrats.