This is why you’re losing your marbles
The trouble with idiomatic expressions is that they can seem so straightforwardly to refer to real experience that speakers miss their origins in cultural fictions. Consider, for example, the idiom “that dog won’t hunt”, which first appeared in the United States sometime in the 20th century. When language historians deal with the phrase at all, they tend to attribute it directly to the experience of dealing with subpar working dogs. In reality, however, the phrase was carried over from an earlier British idiom, “that cat won’t jump”. Our subject today is a commonplace idiom that speakers tend to interpret, beneath the metaphor, literally, but that actually derives from layers of language loaning and dead metaphor: namely, “Have you lost your marbles?”
The writer Nicholson Baker once wrote an essay about an expression that is almost never heard today, but was remarkably prevalent until the mid-20th century: the word “lumber” as a term for the contents of one’s mind. “The mind has been called a lumber-room, and its contents or its printed products described as lumber, since about 1680,” Baker writes. “Mind-lumber had its golden age in the eighteenth century, became hackneyed by the late nineteenth century, and went away by 1970 or so.”
The metaphor relied on a sense of the word lumber to mean “unused pieces of furniture”. Lumber figured the mind as an attic cluttered with old chairs, old tables, empty trunks, grimy mirrors – the orts and dregs of learning put to no purpose. Thus Boswell praised Dr Johnson’s “continual power of seizing the useful substance of all that he knew, and exhibiting it in a clear and forcible manner: so that knowledge, which we often see to be no better than lumber in men of dull understanding, was, in him, true, evident, and actual wisdom.” Lord Chesterfield sniffed that “Many great readers load their memories without exercising their judgments, and make lumber-rooms of their heads, instead of furnishing them usefully.” As late as 1925, Virginia Woolf could write an essay, titled ‘The Elizabethan Lumber Room’, that took for granted her readers’ understanding of the transitive metaphor from lumber to furniture to knowledge.
As it happens, starting in the mid-19th century, speakers in England were using a flashy new slang word for furniture: “marbles”, which imitates the French meubles, literally furniture. By the time Woolf was writing, Americans were also using the word marbles to mean “wits”, and it seems very likely that the reason for the slang was the longstanding metaphor by which furniture, or lumber, meant knowledge. If you “lose your marbles”, you lose your wits; your birds are flown. The phrase outlived the specialized meanings of marbles and lumber, and even the centuries-old “deep metaphor” that stocked and furnished the mind.
Why did we stop talking in terms of mind-lumber? Baker suggests that the trope had become too clichéd, but another explanation may be that educated people stopped thinking of the mind as a container to be filled (and that could perhaps run out of room). Sherlock Holmes was one of the last self-professed experts on cognitive matters, albeit a fictional one, to live according to this idea: “A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it.” (Later, Holmes solves a case in which the victim was so busy copying out an encyclopedia that he didn’t notice he was being burgled; the lesson, presumably, is that learning everything may distract you from one essential thing.)
As psychology and cognitive science have flourished, researchers have grown ever more confident that learning a new fact does not crowd out old ones, but rather enriches one’s neural pathways. But if there is any truth to the old fancy, we apologize for adding to the inessential lumber in your attic; think of this one as a decorative trinket, a little jar of marbles to brighten a dusty shelf.