Included in the altogether fantastic Alice in Wonderland Cookbook: A Culinary Diversion (public library) — which also gave us some delicious recipes inspired by the Carroll classic and the author’s tips on dining etiquette — is Carroll’s essay titled Feeding the Mind, originally written in 1907, which enlists the power of metaphor to make a prescient case for minding our intellectual diet and aims to make you “see that it is one’s duty no less than one’s interest to ‘read, mark, learn, and inwardly digest’ the good books that fall in your way.”

He begins:

Breakfast, dinner, tea; in extreme cases, breakfast, luncheon, dinner, tea, supper, and a glass of something hot at bedtime. What care we take about feeding the lucky body! Which of us does as much for his mind? And what causes the difference? Is the body so much the more important of the two? By no means: but life depends on the body being fed, whereas we can continue to exist as animals (scarcely[Pg 16] as men) though the mind be utterly starved and neglected. Therefore Nature provides that, in case of serious neglect of the body, such terrible consequences of discomfort and pain shall ensue, as will soon bring us back to a sense of our duty: and some of the functions necessary to life she does for us altogether, leaving us no choice in the matter. It would fare but ill with many of us if we were left to superintend our own digestion and circulation. . . . The consequences of neglecting the body can be clearly seen and felt; and it might be well for some if the mind were equally visible and tangible—if we could take it, say, to the doctor, and have its pulse felt.

In a sentiment Clay Johnson would come to echo more than a century later in his prescription for a healthy information diet, Carroll notes the “painful experience many of us have had in feeding and dosing the body” and proposes that we extrapolate from the rules of food a set of rules for thought taking into account four key factors in what we “consume” intellectually: type, amount, variety, and frequency:

First, then, we should set ourselves to provide for our mind its proper kind of food. We very soon learn what will, and what will not, agree with the body, and find little difficulty in refusing a piece of the tempting pudding or pie which is associated in our memory with that terrible attack of indigestion, and whose very name irresistibly recalls rhubarb and magnesia; but it takes a great many lessons to convince us how indigestible some of our favorite lines of reading are, and again and again we make a meal of the unwholesome novel, sure to be followed by its usual train of low spirits, unwillingness to work, weariness of existence — in fact, by mental nightmare.

Carroll reminds us that non-reading is as much an intellectual choice as reading as he admonishes against the perils of “over-reading”:

Then we should be careful to provide this wholesome food in proper amount. Mental gluttony, or over-reading, is a dangerous propensity, tending to weakness of digestive power, and in some cases to loss of appetite: we know that bread is a good and wholesome food, but who would like to try the experiment of eating two or three loaves at a sitting?

I have heard a physician telling his patient — whose complaint was merely gluttony and want of exercise — that “the earliest symptom of hyper-nutrition is a deposition of adipose tissue,” and no doubt the fine long words greatly consoled the poor man under his increasing load of fat.

I wonder if there is such a thing in nature as a FAT MIND? I really think I have met with one or two: minds which could not keep up with the slowest trot in conversation; could not jump over a logical fence, to save their lives; always got stuck fast in a narrow argument; and, in short, were fit for nothing but to waddle helplessly through the world.

Then, again, though the food be wholesome and in proper amount, we know that we must not consume too many kinds at once. Take the thirsty a quart of beer, or a quart of cider, or even a quart of cold tea, and he will probably thank you (though not so heartily in the last case!). But what think you his feelings would be if you offered him a tray containing a little mug of beer, a little mug of cider, another of cold tea, one of hot tea, one of coffee, one of cocoa, and corresponding vessels of milk, water, brandy-and-water, and butter-milk? The sum total might be a quart, but would it be the same thing to the haymaker?

Having settled the proper kind, amount, and variety of our mental food, it remains that we should be careful to allow proper intervals between meal and meal, and not swallow the food hastily without mastication, so that it may be thoroughly digested; both which rules, for the body, are also applicable at once to the mind.

First, as to the intervals: these are as really necessary as they are for the body, with this difference only, that while the body requires three or four hours’ rest before it is ready for another meal, the mind will in many cases do with three or four minutes.

Here, Carroll turns to a concept we’ve seen articulated by many a famous creator — the power of unconscious processing in productive work, a sort of creative idling the value of which scientists have since proven. French polymath Henri Poincaré ascribed it to the vital workings of the subliminal self and T. S. Eliot argued it allowed for “idea incubation”. Carroll, too, speaks to its power:

I believe that the interval required is much shorter than is generally supposed, and from personal experience, I would recommend anyone, who has to devote several hours together to one subject of thought, to try the effect of such a break, say once an hour, leaving off for five minutes only each time, but taking care to throw the mind absolutely ‘out of gear’ for those five minutes, and to turn it entirely to other subjects. It is astonishing what an amount of impetus and elasticity the mind recovers during those short periods of rest.

He then turns to the “mastication” portion of the process, in which we make sense of what we’ve “ingested,” and stresses the importance of cataloging new ideas via associative trails that affirm connection-making as the key to effective thought:

And then, as to the mastication of the food, the mental process answering to this is simply thinking over what we read. This is a very much greater exertion of mind than the mere passive taking in the contents of our Author. So much greater an exertion is it, that, as Coleridge says, the mind often ‘angrily refuses’ to put itself to such trouble—so much greater, that we are far too apt to neglect it altogether, and go on pouring in fresh food on the top of the undigested masses already lying there, till the unfortunate mind is fairly swamped under the flood. But the greater the exertion the more valuable, we may be sure, is the effect. One hour of steady thinking over a subject (a solitary walk is as good an opportunity for the process as any other) is worth two or three of reading only. And just consider another effect of this thorough digestion of the books we read; I mean the arranging and ‘ticketing,’ so to speak, of the subjects in our minds, so that we can readily refer to them when we want them.

This “bundling” and “ticketing” of information, rather than its mere retainment and rote memorization, is what Carroll believes distinguishes the truly knowledgeable from the flatly “well-read” — or, to use wholly different metaphor, the dynamic library from the static storage facility:

You turn to the thoroughly well-read man. You ask him a question, say, in English history. . . . He smiles good-naturedly, tries to look as if he knew all about it, and proceeds to dive into his mind for the answer. Up comes a handful of very promising facts, but on examination they turn out to belong to the wrong century, and are pitched in again. A second haul brings up a fact much more like the real thing, but, unfortunately, along with it comes a tangle of other things—a fact in political economy, a rule in arithmetic, the ages of his brother’s children, and a stanza of Gray’s ‘Elegy,’ and among all these, the fact he wants has got hopelessly twisted up and entangled. Meanwhile, every one is waiting for his reply, and, as the silence is getting more and more awkward, our well-read friend has to stammer out some half-answer at last, not nearly so clear or so satisfactory as an ordinary schoolboy would have given. And all this for want of making up his knowledge into proper bundles and ticketing them.

Carroll ends with an entertaining “test” for healthy mental digestion:

To ascertain the healthiness of the mental appetite of a human animal, place in its hands a short, well-written, but not exciting treatise on some popular subject — a mental bun, in fact. If it is read with eager interest and perfect attention, and if the reader can answer questions on the subject afterwards, the mind is in first-rate working order. If it be politely laid down again, or perhaps lounged over for a few minutes, and then, ‘I can’t read this stupid book! Would you hand me the second volume of “The Mysterious Murder”?’ you may be equally sure that there is something wrong in the mental digestion.

Follow this feast with a delicious dessert of Carroll’s heartily amusing letter of apology for standing a young friend up, then revisit Henry Miller on reading and Virginia Woolf on how to devour a book.

Thanks, Kaye!