I had come to the city of Brno in the Czech Republic—Brünn, as the old Hapsburgs called it—for a conference on the genome and the exposome. How could one resist a meeting on genomics at the Augustinian abbey where Gregor Mendel once kept his peas? It was symbolic even: to return to the monastery where empiricism had worn a monk’s robe.
I had been drifting that way myself for the last few years, toward empiricism. Are we not all on philosophical journeys, wandering from point A to B? Or from point A back to point B? For me, it has been from rationalism to empiricism. After years of thinking of myself as an artist, an armchair philosopher—I found myself drawn to scientists, to their talk of data, their contact with the real. So, in preparation for this pilgrimage, I had packed along An Essay Concerning Human Understanding by the first great empiricist himself, the man who had promised to sweep the mind clean of innate ideas: John Locke.
On the first night after a stimulating reception meeting other conference goers and hearing their—mostly scientific—ideas, I went to bed reading my copy of Locke to find the early world of empiricism.
Instead, I found metaphor.
It began in the first chapter. There was the mind, Locke wrote, “as white paper, void of all characters.” Then the “cabinet,” the “storehouse,” the “impression.” Even this word “impression” which we lazily read as “the real” was a metaphor for a physical imprint. The physical made mental. I had expected the cold precision of observation; I found instead a poet with a carpenter’s soul. His empiricism was built of wood and light and wax—senses reimagined as furnishings of the mind. Ah, the mind! with its lightning speed. “For nimble thought can jump both sea and land, As soon as think the place where he would be,” observed the Bard.
But that’s exactly it. I knew what Shakespeare could do with his philosophies. I’ve known this since I was young. But I now wanted to understand empiricism, to find out whether Locke could point me in its direction.
“The candle that is set up in us shines bright enough,” Locke wrote. But his candle—was it not already a concession to reason? Light, that oldest of metaphors, made experience visible. Empiricism, it seemed, began not with sensation, but with the image of sensation.
I read on, frankly a bit disappointed, but also fascinated to know this writer who was a major part of The Enlightenment, who’s ideas partly shape the creation of the United States of America. For Locke, knowledge became an edifice, a structure built on a foundation. Ideas were “imprinted,” like coins stamped by the mint of nature. Experience was the marketplace where mind and world exchanged their wares. Locke’s England was a mercantile empire, and thought its economic forum, I thought, proud of my phrasing.
But what was I to do with another Shakespeare? Locke’s empiricism was alive with the very metaphors it denied. An anti-Platonic philosophy articulated through a Platonic trope. His cabinet was Plato’s cave, furnished and illuminated.
On the second evening after the sessions, I walked in the abbey gardens, past Mendel’s small greenhouse. The monks had rebuilt it; inside, pea plants climbed the trellis in neat rows. A biologist stood there, naming alleles as Locke might have named ideas. “Dominant, recessive,” he said, almost reverently. These words, too, were metaphors—borrowed from the language of power, not plants.
Then I had my epiphany: empiricism has never escaped metaphor. It cannot. The senses may give us raw material, but language must build the house. Empiricism must borrow from poetry. Locke’s metaphors were not lapses of style; they were his very method, sensory images that made reason empirical.
This did not discourage me. It thrilled me. If Locke, the master empiricist, was already a poet, then philosophy itself might be an art of translation—the constant turning of sensation into figure, figure into sense.
The next morning, I could not concentrate on the slides before me. I did not understand one scientist on the podium after the other, for my brain was whirling with my own discovery, but also with doubts and questions.
You’re confusing rhetoric with reason, I scolded myself. Metaphor is only ornament, not substance.
But how else can one speak of the invisible work of mind except by borrowing from the visible? The empiricist’s problem is that the very thing he studies—experience—is prelinguistic. He must translate the unsayable into figures the mind (or senses?) already know. Metaphor is not decoration; it is the experiment. It is the willingness, the curiosity to translate that new data into forms which already exist, but this time allowing for the new, the variation. The whole idea of metaphor is not A equals B, but that A is similar to B, but beware of the differences. Unlike with the discipline of mathematics, the spark in metaphor comes from the formula of different yet the same—a paradox in math.
We modern readers romanticize Locke, I continued to doubt myself. In his century everyone wrote that way. “White paper” was not poetry; it was pedagogy.
Perhaps. But if empiricism began pedagogically, that too is revealing. The classroom metaphor, the blank slate, the cabinet—all ways of making the student see how knowing happens.
At the break, I strolled again through Mendel’s greenhouse. The peas were maybe a little too neat in their climb toward the roof, their tendrils twisting into question marks. A young professor was discussing the genomic “code.” Philosophers of biology have repeatedly pointed out the “mechanistic” or “machine” metaphor so popular with biologists—none more so than the genome as a computer code. We never stop thinking in borrowed languages. And so what if we do? What was the mechanism of metaphor, to use the machine again. How did it work? And how the heck did empiricism work? Was it literal reception of knowledge from the five senses? Or did it lead us back to rationalism through metaphor?
But wait, why would Locke’s use of metaphor undermine his empiricism? Was I just going down that old rabbit hole of language again? Language is a tool to represent. Why must an empricist always talk literally? Why isn’t the whole panoply of tools open to him? And there I go with the tool metaphor. Was this never to end?
That night, a few of us gathered in a local pub. Perhaps some good Czech Pilsner would give my brain a break from these questions. And it was a fun time. But no! On my walk back to the hotel:
You’re sentimental. Empiricism can use metaphor without being metaphorical. Stop confusing ontology with aesthetics.
But isn’t there always a residue, a trace left by the words and ideas we use? The candle lights the laboratory; its light is still there even if we pretend to work in daylight. If empiricism means describing what we actually experience, then metaphor—the very texture of experience in language—belongs within it.
You’re giving up too soon. Go home. Finish Locke to the end. And then turn to Hume, see how empiricism consumes itself. Then on to Kant, where the forms of intuition restore the structure Locke mistook for experience.
Finally I felt some relief—that which comes from knowing what I will read next. It’s not exactly the satisfaction of answers so much as the satisfaction of better questions and somewhere to go with them. Locke’s cabinet could not stay empty. Yet it was his metaphoric courage—the belief that the mind could picture itself—that made later corrections possible. Without his candle, no critique of pure reason; without his cabinet, no synthetic a priori.
On the night before leaving, I walked once more through the abbey. The lamps in the cloister made yellow pools on the stone. I thought of the chain of metaphors binding Locke to the present: candle to lamp, cabinet to computer, impression to data point. We have never escaped the image; we have only refined its instruments.
Sitting beneath an archway I wrote in my notebook:
Empiricism must borrow from poetry, or it cannot speak.
The senses give material; metaphor gives form.
The experiment begins in language.
I would find a biology conference in Edinburgh early the next year. Hume was waiting for me there with his skepticism, and later I would find, beyond the flicker, some reconciliation in Kant—a philosopher who, like Mendel, believed the mind itself imposed its patterns on the world. But for those few days in Mendel’s garden, I had learned something simpler: empiricism was never merely a method. It was a voice—half scientist, half poet—”casting about” in the dark until the metaphor caught fire.
Now I have begun to suspect that all empiricism needs metaphor—the perception or translation of one idea in terms of another—and all metaphor is experiment. Locke’s cabinet is still with me, not empty at all—full of the furniture of wonder.