IV. Extended uses.
IV.7. Of a person: having a lively, volatile, or restless nature;
liable to sudden and unpredictable changes of mind or mood;
quick-witted, imaginative.
Later also gen. (applied to animals, phenomena, etc.,):
changeable, unpredictable, fickle.
Oxford English Dictionary
A word over-steeped in our collective history and under-utilized in our collective vocabularies. Mercurial has thirteen definitions as both a noun and an adjective that range wildly from one another. The earliest use of the term was as a noun for the family of plants that bear the name, but that use has been out of style for centuries. The earliest we would actually recognize is in relation to the planet. A subsection of this term bloomed forth through astrology, in which the influence of the planet is taken into account for divinatory practices. Not long after the word made its switch from plant to planet, the adjective also began to be used to describe anything affiliated with the Roman god of commerce, eloquence, and travelers.
And yet none of this history closely relates to how we use the word now. For that we must briefly discuss alchemy. The loose progenitor of chemistry, alchemy was concerned with transformation—particularly with metals. A field of study peculiarly connected to our contemporary usage of this word. Both are concerned with change. In alchemy, the most notable metals were commonly associated with the planets, and quicksilver was tied to the fastest of the planets: Mercury. The modern scientific name for the chemical element Hg comes from this aged association.
It is this metal that gives mercurial its most commonplace usage in the twenty-first century. Mercury, with its low melting point, is associated with liquid. Which itself is commonly associated with change. Since mercury cannot hold its solid shape, it is seen as fickle.
Unstable.
Erratic.
Mercurial.
Yet in all this one thing can be certain: this musing cannot fully encapsulate what mercurial means. Nor can the precise interpretations of the Oxford English Dictionary, as it deftly dissects the fuzzy intersections between motes of meaning into a definitive list of thirteen uses.
In the end, all words are mercurial, messy things that cannot be contained in boxes by margins. In this very essay the words meld into each other as tiny symbols and allegories that no single word could achieve alone.
To pluck a word out of context and bring it under the scalpel is a fool’s errand. In every lone noun, verb, and adjective there is a multitude of mercurial undertones and overtones. Two words, I might add, that have separate definitions but one shared commonality: they are both used to describe hints of something beyond the surface.
This, of course, extends beyond the page. People, like words, cannot be cut up and dissected into four easily understood humors, temperaments, or elements. There are not nine nor twelve nor sixteen easily defined crates we can be plunked in. Archetypes attempt to rein in order onto the mercurial adumbrations that make humanity an unceasing engine of interest to all of us. No one escapes the birthmark of uniqueness, stamped red-hot onto our skin by a solitary mixture of DNA, circumstance, and free will.
But disorder is an impossible thing to truly accept. After all, we are soaked in the unrelenting water of order in every direction. The very atoms that work together to read this phrase. The ecosystems that have molded themselves to every crevice of the earth. The enormous, molten spheres of matter that twirl ever-further from each other. None of this is entropy, it is plain to see.
And so we are left with the uncomfortable conundrum of two impossible truths that need to coincide. Leaving us with an uncomfortable bathos as we consider what everything means. That push and pull of order and disorder. Both equally cogent. Both equally unsatisfying. But that's just it. They cannot make sense alone, but together there emerges some sort of explanation.
Life, it appears, is mercurial.
To talk philosophically of the meaning of life, the universe, everything is a good way to go mad. So let's take a step forward and remain more grounded. Mercurial in the modern lexicon is used most commonly in academic circles to describe something that easy to change. This, of course, makes sense in reference to the element that remains liquid in an average room temperature. Already I've touched on circumstance and how important it is to what makes up a person. Nurture, as opposed to nature, cannot be understated. We are all mercurial in the sense that we can change a great deal. That change can occur slowly or quickly. From one finite event or from the sands of time. Take, for instance, the way that we are all constantly replacing dead cells with new ones. Scientists estimate that every seven years a human being has replaced every cell in their body. Like the ship of Theseus, we exist, but not as the same person we were. Our memories remain, even if they are contorted, funhouse mirrors of our initial experience. And yet if we go back far enough, none of the cells that make us up were actually present for those experiences.
But all this is speaking in a vacuum. We on earth (so far as we can tell) are uniquely lucky to not live in a vacuum. We are surrounded by atmosphere, plants, animals, and people. People who have their own solitary mixture of DNA, circumstance, and free will. And when people collide, life gets ever more mercurial.