Life might be a noun

On the first day of my Metals in Biochemistry class, we discussed two questions: “What is Life?” and “What is Living”? In the first question, Life looks like a noun. In the second question, Living looks like a verb. The students agreed that the second question was easier to tackle than the first, and we proceeded to come up with a range of examples. We also discussed the possible fuzzy boundary between living and non-living – the realm of cyptrobiosis.

 

But maybe, the words life and living should be adjectives. Or maybe it might be instructive to examine the possible interchange of adjectives and nouns. This is what Robert Rosen does in his essay “Genericity as Information”, compiled in his Essays of Life Itself.

 

Rosen is trying to argue that context-independence, a way of slicing up the world into objective chunks, is too impoverished to describe complex systems such as life. By stripping out the subjective, science then “assert that only particular things are real, and that we can learn about them through enumeration of their adjectives.” A corollary to this is that “a set of such particulars is not itself a particular, and accordingly is allowed no such objective reality”. In chemistry, a classification method such as the periodic table is a “subjective intrusion superimposed on the particulars it assorts and classifies”. This is what it means to be a strict empiricist. Rosen is not of this clan.

 

Here’s the example Rosen provides. We can think of particular nouns such as water, oil, and air. The chemist in me is already envisioning particular (pun-intended) pictures of H₂O, hydrocarbon chains, and a box consisting of mainly N₂ and O₂ molecules. Rosen adds that we might classify these three substances as “fluids” for convenience, but the empiricist will emphasize that this is merely for convenience and that “fluid” is not a thing in itself. Rosen then says that the empiricist “has no trouble with phrases such as turbulent water, turbulent oil, and turbulent air. Here, the adjective turbulent correctly modifies a particular noun to which our empiricist will grant an objective status, or reality. But suppose we turn these phrases around, to yield water turbulence, oil turbulence, and air turbulence. We are now treating the turbulence as if it were an objective thing, and the water, oil, and air, as instantiations or adjectives of it.”

 

This interchange of noun and adjective is anathema to the strict empiricist. How can you empirically analyze turbulence in itself? When the famous physicist Erwin Schrodinger asked the question “What is Life?” he implied that it was a particular challenging question that the physics of his era was incapable of answering and that “new” physics was needed. (No, quantum mechanics was not the new physics capable of answering his question.) Perhaps that’s why it’s a little easier to compare a living cat, dead cat, and hibernating cat; and less easy to tackle what it means for a cat to be alive versus a dog to be alive. We sometimes think we can make distinctions: What it means for a bacterium to be alive might be different from what it means for a human to be alive. But it’s hard to grasp what is so distinct about life, not that there aren’t models that have been proposed.

 

The trouble with words is that attaching meaning to them seems inherently subjective. Is there a yawning abyss between syntax and semantics? Is that why describing mechanics in terms of present physics and chemistry doesn’t quite get us to biology? While systems-thinking attempts to bridge some of this gap, is it enough? And if it isn’t enough, then is it true that life cannot truly be simulated in an enclosed system computer or otherwise? Perhaps my efforts as a computational chemist studying the origin of life are doomed from the start.