According to a recent science article at the Huffington Post, Sara Walker, an astrobiologist at Arizona State University, along with some of her colleagues, has arrived at a fresh definition of life as seen through the prism of information processing:
Walker’s team created a simple mathematical model to capture the transition from a nonliving to a living-breathing being. According to the researchers, all living things have one property that inanimate objects don’t: Information flows in two directions.
For instance, when a person touches a hot stove, the molecules in his hand sense heat, transmit that information to the brain, and the brain then tells the molecules of the hand to move. Such two-way information flow governs the behavior of simple and complex life forms alike, from the tiniest bacteria to the giant humpback whale. By contrast, if you put a cookie on the stove, the heat may burn the cookie, but the treat won’t do anything to respond.
Another hallmark of living beings is that they have different physical locations for storing and reading information. For instance, the alphabet of letters in DNA carries the instructions for life, but another part of the cell, called the ribosome, must translate those instructions into actions inside the cell, […]
The new model […] lays out the behavior needed for a system […] to be considered living, Walker said.
I like this definition a lot, and would put it in my own words this way: life is a gatekeeper; it means saying ‘yes’ and ‘no’ to things. To indiscriminately go with the flow means death. Flow must stop, be evaluated, and sometimes get sent back, via force, to where it came from. That’s life and power–the will to power. Yes, I’m thinking of Nietzsche here.
But I’m also thinking of President Obama. Life is a president with veto powers. The buck stops at its desk, its bar. Stimuli, like bills from Congress, receive evaluation and response. They get ping-ponged back to where they came from if the president reads them and doesn’t like them, or they are dealt with in some other way (as when a president sets forward his hand to sign a bill). In either case, information is received by life, processed, moved about among its “staffers” (synapses, protein machines, ribosomes, etc.), and acted upon.
Here’s another metaphor. If going with the flow means death, life is “a river that flows uphill.” You don’t defy entropy (the river flowing downhill) without some DNA, some blueprint, some plan, some information processing. That information processing runs on energy, so you’ve got to capture energy, store it, and enlist it in the communication and carrying out of your plan. That’s what it means to be alive: to defy entropy; to move information about so as to put your plan in effect with the energy you’ve managed to corral.
Here’s yet another metaphor. Life, like Iago in Othello, reads its situation, puts its ducks in a row, and acts.
Here’s still another way to put it: life receives (notices) messages, interprets them, and sends them back or otherwise reacts to them from an interested vantage. By an “interested vantage,” I mean the one that concerns you, as to your own curiosity, desire, aversion, preservation, or growth.
You may also be given over to the concerns of another. That too is life. But now I’m thinking of Hegel’s Master-Slave dialectic. Life is Master to its own purposes or Slave to other purposes–the purposes of some more complexly organized, stronger, or greater life (as when the ribosome, as part of the larger cell’s “team,” reads off the DNA, translates it, and sends that information off and into the service of making protein machines for that team’s greater good).
A living thing, in short, is always identifiable and situated in time and space–not nowhere, but somewhere, and it’s always seeking to increase its range; its power. If it’s not doing this, it’s being enlisted into the service of some other power. But so long as it is alive, it is motivated, interested. It has some interest at stake (its own or that of a greater life).
And this brings us to the definition of consciousness. Like life, consciousness too is a gatekeeper; a locus for attention, discrimination, translation, interpretation, judgment. It arrests the flow of habit and says ‘yes’ and ‘no’ to things. It’s selective; both a witness and an actor. Attentive to the theatre of passing forms, it has preferences. It receives and sends information, makes plans, and executes them.
Consciousness, in other words, is also a river that flows uphill, dependent on capturing and using the body’s stores of energy against the easy entropic dissipations of nondiscrimination, habit, instinct, and sleep. Maintaining conscious attention and purpose, like maintaining life, is work. Work against entropy. And like life, consciousness can associate itself with narrow boundaries or expansive ones, with competition or cooperation. Consciousness, as it were, is spiritual life; a realm of selfish memes, not genes; of qualia, not unconscious and mechanical stimuli and responses.
Consciousness sometimes (often?) functions as a counterlife to your long evolved instincts, checking them, vetoing their impulses. It’s as if, being both a conscious being and a biological being, that you are a mini-Congress; a divided government. That’s interesting, isn’t it?
David Goodsell, a molecular biologist at The Scripps Research Institute in California, in his introductory text to molecular biology, The Machinery of Life (2nd edition, Springer 2010), which Scientific American calls “an impressive and original book,” offers the following definition of life (29):
In 1944, the physicist Erwin Schrödinger presented a very simple definition of life that has withstood the test of time. He identified one property that all life shares: living things avoid decay into equilibrium.
I like this, but it sounds a bit conservative to me. Life, after all, isn’t just about checking the flow of energy to make sure it isn’t causing the status quo to fall apart. It’s also about growth and expanding power (and yes, I’m back to Nietzsche again). A DNA program’s mission is biased to expansion; to exploiting resources wherever possible; for getting what it wants. It is not merely in the business of survival. Grow or die.
I suppose this post has been a kind of sermon to my soul (and to any soul that made it this far with me). So I’ll wrap it up like a preacher, pointing to a bit of verse. This is the opening couplet to W. H. Davies’ poem, “Leisure” (1911):
What is this life if, full of care,
We have no time to stand and stare?
I read the poet’s provocation this way: sometimes you should use your veto powers; sometime the life of consciousness checks the urgent missions of its biological life, preferring visual pleasure–the aesthetic consciousness–to the urgent and evolved agendas of the instinctual organism. Consciousness is a life form that frequently hijacks the body’s mission of growth and survival to other purposes (or tries to). This makes for the dance–sometimes harmonious, sometimes not–of will and instinct (Nietzsche yet again).
This is life. The buck stops with you. How will you fashion and command, and to what purpose?