Thermostats vs. Amoebae

Intrepid reader Miranda gets right to the bottom of the question, as usual:

I can accept that amoebas and humans share characteristics and that the human form of these characteristics may be more advanced. I can also accept the idea that autonomy may have different layers. But I am not quite sure I understand how what you are referring to as autonomy in the amoeba differs from the "autonomy" of a thermostat. Or can we say that the thermostat also has autonomy and that the amoeba just has more complex autonomy?

My claim is that amoebae are autonomous but thermostats are not.  Hiding right behind Miranda’s question is the twenty dollar one: what do we mean when we say that amoebae are alive but thermostats are not?  Autonomy as an essential element in living organisms is an attempt to get at that question.

The thermostat regulates the temperature in your house but it doesn’t regulate itself.  It doesn’t eat or go potty.  It doesn’t repair itself when it is broken, or have baby thermostats.  To apply Aristotelian functionalism, we could say that not only isn’t it alive but it isn’t even a thermostat unless it is working under the direction of some human being, some person who wants the house to be at a certain temperature. 

Now enlarge the view considerably to include the device, the home dweller, and the manufacturer.  The desire of home dwellers to keep from freezing their butts off and the desire of manufacturers to make money forms a dynamic circuit.  Skipping a lot of intermediaries, we now have a system that brings thermostats into existence and keeps them operating.  This is, if not an example of an autonomous system, at least a very good analogy. 

In the case of the amoeba, the sub-cellular, molecular mechanisms that allow the organism to move and metabolize, are a lot like thermostats.  They regulate all sorts of internal operations but they do not regulate themselves.  They aren’t alive.  But the amoeba is alive because it does regulate itself.  No one outside the amoeba is telling it what to do.  It is reading the rules off of the information embedded in its DNA as well as that embedded in the structure itself and actively applying those rules. 

So no: the difference between a thermostat and an amoeba is not just a matter of increasing complexity, just as the difference between a corpse and a living body is not about complexity, even if in both cases the one is astonishingly more complex than the other.  The difference is a fundamental state of being: one is alive and the other is not. 

Likewise, human beings are more complex than amoebae; but we aren’t any more alive.  So there is a bottom line autonomy that is present in all living organisms, however simple or complex.