Parts and Wholes

To answer this, let’s conduct a short thought experiment in which we compare a dog and a rock.  A dog is alive; a rock is not.  Both are comprised of matter, but they are essentially different in many ways.  To zero in on just one difference, if the rock were alive like the dog, then food – perhaps in the form of pebbles – would periodically flow into the rock from one side and flow out from the other side as waste.

Moreover, the pebbles would not be just moving through the inside of the rock.  The surface of the rock would also require a steady a flow of “food” pebbles. In fact, the entire rock would be a constant flow of pebbles.  The pebbles would just be parts of the rock temporarily.  They would come and go, but the shape of the rock as a whole would remain the same.  In other words, the matter that comprises the rock would be continuously changing even as its form or shape would generally stay the same over time.

 

If the rock were alive and got larger, or “grew”, its general form would nevertheless remain relatively stable.  We might say that it was “moving” (or growing) while staying in place.

As this thought experiment shows, life is not the same as non-living matter. Life demonstrates the unique ability to maintain its form through a passing change in matter.  In life, parts (which we’ve previously described as “tasks”) are temporary pieces of the same whole.  In a few years, every physical part of the human body is replaced, yet despite this constant process of change, our appearance stays relatively the same over the course of those few years.

Another distinction between a dog and a rock relates to our earlier discussion of parts and wholes.  The rock is made up of parts that are independently wholes.  If we break the rock into two pieces, we have two rocks – not two “half rocks”.

 

The dog on the other hand, is a whole without independent parts.  The ears and the tail are not independently alive. They are part of the overall shape of the dog – a shape that changes over the course of its life, but that nevertheless remains essentially the same.  The water, protein, sugars and minerals that flow through it while it is alive are continuously replenished and replaced. Food, water and oxygen flow in and carbon dioxide and the waste products of metabolism flow out.  Yet throughout all this change, the same dog remains.