
The Mechanics of Life and Thought
From the beginning of written history there has been speculation about
exactly what distinguished living from nonliving things. The distinction
seemed obvious, but hard to put a finger on. Aristotle believed:
What has soul in it differs from what has not, in that the former dis-
plays life...Living, that is, may mean thinking or perception or local
movement and rest, or movement in the sense of nutrition, decay,
and growth...This power of self-nutrition...istheoriginative
power, the possession of which leads us to speak of things as living.
This list of attributes seemed to summarize the qualities of living things,
in ...