I would break down the question of life into two parts: first, the
question of what is life in relation to how life came to be and how it
changes over time. This definition of life would consider an individual
living organism in the context of its ancestors and descendants. In
this context, the ability to replicate or reproduce a living organism
would be an essential element for what it means to be alive.
A second part for considering the definition of life would be a more
limited one, in which we might ask, what does it mean for an individual
organism to be alive, independent from its ability to reproduce. For
such a definition, one could propose that to be alive includes the
ability to take in energy and material building blocks, and to be able
to autonomously construct, maintain and repair all of the component
parts of the organism. This is a rather general definition of life and
I would be interested in the opinion of others about what limitations
this definition might have, and to hear other definitions that may
provide different insights into the question.
Later, Jake