when does chemistry become more than the sum of its parts?”

This evening I’ve read, in rather close succession, two very interesting lines.

The second was the one I just quoted above.  It comes from a BBC article titled: “There are over 100 definitions for life and all are wrong!

A little earlier I had come across Confucius’ “When it is obvious that the goals cannot be reached, don’t adjust the goals, adjust the action steps.

I could not resist the temptation to put these two together.

Rather than defining ‘life’ I’ll try to see what obviously (?!?) differentiates ‘living creatures’ from ‘chemically driven’ systems.

Inside/outside.

Life is about individuals. Huge, small, whatever. But each of them are individual beings.
Each of them, including the viruses, have a ‘membrane’ which separates ‘inside’ from outside and the survival of each individual depends on this membrane being able to do it’s job.

Chemical systems also have separations that ‘contain’ them into an ‘inside’ only those separations are not, in any way, controlled by the system itself as it happens with the membranes that separate the living individuals from their environment.

Lineage

While life is about individuals, it’s also about ‘species’.
If you remember, Darwin’s seminal book was entitled “On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life“.

Species are nothing but ‘lineages’ of slightly different individuals who somehow manage to pass from one generation to another enough ‘structural’ (genetic) information so that the species remains ‘consistent’ but, simultaneously, the ‘replication process’ is flexible enough to allow for enough ‘mutations’ – which constitute the engine of evolution. The process is very well explained here: “What Evolution is” by Ernst Mayr.
Moreover the information that is, somehow, passed from one generation to another is contained inside each individual and ‘entrusted’ individually and ‘personally’ – not by an outside agent, as it maybe the case for the chemical systems we use in our labs or industries.

According to these ‘criteria’ viruses would be alive while computer programs ‘not yet’. Not until they’ll learn to replicate themselves in a manner flexible enough to be called ‘evolutive’.