2 - Approaches to the definitions of life

Summary

Introduction

In this chapter two related questions will be considered. Firstly, the definition(s) of life; secondly, the ideas on how to implement such views on life in the laboratory. The idea of defining life is generally met with scepticism or benevolent nods by a large number of scientists. The arguments behind this negative attitude are various: such an enterprise is deemed neither useful nor easy, since everybody knows what life is, but to describe it in words is impossible. A slightly more sophisticated argument is based on the assertion that the transition from non-life to life is a continuous process, and therefore the discrimination between the living and the non-living is impracticable.

This negative attitude has several components, which have been partly analyzed (Luisi, 1998). One main problem is that the term “life” is too vague and general, and loaded with a number of historical, traditional, religious values. In particular, in the Christian tradition, the term life is generally linked to the notion of soul – and in Buddhism is linked to the notion of consciousness.

Of course, this is too much of a big picture and to define life at this level may indeed appear impossible. However, one can scientifically tackle this question by looking at life in its simplest expression, namely microbes and other unicellular organisms. This is a first, important clarification, which also eliminates (at least for most scientists) the notions of soul or consciousness from the picture.