Thoughts about the Definition of Life - CM Trying to define life proves to be an exceedingly difficult task. Many criteria such as self-reproduction, adaptability, etc. are usually invoked to determine the boundary 'features' of life. In a certain sense this defines 'life' by the method of exclusion and - quite reasonably - considers the question under a predominantly bio-chemical perspective. Of course, other views are possible. What about 'the soul', for example? 'The soul' seems to be inseparable from the notion of life, irrespective of what finally constitutes this enigmatic 'feature'. Also the question whether structures much larger than what normally think of in this connection may be thought of as a manifestation of 'life' is an intriguing one. Although I do not subscribe to it, the Gaia theory, for example, opens a perspective of thinking which we should not overlook. Claus Madsen, European Affairs Officer European Southern Observatory (ESO)