Fido the Yak

How do we define life in such a way as to include mules and other non-reproducing organic entities? This debate has found its way into the field of astrobiology. Vera Kolb takes the position (pdf) that we should distinguish between life (zoë) and the living being (bios). Her position is taken in response to a paper (pdf) by Carol Cleland and Christopher Chyba, who argue that if life is a natural kind, there should be a single definition to describe it. I am partial to Cleland and Chyba's view, but Kolb raises an interesting point regarding our old friend ouisa. Kolb says:

In his 'Categories' Aristotle developed a theory of classification of existing things (Aristotle 1963). He introduced the notion of a substance, which is a fundamental ingredient of reality. He proposed ten categories : substance, quantity, quality, relation, place, time, position, state, action, and affection. Substances may be primary or secondary. His examples of primary substances are an individual man or a horse. He terms the species such as 'men' and the genus such as 'animal' as secondary substances. It is fascinating that Aristotle placed an individual living organism higher in the classification than its species or genera. He stated that the individual substance does not lose its qualities as it becomes part of a species and genera. However, this is a one-way road, since the converse is not true. The species and genera are, in today's language, information poor as compared with the individual. Aristotle concluded that manhood, which would be a generic description of the properties of all men in the species, is not contained in the primary substance, which is an individual man. General is not present in specific ; abstract is not present in the real. This approach places the individual above its species and points to the uniqueness of the individual. More on Aristotle's views on substances are found in his 'Metaphysics', Book Z, and also Book H (Aristotle 1979). While Aristotle's concept of substances changed somewhat, for our purposes his original view, from 'Categories', is most applicable. Aristotle's view of the primary substance acknowledges that an individual is unique. In 'Categories' he also stated that the individual substances cannot be ranked. We believe that this principle is still valid. Each individual living organism has its unique place in the Universe. This view assigns the utmost importance to an individual living organism, in contrast with some contemporary reductionist views such that an individual organism is just a carrier of the selfish genes (Dawkins 1989).

(pp. 4-5)

I'm sure some thinkers will see a problem with linking uniqueness to ousia. Should astrobiology acknowledge the uniqueness of every living organism? On what grounds?

Labels: Aristotle, Chyba, Cleland, Kolb, life, mules, ouisa, uniqueness

posted by Fido the Yak at 2:40 PM.