Evolution

The concept of biological evolution is most commonly associated with Charles Darwin's [The Origin of Species by Means of Natural Selection]

, subtitled [or the Preservation of Favoured Races in the Struggle for Life]

. Thus evolution is contrasted with the fixity of specially created species and presupposes development. Darwin indicated a mechanism for what had already been postulated, that the variety of life is the outcome of a gradual process of descent from one or more very simple forms.

This apparent upset to established religious ideas, based on the first chapter of Genesis, lead to the presumption of a divine "orderer", development thus following as a consequence of fundamental regularities or laws in the universe. There is no rational interpretation of the laws of natural selection resulting in the survival of the fittest as therefore implying the survival of the best, unless the best is simply defined as the fittest to survive; "Scientific statements of facts and relations ... cannot produce ethical directives" (Albert Einstein). Nevertheless, the development of more complex and, arguably, better forms does arise from the simple. Long before "The Origin of Species" Aristotle argued that life arose from metamorphosis of inorganic matter; plants arose first, with powers of nourishment and reproduction; then zoophytes, then animals with powers of sensibility and, to some extent, thought; then man, with the ability for abstract thought. Viewed this way, nature is an evolution from the lower to the higher, a struggle towards perfection. Aristotle himself was unable to resolve the question as to whether the perfecting principle, or [efficient cause]

, was an original impulse which thereafter remained outside of nature, or whether it is continuously at work.

In scientific terms, it is clear that mankind has now theoretically the power to decide which species shall survive and, within our own species, to determine genetically how mankind itself will survive. Thus there is an element of choice in the matter of how development will continue; but this choice still has to be based on ethical arguments, the facts of themselves do not determine how the choice should be made.