To understand the implications of the Darwinian revolution, it is necessary to understand the world view it replaced. This chapter provides a brief introduction to Darwin's theory of evolution by natural selection by presenting it as a successor to the scientific revolution of the sixteenth and seventeenth centuries, and as having the potential to complete the overthrow of the traditional ways of thinking that the earlier revolution had begun.
In particular, it distinguishes between teleological and non-teleological explanation, and shows Darwin's theory as relying on non-teleological explanation in contexts where teleological explanation had previously seemed essential.
When The Origin of Species was published in 1859, it not only offered a radically different account of animal origins from anything there had been before, but also carried the unmistakable implication that most traditional beliefs about our own nature and our destiny would need equally radical reconsideration. The zoologist G. G. Simpson, writing in 1966, said that all attempts to answer questions about the nature of human beings and the meaning of life before 1859 had been worthless, and that we should be better off if we ignored them completely (Simpson (1966)).
This book is about the implications of the Darwinian revolution for our understanding of ourselves and our situation, and in particular about the extent to which it demands changes in traditional ideas about the kind of thing we are. But to understand the extent of any such changes it is necessary to know what they are changes from; and since many of the most deeply rooted ideas of human nature are of ancient origin, it will be useful to go back not just to the world into which The Origin of Species exploded, but further still, to the time before the first scientific revolution of the sixteenth and seventeenth centuries, and consider how the world seemed to Western people then.
This will also be useful for another reason. The scientific revolution that began in 1543 with the publication of Copernicus's idea that the earth was a planet in orbit around the sun, and reached its watershed with the publication of Newton's Principia in 1687, is now far enough in the past to allow us to see clearly what kind of change it involved and how much difference it made to people's understanding of themselves and their position. Since we are still in the thick of the Darwinian revolution the situation is much less clear, and the earlier revolution will provide some useful illustrations and analogies.
So, bearing in mind that this can be nothing more than the sketchiest of sketches, start by considering the situation before Copernicus (1473-1543), Galileo (1564-1642) and Newton (1643-1727).