The first set of objections is associated with the name of the late Stephen Jay Gould, and this approach goes by the name of ‘punctuated equilibrium’. It should be stressed that – as Richard Dawkins himself has written, “the theory of punctuated equilibrium lies firmly within the neo-Darwinian synthesis.” The difference between Dawkins and Gould is rather technical, but illuminating nonetheless. ‘Orthodox’ neo-Darwinism – by which I mean that understanding described above, associated with Dawkins – asserts that the pressure which natural selection exerts is a gradual process; that species change in small amounts over vast stretches of time; and that this selection pressure operates through the genetic inheritance passed on from parent to child. Gould disputes this emphasis upon the gene – for him, not only is there a significant amount of luck involved in inheritance, but the pressures of natural selection bear down upon the individuals, not just their genes. Put differently Gould disputes the ‘genetic determinacy’ associated with the orthodox neo-Darwinian account. For Gould, much of Dawkins’ understanding is accepted, but Gould’s outlook allows more room for random chance (e.g. asteroid impacts), and also a slightly different notion of what science can and cannot achieve. For Gould science is not immune to cultural influences, and there is much in human history that cannot be sufficiently explained by reference to natural selection, or indeed, by any scientific outlook. Gould’s writings take much from the realms of literature, history and religion – and are much richer as a result.

The second set of objections is one which is presently gaining ground in the United States of America, and comes in two varieties – ‘creation science’ and ‘intelligent design’. Put simply, these understandings of the universe derive from a more or less literal rendering of chapter one of the Book of Genesis in the Bible, so that the source of the diversity of life as we experience it is explained as a choice by God. Depending on the particular type of creation science advocated, the earth is seen to be only a few thousand years old, and the variation of life experienced is explained by describing the inexhaustible creativity of God. Intelligent design is a slightly different account, although it shares some assumptions; it accepts that the earth has existed for billions of years, but sees the change in different species – and most particularly the development of human intelligence – as something which results from a direct intervention in the universe by God. These approaches argue that the intelligent cause can be identified with the Judaeo-Christian deity, the ‘God of the Bible’. Their understanding grants authority to a religious text and a tradition of interpretation of that text, and they point out the various problems with the theory of evolution, which, on their accounting, leave room for that traditional religious commitment. The creation scientists go one step beyond the intelligent design theorists, in that their tradition of interpreting the Bible requires a strictly literal rendering of the account of creation given in the Book of Genesis. They reject the notions of natural selection, evolution, and indeed the generally accepted timescale provided by modern science, considering that the universe is only some few thousand years old.

How are we to determine the truth between these different accounts? The conventional view – and I imagine the one that Professor Dawkins would advocate – would be to examine each point of view and ask: does this point of view make sense, is it logically consistent? And then ask: what is the evidence for each point of view? Which point of view is best supported?

So let us look at logic and evidence.