The Blind Watchmaker is a 1986 book by Richard Dawkins in which he presents an explanation of, and argument for, the theory of evolution by means of natural selection. He also presents arguments to refute certain criticisms made on his previous book The Selfish Gene. (Both books are intended to popularise the gene-centric view of evolution.)
In his choice of the title for this book, Dawkins makes reference to the watchmaker analogy made famous by William Paley in his book Natural Theology. Paley, arguing more than fifty years before Charles Darwin published The Origin of Species, held that the complexity of living organisms was evidence of the existence of a divine creator by drawing a parallel with the way in which the existence of a watch compels belief in an intelligent watchmaker. Dawkins, in contrasting the differences between human design and its potential for planning with the workings of natural selection, therefore dubbed evolutionary processes as analogous to a blind watchmaker.
In developing his argument that natural selection can explain the complex adaptations of organisms, Dawkins' first concern is to illustrate the difference between the potential for the development of complexity of pure randomness as opposed to that of randomness coupled with cumulative selection. He demonstrates this by the example of the Weasel program. Dawkins then describes his experiences with a more sophisticated computer model of artificial selection implemented in a program also called The Blind Watchmaker, which was sold separately as a teaching aid.
In an appendix to a later edition of the book (1996), Dawkins explains how his experiences with computer models led him to a greater appreciation of the role of embryological constraints on natural selection. In particular, he recognised that certain patterns of embryological development could lead to the success of a related group of species in filling varied ecological niches, though he continued to maintain that this should not be confused with the ideas associated with group selection. He dubbed this insight the evolution of evolvability.
After arguing that evolution is capable of explaining the origin of complexity, near the end of the book Dawkins uses this to argue against the existence of God: "a deity capable of engineering all the organised complexity in the world, either instantaneously or by guiding evolution, . . . must already have been vastly complex in the first place . . ." He calls this "postulating organised complexity without offering an explanation."
In its preface, Dawkins states that he wrote the book "to persuade the reader, not just that the Darwinian world-view happens to be true, but that it is the only known theory that could, in principle, solve the mystery of our existence."