 The explanatory methodology of Darwin’s theory also provided him with a means of defeating certain major objections, such as those drawn from the existence of organs of great complication and function. To deal with the question of the vertebrate eye in chapter six, for example, Darwin offered a few speculations on how such a structure could have developed by the gradual selection upon the rudimentary eyes of invertebrates. But the primary solution offered was the ability of his theory to draw together in its total argument numerous lines of inquiry that would not otherwise receive a coherent explanation. In such a case one would 