On November 24, 1859, the English naturalist Charles Robert Darwin published On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life . In that book (Darwin 1859), he argued that all organisms, living and dead, were produced by a long, slow, natural process, from a very few original organisms. He called the process “natural selection,” later giving it the alternative name of “the survival of the fittest.” This first chapter is devoted to presenting (without critical comment) the argument of the Origin, very much with an eye to the place and role of natural selection. As a preliminary, it should be noted that the Origin, for all it is one of the landmark works in the history of science, was written in a remarkably “user-friendly” manner. It is not technical, the arguments are straightforward, the illustrative examples are relevant and easy to grasp, the mathematics is at a minimum, meaning non-existent. Do not be deceived. The Origin is also a very carefully structured piece of work (Ruse 1979a). Darwin knew exactly what he was doing when he set pen to paper.