In the preface of the book, Charles Darwin explains the progression of the theory of descent with modification and the conception of natural selection up until his time period of the 1850’s. He begins by stating the major opinion of the people was that species were all separate beings of which were created individually and that this concept had been ingrained into common thought by many authors. However, according to Darwin, opinion has started to shift towards a new idea. Darwin states that few people have begun to believe that species underwent change and that existing species were descendents of pre-existing forms. Charles Darwin later writes about the various past philosophers that believed in and understood the concept of natural selection. Philosophers mentioned include Aristotle and Dr. W.C.Wells. To end this section, the author shows various reasons as to why and how changes in organisms were triggered in the form of the beliefs of many philosophers and scientists. The main causes were geographical distribution, germs causing analogous change, and destruction of intermediate graduated forms of a species. The main idea that was found in all of these theories was that species were created due to some form of stimulation that forced species to change in order to survive. …show more content…
Hooker. However, the author could’ve been more convincing if he added some reasons as to why people should trust the people he had selected. As for the ideas, I found the main one to be that species were generated as a result of a stimulus. This stimulus ranges from a geographical change (location difference) to the introduction of a competing species. This idea of change causing change is alluded to several times in the preface which is why I believe that it is the principle