A few naturalists, endowed with much flexibility of mind, and who have already begun to doubt on the immutability of species, may be influenced by this volume; but I look with confidence to the future, to young and rising naturalists, who will be able to view both sides of the question with impartiality. Whoever is led to believe that species are mutable will do good service by conscientiously expressing his conviction; for only thus can the load of prejudice by which this subject is overwhelmed be removed.
A very nice call to action here, he's simultaneously defending himself by anticipating the inevitable backlash while addressing those who may have taken his ideas to heart. Perhaps this is an example of a major social evolution, something that might become archeologically invisible far into the future but observable as of right now. He really believed in his ideas! It really exemplifies how revolutionary this book was, it really was the first of its kind.