Pierre Teilhard de Chardin was not only the theologian who did the first wide effort to introduce inside the roman catholic theology the suggestions given by evolutionary biology, but also a scientist and one of the most world wide known palaeontologists of the twentieth century. After his first european experiences he worked for about twenty years in China where he developed vertebrate palaeontology and was one of the members of the team that worked at the remains of the so called Peking man.
The nine lettres reported in this volume were sent by Teilhard de Chardin to his teacher and mentor in the Institute of human palaeontology in Paris, Marcellin Boule. They were written from the 13rd of october of 1929 to the 2nd of august of 1930 and covered the time between the discoveries of the first and the second skull of the Sinanthropus. They report about his travels and his comments on the skulls. Of great interest is the fact that quite often what he wrote in the letters was reported in his printed papers without major changes: this is a new proof that he was an excellent field palaeontologist and that his first sight perceptions were then confirmed during his labatory investigations.
The letters presented also his work on the Sinanthropus: first of all the necessity to get rigorous stratigraphical correlations in order to date accurately the remains. For these reasons he was compelled to work with Rodents and from this point came out his main work on the parallelism in the evolution of the Chinese mole-rats, a proof of the peculiarity of the continental evolution and of the advantages of a global approach considering the Biosphere as a whole evolving object. Moreover he suggested some aspects of human evolution and migration which were useful in order to explain the presence and evolution of the Sinanthropus.
The main interest of these letters is that they pose again the problem of the scientific contribution of Pierre Teilhard de Chardin to the theories of evolution: he was one of the forerunners of the global approach to evolution and to the present days discussion on complexity. These letters are a new proof that his scientific correspondence still widely unpublished, will be a source of information to these new approaches of biology. The biology of the next century will be the biology whose very basis were posed by Teilhard de Chardin.