are complementary, not contradictory: In a book released in 2008, his comments prior to becoming Pope were recorded as: On September 2–3, 2006 at Castel Gandolfo, Pope Benedict XVI conducted a seminar examining the theory of evolution and its impact on Catholicism's teaching of Creation. The seminar is the latest edition of the annual "Schülerkreis" or student circle, a meeting Benedict has held with his former Ph.D. students since the 1970s. The essays presented by his former students, including natural scientists and theologians, were published in 2007 under the title Creation and Evolution (in German, Schöpfung und Evolution). In Pope Benedict's own contribution he states that "the question is not to either make a decision for a creationism that fundamentally excludes science, or for an evolutionary theory that covers over its own gaps and does not want to see the questions that reach beyond the methodological possibilities of natural science", and that "I find it important to underline that the theory of evolution implies questions that must be assigned to philosophy and which themselves lead beyond the realms of science." In July 2007 at a meeting with clergy Pope Benedict XVI noted that the conflict between "creationism" and evolution (as a finding of science) is "absurd:" In commenting on statements by his predecessor, he writes "it is also true that the theory of evolution is not a complete, scientifically proven theory." Though commenting that experiments in a controlled environment were limited as "we cannot haul 10,000 generations into the laboratory", he does not endorse Young Earth Creationism or intelligent design. He defends theistic evolution, the reconciliation between science and religion already held by Catholics. In discussing evolution, he writes that "The process itself is rational despite the mistakes and confusion as it goes through a narrow corridor choosing a few positive mutations and using low probability.... This ... inevitably leads to a question that goes beyond science.... Where did this rationality come from?" to which he answers that it comes from the "creative reason" of God. The 150th anniversary of the publication of the Origin of Species saw two major conferences on evolution in Rome: a five-day plenary session of the Pontifical Academy of Sciences in October/November 2008 on Scientific Insights Into the Evolution of the Universe and of Life and another five-day conference on Biological Evolution: Facts and Theories, held in March 2009 at the Pontifical Gregorian University. These