the catholic church has never contradicted itself

As Con I will be arguing that the Catholic Church has contradicted itself at least once in 2,000 years' history. As requested, I will not count issues of limbo or "no salvation outside the Catholic Church". Pro states that "the only things that count are statements that are authoritative, things that could be considered 'infallible'." While I find this criteria rather subjective, it goes without saying that the Pope represents the Catholic Church and his word is final and infallible, as he is the closest living man on Earth to God's word. While the Pope teaches on faith and morals, a part of this has always been the upholding of Biblical and doctrinal integrity through refutation of scientific advancements. This will be my main line of argument. Has a Pope in the last 2,000 years said something later or earlier contradicted by another Pope in the same timespan? I say absolutely. As the topic is resolved the BOP lies with Pro. As long as I can prove a single instance of two Popes within 2,000 years contradicting each other the debate is clearly my win. Pope Pius XII addressed the issue of evolution in a 1950 encyclical, Humani Generis. Here he makes plain his fervent hope that evolution will prove to be a passing scientific fad while attacking those persons who "imprudently and indiscreetly hold that evolution " explains the origin of all things." He wrote: Fictitious tenets of evolution which repudiate all that is absolute, firm and immutable, have paved the way for the new erroneous philosophy which, rivaling idealism, immanentism and pragmatism, has assumed the name of existentialism, since it concerns itself only with existence of individual things and neglects all consideration of their immutable essences. LESS THAN 50 YEARS LATER, Pope John Paul held an address that caused a commotion within the Catholic community because his liberal acceptance of evolution as a valid theory, factually supported, was considered by many to be contrary to Biblical doctrine. This article was written by a Catholic Christian organization on the matter: http://biblelight.net... It states: Pope John Paul II, on the 23rd of October, 1996, while speaking to the Pontifical Academy of Sciences plenary session at the Vatican, declared the evolutionary theories of Charles Darwin to be fact, tacitly acknowledging that man evolved from the apes, and reducing the biblical account of Genesis to that of mere fable! I think they may have been exaggerating the extent of John Paul's claims, but it remains certain that at one point the Catholic Church taught that evolution was unfounded and fictitious, only to change tack 46 years later by saying it is a valid scientific theory not disproven by the Bible. We find the same pattern with concepts like heliocentric theory, birth control and aspects of education. The fact is, each Pope has their own opinion and interpretation of the Bible and God's word. To expect that all Popes in 2,000 years of history and upheaval and cultural change all agree on the same topics is ignorant of the great variety of human belief and the scientific progress developing in this time. I await my opponent's response.