In the early 1600s, a certain Italian astronomer came into conflict with the Catholic Church over his support of the Copernican view that the Earth revolves around the sun. Galileo, himself a Catholic, was tried for heresy in 1633 by the Roman Inquisition
, which forced him to recant his views and live out his days under house arrest. It wasn't until 2000 that former pope John Paul II issued a formal apology for the church's treatment of Galileo.
The church's views on evolution have themselves evolved over the years. For the first hundred years or so after Charles Darwin
first put forth his theory, the church took no formal stance on evolution, though some church figures rejected it. As late as the 1950s, the church maintained a neutral position on the subject, but by the end of the 20th century the Catholic Church showed general acceptance of 'theistic evolution,' which states that God created a universe where cosmic and biological evolution occurred.
"The theory has been progressively accepted by researchers, following a series of discoveries in various fields of knowledge," former pope John Paul II said in a speech to the Pontifical Academy of Sciences at the Vatican in October 1996. [The Top 10 Intelligent Designs (or Creation Myths)
When it comes to reproductive issues like contraception and abortion, the Vatican has taken a consistently conservative stance. In 1968, Pope Paul VI formally rejected the use of contraception
, including sterilization, in his encyclical "Humanae Vitae" (On Human Life). "An act of mutual love which impairs the capacity to transmit life which God the Creator, through specific laws, has built into it, frustrates His design," the pope wrote.
To combat the scourge of HIV/AIDS, the church advocates monogamy and abstinence before marriage over the use of condoms. The church has been a world leader in providing care for victims of HIV/AIDS, but Pope Benedict XVI drew fire from health experts in 2009 when, while on a trip to Africa, he stated that condoms would worsen the AIDS epidemic
"You can't resolve it with the distribution of condoms," the pope said of the AIDS crisis. "On the contrary, it increases the problem."
In recent years, the church has taken issue with research using human stem cells, which have the ability to develop into different tissue types, making them promising for disease therapies. The church has mainly confined its opposition to the use of embryonic stem cells because of the Catholic view that life begins at conception.
''Scientific research must be encouraged and promoted, so long as it does not harm other human beings, whose dignity is inviolable from the very first stages of existence,'' Pope Benedict XVI said in June 2007, the New York Times
"The main question should be what benefit can come out of stem cell research," Utkan Demirci, a stem cell researcher at Harvard University Medical School and Brigham and Women's Hospital, told LiveScience. "The potential benefit of stem cell research is huge."
The Pontifical Academy of Sciences held a workshop on stem cell research in 2012. The event focused on the potential of induced pluripotent stem cells, which have the ability to develop into different cell types, but don't have to come from embryos.
The workshop is a good example of how the Vatican is willing to listen to scientists, said Arber (president of the academy).