Here’s a look at the Vatican’s walking-on-eggshells attitude toward Darwin’s theory of evolution, and their apparent dismissal of the “intelligent design” form of creationism: Reconciling Science, Religion.

“The ongoing and vigorous engagement of the Catholic Church with evolutionary theory reflects, in my opinion, a fluid and dynamic pathway that combines a profound sense of continuity with its historical past and a living and open, experiential response to … the discoveries of science,” said Robert J. Russell, founder of the Center for Theology and Natural Sciences in Berkeley, Calif.

Russell, a physicist and minister in the United Church of Christ, will be one of the speakers next month at a Vatican-sponsored conference marking the 150th anniversary of Darwin’s book, “The Origin of Species.”

In recent years, however, with the growing prominence of “creationism” and “intelligent design” as alternative explanations for the existence of humanity and the universe, Catholics have increasingly voiced doubts about Darwin’s acceptability. Cardinal Christoph Schoenborn, a friend and former student of Pope Benedict’s, provoked controversy with a 2005 article arguing that “neo-Darwinian dogma” is not “compatible with Christian faith” and insisting that the “human intellect can readily discern purpose and design in the natural world.”

That the cardinal published his article with the encouragement and assistance of proponents of intelligent design gave the impression that a high church official was endorsing ideas that most scholars reject as unscientific. Schoenborn has since attempted to clarify his position, insisting that he rejects not the theory of evolution, but arguments that use Darwin’s ideas to disprove the existence of a creator-God.

The Rev. Marc Leclerc made the same distinction recently in L’Osservatore Romano, the Vatican’s newspaper. “Evolution and creation do not present the least opposition between them,” he wrote, “on the contrary, they reveal themselves as entirely complementary.”

Leclerc, lead organizer of the upcoming Darwin conference, said last year that no proponents of creationism or intelligent design had been invited to the event.

Yet the Vatican’s embrace of Darwin remains a qualified one. The conference is “not, even minimally, a ‘celebration’ in honor of the English scientist,” Leclerc said. “It is simply a matter of taking stock of the event that has forever marked the history of science and has influenced how we understand our own humanity.”