Chris Graney
“For most of its history, the Catholic Church rejected scientific findings that contradicted its doctrine.” I work for the Vatican astronomical observatory, and last year when a correspondent for a major news organization did an article about the observatory, the editors felt the need to preface the story with that statement. Some people are simply fixated on the idea that the Church rejects science.
St. Thomas Aquinas could guide them, using astronomy and Genesis as examples.
In Genesis, God says, “let there be lights in the firmament of the sky,” and we hear that “God created the two great lights [the sun and moon]…and he created the stars.” If these bodies were all lights in a sphere, they would all be the same distance from Earth. The sun and moon, which appear to be the largest celestial lights, would also be the largest in physical mass.
But by the second century, astronomers such as the Greco-Egyptian astronomer Ptolemy had determined that the sun is more distant than the moon and the stars even more distant. Ptolemy said that the stars were so distant that the Earth was a tiny speck in comparison. For the stars to appear as they did in the sky, but be so far away, meant that they had to be much larger in mass than the moon.
Ptolemy’s arguments were convincing to Christian writers. They did not reject science. For example, St. Severinus Boethius refers to the Earth as a point, and mentions Ptolemy by name, in the Consolation of Philosophy which he wrote around 525. St. Augustine, the fifth-century African bishop who had even more influence on Christendom than Boethius, discussed the stars being too large in his book On the Literal Interpretation of Genesis.
St. Thomas Aquinas, the 13th-century Italian theologian who has been as influential as St. Augustine, also considered the question of star sizes. In his Summa Theologica, Question 70, discussing the fourth day of creation, he notes that “as the astronomers say, there are many stars greater than the moon. Therefore the sun and moon alone are not correctly described as the two lights of gave me.” To this he replies, “the two lights are called great, not so much from their dimensions, as from their influence and power. For though the stars have a greater mass than the moon. . . . as far as the senses are concerned, the size of his visible is greater.”
Aquinas did not reject science. Using the principle that one true thing cannot contradict another, he interpreted Genesis as describing the heavens as they appear to us, not as describing the absolute size of the moon.
But this kind of interpretation was never to be used lightly. Galileo argued that the Earth revolved around the sun; thus the biblical verses that describe the sun as moving describe things as they appear to us. Church leaders such as Cardinals St. Robert Bellarmine and Carlo Conti told Galileo that yes, that interpretation could be made, but, as Conti put it, “this mode of interpretation should not be accepted without great necessity.” The question was, did the scientific evidence demand this? Was there a necessity? Church officials who questioned Darwin’s theory of evolution in the late 19th century used the same logic.
Science changes. The development of new instruments such as the Webb telescope ensures this. By contrast, the principle that one truth cannot contradict another is eternal. Without some caution, we would constantly reinterpret Scripture in light of this or that scientific idea that did not stand the test of time. St. Thomas Aquinas might say that care and respect for Scripture is hardly a rejection of science.
Chris Graney, a parish priest of the Church of St. Louis Bertrand, is on the staff of the Vatican Observatory, www.vaticanobservatory.org.