Much as the Protestants took medieval Catholic ideas about literacy and education in new directions, they also participated heavily in the development of science based on earlier medieval Catholic precedents. As early as the 12^th century, a worldview had developed that historians have labeled “Platonic humanism.” This worldview argued that the world came from God, and therefore studies of the world could lead us back to God. This began a transformation of Western culture’s way of seeing the world, including growing realism in art and the development of medieval science.

Medieval Science and Empirical Observation: Grosseteste and Bacon

Oxford University was a particularly important center for scientific advancement. Robert Grosseteste (c.1170-1253), who taught in the Franciscan convent at Oxford, was the first medieval thinker to understand Aristotle’s methodology, which amounted to an early form of the scientific method. Grosseteste was also one of the first to rediscover that mathematics was the foundation for “natural philosophy,” as the natural sciences were then called.

He was soon followed by Roger Bacon (c.1214-1294), who agreed with Grosseteste about the centrality of mathematics to natural philosophy and in arguing for first-person observation as the foundation for knowledge. Bacon applied these methods to a wide variety of fields and predicted technological breakthroughs reminiscent of Leonardo da Vinci and Jules Verne.

But Bacon wasn’t only interested in natural philosophy. He recognized that his methodology focused on direct observation could apply to other areas of study. Academic life in the middle ages was dominated by a method of study known today as scholasticism. Scholastics based their educational system on ancient authors, who were always read along with glosses (similar to paraphrases), commentaries, and other academic works. This meant that interpretations of these texts were always controlled by other people’s thoughts about the texts; the texts were not allowed to speak for themselves.

Bacon thought this methodology fundamentally flawed. Specifically, he was upset with the theologians at the University of Paris who relied primarily on Peter Lombard’s “Sentences” to teach theology, and turned to Scripture only after their study of the “Sentences.” To make matters worse, they refused to learn the biblical languages and instead relied on what Bacon saw as obviously defective copies of the Latin translation of the Bible.

Instead of this, Bacon advocated studying the Bible first, and only then moving to the “Sentences.” Further, he believed that the Bible should be studied in the original languages, not just in Latin, since that was the proper way to make firsthand observations of the text. This order—Bible, then “Sentences”—became the standard at Oxford (though not at Paris) even though his emphasis on the original languages wouldn’t get off the ground until the Reformation.

Renaissance Humanism

Empirical science thus has its roots in medieval Franciscan theologians, though it only reached its Golden Age during the Scientific Revolution of the 16^th and 17^th centuries. There were several reasons why this period was particularly ripe for empiricism. First was the rise of Renaissance humanism in the 14^th century. This led to a curriculum of studies that was based on direct study of ancient texts free from glosses and commentaries, and ideally in the original languages, much as Roger Bacon had advocated. By the late 16^th century—after the rise of Protestantism—this approach to texts helped to create a mindset that encouraged direct observation of the natural world as well, rather than relying on what others had said about it. This progression from firsthand study of texts to firsthand study of the natural world mirrored the progression in Bacon’s thought, and not surprisingly led to similar conclusions about scientific methodologies.

On the other hand, the connection between Renaissance humanism and the development of empirical science should not be pushed too far. Renaissance thinkers were far more interested in other areas of philosophy and literature than they were in science. The influence of humanism on science would not be seen until the rise of Protestantism.

Further, Renaissance humanists were obsessed with the ancient world and still believed that ancient authors were the best source for truth about anything, even science. This obsession with ancient writings meant that various magical traditions from the pagan world were believed to be true explanations of how the world worked. This made the Renaissance the Golden Age of magic theory more than the Golden Age of science: Many Catholic and Protestant thinkers believed that the universe was controlled by “occult” (hidden) forces that could be manipulated by those who understood them. Thus, while there are important connections between the Renaissance and the Scientific Revolution, it can be misleading to tie them together too closely.

Protestantism, Empiricism, and Science

Renaissance humanism had a direct effect on the Protestant Reformation; in fact, the doctrinal developments at the heart of the Reformation came about because of the adoption of humanist methods of study. Like the Renaissance humanists, Protestants opposed medieval scholasticism and emphasized direct study of Scripture; from there, Protestants and Catholic humanists alike took the small but important step of rejecting scholastic explanations of the natural world in favor of direct observations.

Protestantism thus contributed to the Scientific Revolution, but it did not cause it. Catholics and Protestants alike participated in the development of modern science: Copernicus and Galileo were Catholics, while Tycho Brahe, Kepler, and Newton were Protestants; Vesalius was Catholic, Harvey was Protestant; Descartes and Pascal were Catholics; Francis Bacon and Robert Boyle were Protestant. All were building on the foundation of medieval science, and all consciously affirmed certain key ideas derived from the Bible seen through a lens that originated with Platonic Humanism: God is a rational being; as a rational being, the universe that He created must be rational; human beings are made in the image of God, and therefore are also rational; thus it must be possible for human beings to “think God’s thoughts after him,” as Johannes Kepler put it, and to discover the laws of nature that God built into the universe; doing so is a theological enterprise, since it reveals the mind of God. Every major thinker in the Scientific Revolution held to these views, and most articulated them explicitly.

Johannes Kepler (1571-1630)

Kepler is a good example. A devout Lutheran, he planned to become a pastor. He excelled at mathematics, however, and had an interest in astronomy from childhood. While studying at the university, he learned both Ptolemaic and Copernican astronomy. He was convinced by Copernicus and defended his ideas on both scientific and theological grounds.

Kepler began to work in astronomy and became the assistant to Tycho Brahe, the greatest observational astronomer to that point in history. Kepler and Tycho were working together on a set of tables of planetary motion when Tycho died unexpectedly in 1601. Kepler was appointed Tycho’s successor as imperial mathematician by Holy Roman Emperor Rudolf II. Kepler was able to use Tycho’s observations to demonstrate mathematically that the planets orbited the sun and discovered the laws of planetary motion that Newton would later confirm.

Kepler’s work was motivated by a complex set of ideas. First and foremost, he was a Christian natural philosopher: He believed that a rational God created a rational universe, and we as beings made in God’s image are also rational and can therefore work out the laws governing the universe. In many ways, this was the governing principle behind all of his work.

This commitment to understanding the mind of God through the creation led him to be an absolutely rigid empiricist. He believed that God gave him Tycho’s data, and thus it was his responsibility before God to use it to the full. Particularly remarkable is how far he was willing to go with this. For example, every astronomer in Kepler’s day believed that the heavenly bodies moved in perfect circles. But Kepler’s analysis of Tycho’s observations showed that the planets move in ellipses. The difference between circles and the planets’ ellipses is minuscule: The earth’s orbit is only 1 part in 6,000 away from being circular. Yet for that small amount, Kepler was willing to jettison the idea that heavenly bodies move in perfect circles. Most other natural philosophers would have chalked that up to observational error and kept circles, but Kepler knew the margin of error of Tycho’s observations, and he believed God expected him to honor the quality of the data, not to make it conform to his preconceptions about how it “should” be.

Kepler was also the last great Pythagorean natural philosopher. Like the ancient Greek philosopher and mathematician Pythagoras, Kepler believed that God was a geometer, and that geometry held the key to understanding the universe. And of course, he was a committed Copernican. These motivations, along with Kepler’s mathematical genius, all interlocked to lead Kepler to discover the laws of planetary motion.

The development of modern science was an outworking of ideas about God, the Creation, and human nature derived from the Bible and articulated by medieval theologians, though frequently obscured by their educational methodologies. Renaissance humanism began to change that, and with the rise of Protestantism a truly empirical approach to understanding the natural world developed, paving the way for modern science. The foundations for science were thus found in a profoundly biblical worldview shared in large measure by Catholics and Protestants alike.