The Religious Roots of the Scientific Method

The visionary genius of Nicholas of Cusa.

The mindset of the Modern world began with the polymath Nicholas of Cusa. Presaging later ideas in philosophy, theory of mind, mathematics, cosmology, astronomy, and experimental science, Nicholas of Cusa, also known as Cusanus, was the first intellectual heavyweight to break the grip of Aristotle and other ancient thinkers over human thought. 

Living three generations before Copernicus and writing 200 years before Galileo, Cusanus established a new method for scientific investigation and became one of the foundational thinkers of Early Modern Science. Highlighting the centrality of the relativity of perspective and the role of the observer in measurement, Cusa’s insights into the nature of reality anticipated Einstein’s Relativity Theory and 20th-century discoveries in quantum physics. Having more depth of insight into the physical mysteries of the Universe than anyone who had gone before him (and even most who came after), Cusa’s great source of scientific inspiration was his deep faith in the Creator God.

Experimentation, Measurement, and the Invention of Science

Photo by National Cancer Institute on Unsplash

Inspired by the example of Socrates, scholar, scientist, and theologian Nicholas of Cusa believed that the truly learned man is one who is aware of his own ignorance. On a Mediterranean voyage from Constantinople to Venice in the early 1400s, Cusanus received a mystical vision from God that would set modern science in motion for centuries to come. Inspired by an experience of what he called the “supreme gift of the Father of Lights,” Cusa developed this vision into a book that would soon become the most popular work of the age and a foundational text in the history of Modern Science. 

In his masterly treatise, On Learned Ignorance, Cusa presented a groundbreaking conception of God, humanity, and nature and proposed a method of “learned ignorance,” through which the human mind could rise above the limits of the senses and come to know both physical and spiritual reality at deeper levels of truth. 

Affirming that knowledge can be gained, “Not by the books [of philosophers], but by God’s books…which he wrote with his own finger”—namely the works of nature that God created—Cusa suggested a method of discovering truths about nature that is based on the idea of controlled experiment and accepting what we cannot know. He begins with the skeptical insight that attaining perfect or complete knowledge on this Earth is impossible. Thus, the only way forward is to approach truth by short, incomplete steps that are true as far as they go—but can never lead to absolute truth. 

Maintaining that perceptual knowledge is always perspectival and recognizing that the “self-restriction” of knowledge is an essential component of a genuinely “scientific” (or knowledge-producing) method, Cusa contended that genuine advances in knowledge can only be made when we become aware of the limits of human knowing. 

He contrasted his new method of “learned ignorance” with the kind of knowing used in scholastic disputation and also the kind of knowing used in the speculative metaphysics of Aristotle, Averroes, and other Classical philosophers. Cusa was skeptical of logic and reason as the sole tools of intellectual progress, and his new method embraced a more prominent role for numbers, quantities, and empirical observation as arbiters of truth.

Crafting a treatise entitled, On Measuring, Cusa outlined a method of studying nature (or natural philosophy) that would eventually give rise to modern science. Laying a solid theological foundation for the edifice of science, Cusa reminded his readers that “In creating the world, God used arithmetic, geometry, and likewise astronomy...For through arithmetic, God united things. Through geometry, He shaped them, in order that they would attain firmness, stability, and mobility in accordance with these conditions.” 

Consequently, to better understand the mind of God within his creation and the deeper logic of the natural world which God created, one must prioritize experimentation. To comprehend the laws which God instilled in nature, one must effectively combine natural philosophy with mathematics while employing careful observation and exacting standards of measurement. Only by carefully weighing, timing, and measuring the material from experiments could sufficient data be generated to build a mathematical description of nature and more fully understand the laws of nature behind the mathematics.

Inventing Spectacles and Visions Beyond Space and Time

Employing his newly formulated scientific method, Cusanus studied the causes of myopia and, in 1451, invented concave lens eyeglasses to correct visual deficiencies for the nearsighted. His research in this area paved the way for the development of modern optometry and the manufacture of various types of spectacles and scientific instruments which employ lenses (such as telescopes and microscopes).

Cusa also made significant discoveries in astronomy. At the time when Cusa wrote his work, On Learned Ignorance, China still believed that the Earth was flat, and Europe still embraced Aristotle’s and Ptolemy’s understanding of the Universe as a spherical cosmic nesting doll with Earth at the center. In this Classical model of the cosmos, the sun and planets were fixed onto crystalline spheres in concentric circles around the sphere of Earth, and a corona of fixed stars orbited the circumference of the planetary spheres once per day. 

Beyond the outer sphere of fixed stars—a realm thought to be made of an incorruptible “fifth essence”—were the heavens and the Prime Mover who set the whole series of spheres in motion. The halo of the pure fixed stars was thus thought to be nearest to God, while the impure and corruptible Earth in the center was farthest away. (Contrary to Sigmund Freud’s contention, in the Medieval conception of the cosmos, the center of the Universe was not a special place to be.)

While most people today believe that this Aristotelian/Ptolemaic cosmological model was overthrown by the heliocentric Universe of Copernicus, in reality, Copernicus’s heliocentric model did not drastically depart from the Classical geocentric model because it retained a motionless center and periphery. Copernicus merely put the sun where Aristotle’s Earth had been while leaving the fixed stars and the rest of the model in place. 

It was not Copernicus—or even Galileo—who genuinely abandoned Aristotelian cosmology, but rather Nicholas of Cusa, who declared two hundred years before Galileo that all motion is relative to one’s inertial frame of reference and that the Universe has no center at all. “The Earth cannot be in the centre,” explains Cusa, “and just as the Earth is not at the centre of the universe, so the sphere of the fixed stars is not its outer border.” Although “the Earth moves through a vast expanse of space,” says Cusa, “we perceive ourselves to be at rest in the middle of the world because we lack an unmoved point of reference.” In other words, the Earth is moving, but we do not notice it because we are riding along with it.

Seeing Beyond Perfectly Spherical Orbits

Bounding over Copernicus, Galileo, Newton, and every other scientist before Einstein, Cusa applies the same principle of relative motion and perspective to every other cosmic body: “Everything moves in imperfect circles around its neighbors.” Precisely because nothing is at rest, says Cusa, “it always appears to every observer, whether on the earth, the sun, or another star, that one is...at an immovable center of things and that all else is being moved.” 

Because everything is at the center of the Universe—from its own perspective—nothing is at the center of the Universe in an absolute sense. Even the stars that were thought to be at the outer edge of the universe “occupy the center of creation from their own vantage point” so that their inhabitants would think that we orbit them.

Beyond this, contended Cusa, the orbits of the planets are not perfectly circular, as Aristotle and others held. “Even if it might seem otherwise to us,” says Cusa, “neither the sun nor the Earth nor any sphere can describe a perfect circle by its motion...Nor is a sphere’s or a star’s motion at one moment even precisely equal to their motion at another.” 

With his proposal that planetary courses are not quite circular, Cusa anticipates—by two centuries—Johannes Kepler’s discovery of elliptical orbits. Yet, the inspiration for this astronomical insight was a deeply theological conviction: “Circular orbits would entail precise equidistance between a central body and its satellites, and precise equidistance to different points cannot be found outside God, for God alone is infinite equality.” 

Envisioning a Finite, Yet Unbounded, Universe 

Cusa held that the Universe, in order to reflect God’s majesty in creation, must be limitless and unbounded but not infinite. The Universe, reasons Cusa, cannot be called finite “since it lacks boundaries within which it is enclosed, but neither can it be called infinite, because, unlike God, it is not ‘from itself.’” Since the source of its being lies beyond itself, says Cusa, the cosmos cannot, strictly speaking, be called infinite. And yet insofar as it “embraces all things that are not God,” it is not finite either. 

To better understand this concept, counsels Cusa, “You must make use of your imagination as much as possible and enfold the center with the poles.” The result will be something like a sphere whose center coincides with its periphery. If you can picture such an unpicturable thing, Cusa explains, will you begin to “understand something about the motion of the universe.” Moreover, he says, you will begin to understand the likeness between the Universe and its Creator. For insofar as God is both omnipresent and boundless, God himself can be thought of as “an infinite sphere, whose center is everywhere, whose circumference is nowhere.”

The Invention of Theoretical Physics and the Mathematical Mysteries of Infinity

As Cusa pioneered the use of symbolic logic and mathematical reasoning in science, he explained that mathematical figures cannot exist in the physical world (where something like absolute equality is impossible). However, he says because they exist in the mind of God and in our minds, “they allow the mind to grasp certain objects.” Mathematical figures are constructed by our reason, and because physical realities created by God are similar to them, the mind can measure the empirical figures against the ideal figures in the mind. 

Any knowledge of God’s works that we can gain is thus “derived from the symbolism and the mirror of [our] mathematical knowledge.” Using this unprecedented symbolic logic of mathematics, Cusa developed and made constant use of the mathematical concept of the “infinite.” Although he still considered an actual infinity impossible, Cusa was the first to study the concept of infinity mathematically, within the framework of an imaginary or theoretical physics.

Intelligent Life on Other Planets

Just as, for Cusa, there was no privileged place for any location in the Universe, for him, there is likewise “no distinction between the astral and sublunar spheres.” The elements that one finds on Earth are essentially the same as the elements that are found throughout the entire Universe. Because God is one, the laws of creation are also one, and contra Aristotle, the motions found in the realm of the stars are not of a different order than those observed on Earth. Rather than the order of things existing as a static hierarchy under an extra-cosmic God, reality is, instead, envisioned as a dynamic holography in which God is fully and equally present to everything in creation. 

This means, says Cusa, the stars are, in fact, other suns, and this planet is not “the only one.” Rather, affirms Cusa, there are a vast number of “earths,” and each of them may be full of inhabitants who probably think that they are at the center of a nesting-doll cosmos. Cusa believed that extraterrestrial life forms could most certainly exist elsewhere in the Universe. As Cusa expounds:

Life, as it exists here on Earth in the form of men, animals, and plants, is to be found, let us suppose, in a higher form in the solar and stellar regions. Rather than think that so many stars and parts of the heavens are uninhabited and that this Earth of ours alone is peopled—and that with beings perhaps of an inferior type—we will suppose that in every region, there are inhabitants, differing in nature by rank and all owing their origin to God, who is the centre and circumference of all stellar regions.

Espousing a view of the cosmos totally antithetical to Aristotle, not only did Cusa populate the “Divine regions of the cosmos” with celestial bodies composed of terrestrial elements, but he also populated those bodies with rational material beings. 

The End of Aristotle and the Beginning of Modern Science

A Roman Catholic Cardinal and one of the most theologically orthodox thinkers of his age, Nicholas of Cusa was also the founding father of the scientific method and a pioneer of multiple lines of thought which would lead to successive revolutions in science. The history of science would, in time, confirm the validity of the Cusan approach to knowledge through the “objective quantitative study of nature,” and the progress of science would prove the effectiveness of his advice that “To perfect the mechanical arts and invent new instruments of research, it is necessary to bring into play simultaneously and along diverse ways all the measuring forces of our reason.” 

Affirming a moving Earth, elliptical orbits, the relativity of motion, extraterrestrial life, and the existence of multiple worlds, Cusa spearheaded the systematic destruction of the Aristotelian Universe that had been passed down from the ancient world. Toppling the cosmos of his Classical predecessors, Cusa—through his faith in the one Creator God—established the essential foundations for the construction of modern science.