Science & Culture

Theism and Science Inextricably Conjoined

As exemplified by our list in the Franciscan Scientific and Intellectual Tradition, there are numerous devout Catholic scientists who are theists: they conceive of God as personal, present, and active in the governance and organization of the world and the universe. An issue of fundamental interest is about a deeper relationship. How are theism and science inextricably joined in the work of certain scientifically productive individuals? We briefly review the examples of René Descartes, Gottfried Leibniz, and Francis S. Collins.

René Descartes 
René Descartes (Renatus Cartesius, 1596–1650), often referred to as the founder of modern Western philosophy, was also an extraordinary mathematician and 

scientist. While the validity of his theories is outside our purpose, Descartes’ life and thought are illustrative. Descartes is a scientist who can not be genuinely understood by separating his science and his philosophy from his faith. As a 

thinker who conjoins science and theism, of considerable interest are:

• The nature of Descartes’ philosophic, scientific, and religious writings
• Certain problems that he faced as a result of the Catholic church’s seventeenth-century position toward Galileo

• His lifelong friendship and exchanges with Franciscan Marin Mersenne (1588–1648), a   friar of the Order of Minims/Orden de Mínimos.

At the age of 23, on the night of 10–11 November 1619, Descartes had an epiphany in the form of three dreams that transformed his life and made a lasting contribution to science, mathematics, and the methodology of inquiry.

Serving in the army of Maximilian, the young French soldier was waiting out the winter of 1619–1620 in the small Bavarian village of Ulm and trying to keep warm. He refers to the period generally in his famous Discourse on the Method of Rightly Conducting One’s Reason and of Seeking Truth in the Sciences, but he wrote an account immediately after the experience, which was lost in the late seventeenth century but is closely paraphrased by his first biographer, Adrien Baillet, in 1691. For weeks he had been in a state of intense concentration and agitation, seeking answers to profound problems that he had been struggling with. This so exhausted him that his brain “took fire.” He fell into a state of “enthusiasm” (in the archaic sense from the Greek entheos, a state of supernatural frenzy.) That night, exhausted, he had the three dreams mentioned above.

In the first dream, Descartes, frightened by phantoms, attempted to flee through the streets of a city. He felt a “great weakness” on his right side and was forced to bend to his left. Ashamed, he tried to straighten up but was carried off in a whirlwind that spun him around. Then Descartes saw a school ahead and searched for the chapel in order to pray for divine assistance. He found the chapel but realized that in his fright he had “passed an acquaintance without greeting him.” He turned to go back but was thrown against the wall of the chapel by high winds. Another man stood before him in the school courtyard. He told Descartes that a Monsieur N. had a gift for him. Descartes imagined the gift was “a melon from a foreign land.” The wind abated, and Descartes noticed that others in the courtyard were standing normally while he was still bent. Descartes woke with pain on his left side. He feared the dream was the work of “some Evil Spirit who had wanted to seduce him,” and he prayed for God’s protection, acknowledging that his own sins were enough to “call down upon his head thunderbolts of heaven.”

Falling back asleep, in his second dream he heard the crack of thunder. Waking again in terror, he saw “sparks of fire” around him in his room. Now he responded analytically. He had had this experience of seeing sparks on waking before, and he was able to reassure himself by observing the phenomenon carefully and seeking an explanation in natural philosophy. According to Baillet, “He fell asleep again quite calmly.”

Soon after, he had his third dream. Baillet tells us that it was not “frightful” and Descartes found it “very soothing.” Descartes found a book mysteriously placed on his table. He discovered that it was a dictionary, and at the same moment he found a second book before him, this one a collection of poetry titled Corpus Poetarum. Opening this second book, he found the line: Quod vitae sectabor iter? (What road of life shall I follow?). He looked up to find a stranger before him; the man gave him yet another poem, this one on a separate page that began: Est et Non (It is and is not). The visitor urged him to read it, and Descartes replied that he in fact knew the poem already; it was a poem by Ausonius in the Corpus Poetarum that he had just found on the table. Descartes even “boasted” of knowing the “order and scheme” of the Corpus “perfectly,” and reopened the book to find the passage for the stranger. As he searched, the man asked where the Corpus had come from. Descartes did not know, but told the visitor that it had appeared on his table with another book, which Descartes now noticed had disappeared. At that moment the dictionary reappeared at the far end of his table, and Descartes, still paging through the Corpus in his search for Est et Non, noted that the dictionary, while returned, was no longer as complete as the version that had first appeared.

Descartes finally found the poems of Ausonius in the Corpus, but still could not locate the verse opening with Est et Non. Instead he promised the visitor an even better poem by Ausonius, one that began with the line Quod vitae sectabor iter? The visitor begged to see the poem, and Descartes continued his search. But as he did, his attention was drawn by “several little portraits engraved by copperplate,” which he found “very handsome.” He realized that this was not the edition of the Corpus with which he was familiar. At the moment of that realization, the stranger and the two books disappeared.

Initially, Descartes was bewildered and began to pray. He assumed his dreams had a supernatural origin. He vowed he would put his life under the protection of the Blessed Virgin and go on a pilgrimage from Venice to Notre Dame de Lorette, traveling by foot and wearing the humblest clothes he could find.

However, soon the dream propelled him on a mission. He interpreted his dream as a revelation. “It was the Spirit of Truth that willed to open for him all the treasures of knowledge.” Descartes deciphered the key elements of his dreams, particularly the third one. The dictionary stood for “all the Sciences gathered together.” The Corpus Poetarum meant “the union of Philosophy and Wisdom.” Quod vitae sectabor iter? “represented the good advice of a wise person or even of Moral Theology.” Est et Non, the poem offered to him by the stranger “he understood [as] Truth and Falsehood in human understanding and the profane sciences.” Finally, the wind that propelled him toward the chapel in the initial dream, Baillet records, “was nothing other than the Evil Spirit who was trying to throw him by force into a place that he intended to enter by his own free will.”

Descartes came to the life-changing judgment that his dreams of that night pointed to no less than the unification and the illumination of the whole of science, even the whole of knowledge, by one and the same method: reason.

Eighteen years later Descartes had worked out the details of his providential epiphany and of the “mirabilis sientiae fundamenta,” the foundations of a marvelous science. They are contained in his essay Discourse on the Method of Rightly Conducting One’s Reason and of Seeking Truth in the Sciences. According to Descartes, his “method” should be applied when knowledge is sought in any scientific field. It consists of (a) accepting only what is so clear in one’s own mind as to exclude any doubt, (b) splitting large difficulties into smaller one, (c) arguing from the simple to the complex, and (d) checking wh

en one is done. It is instructive to observe that in this six-chapter essay, the first three are autobiographical in nature. This was no dry treatise!

Descartes’ point of departure is: What can be known if all else is doubted? He has come to the point of his famous, “I think therefore I am.” What has been customarily omitted in the last century is that Descartes’ next step was to establish the near certainty of the existence of God by means of the following notion: Only if God both exists and would not want us to be deceived by our experiences can we trust our senses and logical thought processes. God is central to Descartes’ entire philosophy and to his science. The results were bountiful. Descartes’ famous advances include the following:

• He made a key connection between geometry and algebra that permitted the solving of geometric problems through algebraic equations and led to the establishment of calculus by Isaac Newton and analytic geometry by Leibniz in the generation that followed him.

• He conceived of matter in a new way that allowed for the accounting of physical phenomena by way of mechanical explanations.

• He wrote the Meditationes de prima philosophia, in qua Dei existentia et animæ immortalitas demonstratur (Meditations on First Philosophy: In Which the Exisence of God and the Immortality of the Soul are Demonstrated, 1641), which provides a philosophical groundwork for the possibility of the sciences.

Even as he was a lifelong Catholic of profound faith, Descartes’ life and work were affected by the Church’s condemnation of Galileo (1564–1642). He had prepared a work entitled The World, which was ready for publication in 1633. Upon hearing of the Church’s condemnation of Galileo in the same year, Descartes decided against its publication. The world system he had adopted in his book assumed, as did Galileo’s, the heliocentric Copernican model. In a letter to Marin Mersenne dated November 1633, Descartes expresses his fear that were he to publish The World, the same fate that befell Galileo would befall him. The World appears to have consisted of several smaller but related works on physics, mechanics, animals, and man.

Père Marin Mersenne, theologian, philosopher, mathematician, and music theorist who is often referred to as the “father of acoustics,” was a longtime friend of Descartes beginning when they were students. Mersenne joined the Minim Friars in 1611 and he was a foremost scientist of his time. He was a staunch defender of Galileo, assisting him in translations of some of his mechanical works. He also was Descartes’ confidante and his adviser. They had a lifelong productive relationship, and numerous letters between them exist. Mersenne defended Descartes, who was the subject of vehement attacks for his Meditationes de prima philosophia. Mersenne asked that, after his death, an autopsy be made on his body so as to serve to the last the interests of science.

Is Descartes perchance the odd case? Does Descartes represent the singularity of a thinker for whom God was central to his life and work? Hardly! In the following generation, we have the great mathematician and scientist, Leibniz.

Gottfried Leibniz 
Gottfried Leibniz (1646–1716), often known as the last “universal genius,” devoted considerable effort to ecumenism. He strove to reunite first his Lutheran Church with the Roman Catholic Church and later the Lutheran and Reformed Churches. He judged that the application of reason could heal the breach caused 

by the Reformation. He also tried to reconcile thinkers like René Descartes and Thomas Hobbes.

Leibniz developed a set of fundamental philosophic principles from which he developed his philosophy. For our purposes, the following are key:

• Sufficient reason. “There must be a sufficient reason, often known only to God, for anything to exist, for any event to occur, for any truth to obtain.”

• Optimism. “God assuredly always chooses the best.” (Optimism does not refer to a mood but to optimalization).

• Plenitude. The best of all possible worlds actualizes every genuine possibility. In Théodicée (The Theodicy) he states that this best of all possible worlds will contain all possibilities, with our finite experience of eternity giving no reason to dispute nature’s perfection.

• Pre-established harmony. “[T]he appropriate nature of each substance explains that what happens to one corresponds to what happens to all the others, without, however, their acting upon one another directly.” (Discourse on Metaphysics, XIV) A dropped glass shatters because it “knows” it has hit the ground, and not  because the impact with the ground “compels” the glass to split.

Pre-established harmony underpins Leibniz’s noted contribution to metaphysics: his theory of monads, as exposited in Monadologie. Monads, comparable to the corpuscles of the Mechanical Philosophy of René Descartes, are the ultimate elements of the universe. Monads are “substantial forms of being” with the following properties: they are eternal, indecomposable, individual, subject to their own laws, un-interacting, and each reflecting the entire universe in a pre-established harmony. The ontological essence of a monad is its irreducible simplicity. Unlike atoms, monads possess no material or spatial character. They also differ from atoms by their complete mutual independence, so that interactions among monads are only apparent. 

Instead, by virtue of the principle of pre-established harmony, each monad follows a preprogrammed set of "instructions” peculiar to itself, so that a monad “knows” what to do at each moment. God, too, is a monad, as are humans, and the existence of God is inferred from the harmony among all other monads; God wills the pre-established harmony. Monads function to resolve the problem of the interaction between mind and matter in Descartes system and the lack of individuation in the system of Spinoza which represents individual creatures as merely accidental.

In mathematics, Leibniz greatest achievement was his independent discovery of differential and integral calculus, also simultaneously invented by Isaac Newton. Modern calculus follows the notations and conventions of Leibniz, not Newton. In physics, Leibniz proposed the use of “dynamics” or kinetic energy to explain motion, rather than “mechanics” that is based on Cartesian coordinates. Leibniz held the view that light always traveled the path of least resistance.

Leibniz asserted that the truths of theology and philosophy cannot contradict each other, since reason and faith are both “gifts of God” so that their conflict would imply God contending against himself. Because reason and faith must be entirely reconciled, any tenet of faith which could not be defended by reason must be rejected. Leibniz considered one of the central criticisms of Christian theism to be as follows: if God is all good, all wise, and all-powerful, how did evil come into the world? Leibniz’s answer is that, while God is indeed unlimited in wisdom and power, his human creations are limited both in their wisdom and in their power to act. This predisposes humans to false beliefs, wrong decisions and ineffective actions in the exercise of their free will. God does not arbitrarily inflict pain and suffering on humans; rather he permits both moral evil (sin) and physical evil (pain and suffering) as the necessary consequences of metaphysical evil (imperfection), as a means by which humans can identify and correct their erroneous decisions. Although human actions flow from prior causes that ultimately arise in God, and therefore are known as a metaphysical certainty to God, an individual’s free will is exercised within natural laws, where choices are merely contingently necessary, to be decided in the event by a “wonderful spontaneity” that provides individuals an escape from predestination.

Francis S. Collins
In this century, Francis S. Collins (born 1950), is another example of a scientist whose work is nourished by theism. With a Ph.D. in Physical Chemistry (Yale) and an M.D. (North Carolina, Chapel Hill), this American physician-geneticist, noted for his landmark discoveries of disease genes and his leadership of the Human Genome Project (HGP), is currently Director of the National Institutes of Health (NIH) in Bethesda, Maryland.


Collins, originally “a casual agnostic” with only a nominal Christian upbringing, converted to Catholicism as the result of his interaction with dying patients which led him to question his religious views, and to investigating various faiths. He familiarized himself with the evidence for and against God in cosmology, and used Mere Christianity by C. S. Lewis as a foundation to reexamine his religious views. Ultimately, he became an evangelical Christian.
In his 2006 book The Language of God: A Scientist Presents Evidence for Belief, Collins considers scientific discoveries an “opportunity to worship.” In his book, Collins examines and subsequently rejects Young Earth creationism and intelligent design. His belief system is theistic evolution or evolutionary creation, which he calls BioLogos.

In 2009, Collins founded the BioLogos Foundation to “contribute to the public voice that represents the harmony of science and faith.” He served as the foundation’s president until he was confirmed as director of the NIH. On October 14, 2009, Pope Benedict XVI appointed Francis Collins to the Pontifical Academy of Sciences. Collins actively publishes on the topic of theism and science and his work includes the following:

• The Language of God: A Scientist Presents Evidence for Belief. New York: Free Press, 2006, which spent many weeks on the New York Times bestseller list.

• The Language of Life: DNA and the Revolution in Personalized Medicine. New York: HarperCollins, 2010.

• Belief: Readings on the Reason for Faith. New York: HarperOne, 2010.

• The Language of Science and Faith: Straight Answers to Genuine Question. With Karl Giberson. Nottingham, UK: Inter-Varsity Press, 2011.

Bibliographic Notes on Descartes’ Three Dreams 
Descartes dreams, critical as they are, have been the source of much comment and speculation. A brief bibliographic aid follows.

The three dreams appeared originally in the Olympica section (lines 35-36) of the “Little Notebook,” a collection of Descartes early occsional writings.

The “Little Notebook,” was lost in the late seventeenth century. However, a closely paraphrased translation of the “Little Notebook” was made by Descartes first biographer, Adrien Baillet in his book, La vie de Monsieur Descartes (1691). This printed book can be viewed online and also downloaded as a pdf at the following website on Gallica, the digital library of the Bibliothèque nationale de France:

It is also republished in Charles Adam and Paul Tannery’s Oeuvres de Descartes (Paris, multiple volumes between 1901-1908). An English translation, working from both the Baillet biography and the Adam and Tannery republication, appears in John R. Cole, The Olympian Dreams and Youthful Rebellion of Rene Descartes (Urbana and Chicago: University of Illinois Press, 1992).

Additional valuable references are:

Bordo, Susan R. The Flight to Objectivity: Essays on Cartesianism and Culture (Albany: State University of New York Press, 1987).

Challenger, Donald. “Somnio Ergo Sum.” Online. Accessed 11 June 2011.

Gaukroger, Stephen. Descartes: An Intellectual Biography (Oxford: The Clarendon Press, 1995).

Maritain, Jacques. The Dream of Descartes, trans. Mabelle Andison (New York, 1945).

Image Captions (from top to bottom)
No. 1: Portrait of René Descartes. Modified by Brandon Ortega. Source:
No. 2: Adrien Baillet’s La vie de Monseiur Descartes. Source:
No. 3: Cover of Decartes’ the Discourse on Method. Source:
No. 4: Statue of Rene Descartes in Tours, Loire Valley, France. Source: 
No. 5: Portrait of Marin Mersenne done by Philippe de Champaigne (1602–1674). Source: 
No 6: Portrait of Gottfried Liebniz done by Christoph Bernhard Francke. Source: No 7: A page from Liebniz’s Monadologie manuscript. Source: 
No. 8a: Francis Collins and Kathleen Sebelius after his swearing in as director of the National Institute for Health. Source: 
No. 8b: Francis Collins on a motorcycle. Source: 

No. 9: Cover of Francis S. Collins’ book The Language of God. Source: