How Christianity Created Modern Science

(c) 2009 by Barton Paul Levenson


If I had seen an article with a title like this in my atheist days, I would have been very skeptical. After all, didn't science arise in ancient Greece, the Middle East, and China?

Yes it did, in those three places, and in medieval Europe. And in the first three places, it died without getting anywhere. The only place the scientific revolution succeeded was in Christian Europe of the high middle ages. Why was that?

I maintain that it was because of Christian religious doctrine that science succeeded in Europe--and because of the lack of it that it failed elsewhere.

Epistemological Prerequisites for Science
(or, "how you have to think about things to get science done")

I'd say that, in order to spend time on science and use it effectively, you need to start with these premises:

  1. The universe (nature) is real.
  2. The universe is worth learning about.
  3. The universe operates according to fixed laws; it is not capricious and ultimately unpredictable.
  4. Human senses and instrument readings, aside from special cases like hallucination or instrument error, give reliable information about the universe.
  5. Reason (formal logic) can be applied to sensory data to give reliable results.

How Christianity Supports these Premises

The Christian philosophers of the middle ages, working from the Bible and from rational arguments on behalf of Christianity such as those provided by St. Augustine and Thomas Aquinas, came up with certain doctrines about the natural world:

  1. The reality and goodness of creation. The world is real and it is a good thing. It is not an illusion.
  2. Secondary causation. God, the ultimate lawgiver, gave Nature laws to operate by which can be discovered by human intelligence. Nature is capable of bringing events to pass on its own. Natural causes have natural results. God does not have to intervene directly for natural causation to operate.
  3. Vocation. All forms of work are honorable.

Let me give some examples of the expression of these beliefs in Christian teaching.

The reality and goodness of creation

Genesis 1:4 And God saw the light, that it was good: and God divided the light from the darkness. ... 10 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good. ... 12 And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good. ... 18 And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good. ... 21 And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good. ... 25 And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good. ... 31 And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.
"The opinion of those who say with regard to the truth of faith that it is a matter of complete indifference what one thinks about creation, provided one has a true interpretation of God... is notoriously false. For an error about creation is reflected in a false opinion about God."
-St. Thomas Aquinas

Secondary causation

Genesis 1:11 And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so. ... 20 And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven. ... 24 And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.
"In studying nature we have not to inquire how God the Creator may, as He freely wills, use His creatures to work miracles and thereby show forth His power; we have rather to inquire what Nature with its immanent causes can naturally bring to pass."
-Albertus Magnus, De Vegetabilibus et Plantis
"[God] is the author of all things, evil excepted. But the natures with which He endowed His creatures accomplish a whole scheme of operations, and these too turn to His glory since it is He who created these very natures."
-William of Conches
"I propose here to show the causes of some effects which seem to be miracles and to show that the effects occur naturally There is no reason to take recourse to the heavens [astrology], the last refuge of the weak, or to demons, or to our glorious God, as if he would produce these effects directly "
-Nicholas d'Oresme, Bishop of Lisieux, De Causa Mirabilium
"The situation [God creating the heavens and establishing their regular motions] is much like that of a man making a clock and letting it run and continue its own motion by itself so that all the wheels move as harmoniously as possible."
-Nicholas d'Oresme, Bishop of Lisieux, Livre du Ciel et du Monde


Genesis 2:15 And the LORD God took the man, and put him into the garden of Eden to dress it and to keep it.
Ephesians 4:1 I therefore, the prisoner of the Lord, beseech you that ye walk worthy of the vocation wherewith ye are called...
Ephesians 4:28 Let him that stole steal no more: but rather let him labour, working with his hands the thing which is good, that he may have to give to him that needeth.
2 Thessalonians 3:8 Neither did we eat any man's bread for nought; but wrought with labour and travail night and day, that we might not be chargeable to any of you: 9 Not because we have not power, but to make ourselves an ensample unto you to follow us. 10 For even when we were with you, this we commanded you, that if any would not work, neither should he eat. 11 For we hear that there are some which walk among you disorderly, working not at all, but are busybodies. 12 Now them that are such we command and exhort by our Lord Jesus Christ, that with quietness they work, and eat their own bread.
"Labora est ora" (Work is prayer).
-Motto of the Benedictines

Why the Scientific Revolution Failed in Ancient Greece

Greek science depended on the use of pure reason rather than the examination of empirical evidence. Although Aristotle formulated the doctrine, "There is nothing in the intellect that was not first in the senses," he didn't consistently follow through in his own investigations. He insisted, for example, that men had more teeth than women, "By reason of the abundance of heat and blood which is more in men than in women." Bertrand Russell suggested that, although Aristotle was married twice, he never thought to check his wives' mouths. This may or may not be true. He might have checked women who happened to have fewer teeth than the men he checked. He wouldn't have been misled by missing wisdom teeth because he knew about that physiological process. But for whatever reason, he put the rational concept, men have a greater abundance of heat and blood, ahead of the observations. It stood to reason that men should have more teeth, therefore they did. Ultimately, reason took precedence over evidence. And the reason for this was that field investigation was manual labor, and manual labor was fit only for slaves. Gentlemen did not work with their hands. Collecting observations in the field is working with your hands. We can read between the lines of Aristotle's many works on scientific subjects to infer that he did, in fact, do a fair amount of field work, but he never openly admitted it. He was ashamed of it.

"Where then there is such a difference as that between soul and body, or between men and animals (as in the case of those whose business is to use their body, and who can do nothing better), the lower sort are by nature slaves, and it is better for them as for all inferiors that they should be under the rule of a master. For he who can be, and therefore is, another's and he who participates in rational principle enough to apprehend, but not to have, such a principle, is a slave by nature. Whereas the lower animals cannot even apprehend a principle; they obey their instincts. And indeed the use made of slaves and of tame animals is not very different; for both with their bodies minister to the needs of life. Nature would like to distinguish between the bodies of freemen and slaves, making the one strong for servile labor, the other upright, and although useless for such services, useful for political life in the arts both of war and peace. But the opposite often happens--that some have the souls and others have the bodies of freemen. And doubtless if men differed from one another in the mere forms of their bodies as much as the statues of the Gods do from men, all would acknowledge that the inferior class should be slaves of the superior. And if this is true of the body, how much more just that a similar distinction should exist in the soul? but the beauty of the body is seen, whereas the beauty of the soul is not seen. It is clear, then, that some men are by nature free, and others slaves, and that for these latter slavery is both expedient and right."
-Aristotle, Politics

In short, the Greek philosophers rejected the idea of vocation. Science was a pursuit for intellectuals who had time on their hands because they had slaves to do their work for them. It wasn't a profession. And it wasn't supposed to have practical applications.

Why the Scientific Revolution Failed in the Caliphate

Arab scientists did sterling work during the dark ages, especially in astronomy and chemistry, but the scientific revolution failed again in the medieval Middle East. And it failed as the result of a clear debate which the empiricists lost. In the ideas of the school that won, natural law and causation did not exist!

Islamic philosophers (mutakallimun) believed that "when a man moves a pen, it is not the man who moves it; for the motion occurring in the pen is an accident created by God in the pen. Similarly the motion of the hand, which we think of as moving the pen, is an accident created by God in the moving hand. Only God has instituted the habit that the motion of the hand is concomitant with the motion of the pen, without the hand exercising in any respect an influence on, or being causative in regard to, the motion of the pen."
-Moses Maimonides, Guide to the Perplexed
"[H]e who studies or teaches philosophy will be abandoned by God's favor, and Satan will overpower him. What field of learning could be more despicable than one that blinds those who cultivate it and darkens their hearts against the prophetic teaching of Muhammed?"
-Ibn as-Salah ash-Shahrazuri
"[A]ll those who give evidence of pursuing the teachings of philosophy must be confronted with the following alternatives: either [execution] by the sword or [conversion to] Islam, so that the land may be protected and the traces of those people and their sciences may be eradicated."
-Ibn as-Salah ash-Shahrazuri

Al Ghazali and ibn Khaldun spoke similarly. And their side won. Al-Kindi, an Arab scientist and one of the five great muslim faylasuf ("philosophers"), was protected by the first two caliphs he worked for, but the third confiscated his personal library and gave the 60-year old philosopher fifty lashes in a public flogging. Eyewitnesses report that the crowd roared with approval at each stroke. Ibn Rudh, an even greater scientist, was thrown out of office and exiled from Marrakesh. The Scientific Revolution was violently and deliberately aborted in the Islamic world.

Why the Scientific Revolution Failed in Medieval China

Chinese religion and philosophy were dominated by Buddhism, a religion which maintains that the world of the senses is maya ("illusion"), and Confucianism, which locates right behavior in personal cultivation as a gentleman. Chinese scientists made great strides in the middle ages, but again the Scientific Revolution never took hold. The transition was one of outlook.

In the 12th century, the great empiricist Zhu Xi (1130-1200) dominated the world of philosophy. Zhu stressed the importance of gewu--investigation, field work. He argued for the importance of pattern (li) in addition to substance (qi), a development parallel to the idea of natural law in the west. He believed that there was an ordering intelligence behind the universe, akin to the god of Deism, but that the universe itself had no mind of its own, but existed only to produce things.

Zhu's devotion to empiricism was shown by an incident involving botany. A monk, following the teaching of the 3rd century BC philosopher Meng Ke ("Mencius") that qi was more vital at night, maintained that bean sprouts grew faster by night than by day. Zhu promptly measured the growth of several bean plants after twelve hours of daylight and twelve of nocturnal darkness, and found that they showed the same growth rate day and night.

But Zhu's outlook came to be replaced by that of another great Chinese philosopher, Wang Yangming (1472-1529). Wang rejected empiricism after an attempt to divine botanical principles by observing a field of bamboo:

"From morning till night I was unable to find the principles of the bamboo. On the seventh day I also became sick because I thought too hard. In consequence we sighed to each other and said it was impossible to be a sage or worthy, for we do not have the tremendous energy to investigate things [for the principles] that they have. After I had lived among barbarian peoples for three years, I understood what all this meant and realized that there is really nothing in the things in the world to investigate, that the effort to investigate things is only to be carried out in and with reference to one's body and mind, and that if one firmly believes that everyone can become a sage, one will naturally be able to take up the task."
-Wang Yangming, Chuanxi Lu ("Instructions for Practical Living"). Recorded by students 1521-1527.

In short, you learned by introspection, not by observing nature. China accepted Yang's outlook and the scientific revolution in China died on the vine.


Ideas matter. They affect how people think and how they act. The worldview of Christian medieval Europe, with its doctrines of natural law, secondary causation, and vocation, set the stage for the scientific revolution. The first great scientists in Christian Europe were all church officials--Jean Buridan, who formulated the first law of motion 300 years before Newton; Nicholas d'Oresme, who derived the mean speed theorem; Albert of Saxony, who calculated what free-fall velocity would be in a vacuum; Theodoric of Fribourg, who explained the rainbow optically; Copernicus, who developed heliocentric astronomy; Nicholas of Cusa, who speculated on an infinite universe and extrasolar planets, etc., etc.

In our society, when we think of science and the medieval church, we usually think of Galileo--the one real example of the church suppressing a scientist over a scientific doctrine* (though one could say the main reason Galileo was suppressed was that he couldn't refrain from insulting the hell out of his feudal superiors). The treatment of Galileo was indeed a black mark on church history, but the story has succeeded in concealing the much more important role Christian theology had in permitting and setting in motion the modern scientific revolution in the first place.

Incidentally, I hope this discussion makes clear that "scientific creationism" is, if not openly heretical, at least skirting the fine edges of heresy. If you say God had to create everything in nature by divine special creation, and that natural causes can't be bringing about, say, speciation, throughout geological history and even right now, you're pretty much denying the doctrine of secondary causation. You're saying God has to micromanage creation in each event. If that philosophy were to take hold, in the US or elsewhere, it would ultimately kill science. Natural law is the opposite of divine intervention. God has to set natural law aside, or at least feed a new event into the pattern, every time he performs a miracle--and miracles must, by definition, be rare, or no one would recognize them as miracles. So that's one more reason, besides my scientific education, why I have to reject creationism. For me, it fails not only on scientific grounds, but on theological grounds as well.

*Giordano Bruno is sometimes called a "martyr of science," burned at the stake for believing in an infinite universe and extraterrestrial life. "Belief in the plurality of worlds and in their eternity" was indeed one of the eight counts against Bruno. But why is a mystery, since Nicholas of Cusa had discussed the universe being infinite 200 years earlier without getting into trouble, and every educated person in midieval Europe believed there was intelligent life on the other planets, the sun, and the moon. Perhaps the "eternity" bit was seen as a swipe at the doctrine of Creation. But the other seven counts of the indictment were all about Bruno's views on God, Christ, the Virgin Mary, etc. The most serious charge against Bruno, and very likely the one that got him executed (after the Roman inquisition tried for eight years to get him to recant) was his charge that Christ was not divine but was a "magician."

Page created:07/13/2009
Last modified:  02/01/2011