Were the Middle Ages the cradle of Modern Science?


"It is in the Latin Middle Ages in Western Europe that we must look for answers to questions just as: Why did science as we know it today materialize only in Western society?" (Grant 170). This quote by Edward Grant, a brilliant connoisseur of medieval science, perfectly illustrates his main argument on the history of science. In his book The Foundation of Modern Science in the Middle Ages, he argues that contrary to prevailing opinion, the discoveries that culminated in the Scientific Revolution of the Seventeenth century are rooted in medieval science. By focusing on the figure of Nicole Oresme (1320-1382), a medieval thinker that dramatically reframed the philosophy of science, this essay will discuss to what extent the XVIth century can be considered as the foundation of Modern Science, which we will define as follows. "By contrast with pre- modern science, which was shaped by the Aristotelian-Thomistic paradigm, Modern science redefined the scientific method as an experimental process" (D'Hardemare 1). This definition thus brings into focus experimentalism as the key feature of modern science. Due to its historicized perspective, it will serve as the basis of this essay's discussion.

This paper will first examine the main points of the writings by Nicole Oresme that, although profoundly imbued with Aristotelian thought, challenge Aristotle's theory. Then, we will discuss the extent to which Oresme introducs the experimental process. Lastly, this essay will inquire the role of God and the Scriptures in Oresme's analysis of nature and the natural order.

Relativity: A Path to Challenge Aristotle?

Nicole Oresme challenged Aristotle's philosophy by introducing a notion that is often held to be the very core of modern science: relativity. For this reason, Nicole Oresme is often called the "Einstein of the XIVth century", as he profoundly explored the implications of relativity in terms of motion. Relativity, the idea according to which each scientific term has no absolute value, but only exists in relation with another scientific term, is the basis used by Oresme to criticize one of the pillars of the Aristotelian philosophy: the possibility of a daily axial rotation of the earth.

Oresme begins by implicitly reframing his intellectual approach as an emancipate process from Aristotle's theory, as revealed by the claim "it is good to consider the truth [...] without even considering the authority of any man but only that of pure reason" (Possibility 548). Oresme thus asserts his willingness to detach himself from any pre- established source of authority. Instrad, he construct a coherent system of thinking based on reason. In this regard, is not it striking to notice that reason, (often considered the very core value of modern science) is held by Oresme as the ultimate source of legitemacy?.

This framework being laid down, Oresme is poised to question whether or not "the earth is at the center of the universe, and that it revolves and movers circularly around the pole established for this" (Earth 600). Indeed, until the XIVth century, the collective authority of Aristotle and Ptolemy led to the "unanimous acceptance of the belief that the earth laid immobile at the center of the universe" (Grant 114). However, in his commentaries of Aristotle, Oresme introduces the idea that the rotation of the earth is possible, by reframing this question around the concept of relative motion.

To argue in favor of relative motion, Oresme describes the experience of an observer on a moving ship a, who considers himself at rest, while looking at another ship b which is in motion. Oresme explains that: "because [...] a and b are continually changing their dispositions with respect to each other [...] [it seems to a] that neither ship is moving" (Earth 601). Oresme uses this familiar experience, already mentioned by Buridan, to demonstrate that "local motion can be sensibly perceived in so far as one may perceive one body to be differently disposed with respect to another" (Earth 601).

By using an analogical reasoning, Oresme then shows that this experience of relative motion between two ships is applicable to the relative motion of the earth and the heavens. He explains that:

"Similarly, if a person were in the heavens and it were posited that they were moved with a diurnal movement [...] it would seem to him that the earth was moved with a diurnal movement [...]. Similarly, if the earth and not the heavens were moved with a diurnal movement, it would seem to us that the earth was at rest and the heavens were moved" (Earth 602).

In both of these sentences, Oresme uses the same logical structure. He begins both of the sentences with the word "similarly", implying the idea of reciprocity. Then, he rigorously shows the reversibility of the observer's experience according to its place of observation. To do so, he constructs two parallel situations that are based on the very same grammatical structure. In the first situation, the observer is in the heavens, the celestial object moved with a diurnal movement is the heavens, and the celestial object at rest is the earth. In the second situation, it is the exact opposite: the observer is on earth, the celestial object moved with a diurnal movement is the earth and the celestial object at rest is the heavens. In the first situation, it seems to the observer that the earth is moved with a diurnal movement and that heavens are at rest. In the second situation, it seems to the observer that the heavens are moved with a diurnal movement and that the earth is at rest. Based upon logic, Oresme thus demonstrates how the belief according to which the earth is immobile only relies only on a question of perspective, and furthermore, how relative motion can help to reverse this theory.

Speculation: The Foundation of the Modern Experimental Science?

To what extent can this tremendous "reconceptualization" (Kaye 6) fit into the narrative of the emergence of modern science during the XVIth century? Etienne Gilson argues that Oresme and his contemporary John Buridan "did not only emancipate [themselves] from the Aristotelian philosophy. Beginning in the XIVth century, the Middle Age also laid down the basis of modern Physics and Astronomy [...]. This is due by and large to the apparition of a new intellectual trend: experimentalism" (Gilson 124). As stated above, this essay is based on the idea that experimentalism is the key feature of modern science. But how can we define experimentalism? As a starting point, we will use the following definition: "experimentalism describes what is based on experience as opposed to authority or conjecture " (Oxford Dictionaries 3).

At the very beginning of his commentary on Aristotle, Oresme explicitly states that: "the earth [...] is moved with a daily movement [and] one could not demonstrate the contrary by any experience" (Earth 600). The notion of experiences is thus introduced as the very method to explore the question of the daily rotation of the earth. According to Pierre Duhem, a specialist of the history of science, Oresme’s questioning of the Aristotelian physics paved the way for the construction of a new kind of physics, based on experience. It is this new kind of physics that gradually led to the mathematized Physics of Copernicus. And as Professor Kaye underlines, "Copernicus used [the] identical arguments [as those used by Oresme] [...] as the conceptual basis for his "revolutionary" argument for the rotation of the earth" (Kaye 3). Although historians are not sure whether or not Copernicus did read Oresme's writings, Oresme contributed in planting the seeds for Copernicus' intellectual revolution.

It is nevertheless crucial to notice that the experiences led by Oresme are mental experiments, which he names speculations. He states himself that "speculation can be offered [which he] would like to toy with as a mental exercise" (Worlds 549). For Oresme, to speculate on counterfactual hypothesis is a valuable source speculate on counterfactual hypothesis is a valuable source in building a hypothesis. For instance, this can be seen for instance when, after describing the experience of the ships stated above, and applying it to the relation between the earth and the heavens, Oresme concludes that: "one cannot demonstrate by any experience that the heavens are moved with daily movements" (Earth 606). Oresme therefore values his speculations as reliable experiences that can be used as a legitimate source of knowledge, which is precisely what this essay has defined as the method peculiar to modern science.

Moreover, Oresme can be regarded as a scientist that significantly contributed to the establishment of modern science, as he gathers the three crucial pre-conditions identified by Grant as catalysts of the Scientific Revolution of the XVIIth century. Indeed, Oresme translated "Greco-Arabic works on science [...] into Latin" (Grant 171), notably Aristotle's Book of the Heavens and the World, which is the "first, indispensable pre- condition for the Scientific Revolution" (Grant 171). He also contributed to the development of medieval universities, as he was a teacher at the university of Paris, which is the second condition identified by Grant. Last, Oresme belonged to the "class of the theologian-natural philosophers" (Grant 174) that were "significant contributors to both natural philosophy and science" (Grant 175) that triggered the Scientific Revolution.

Is The New Form of Science Compatible With God and the Scriptures?

This last question is that of the relations between this new form of science, resolutely modern, and God and the Scriptures. Indeed, modernity is often associated with a set of beliefs that distances itself from religion. However, in Oresme's writings, we read a much more complex relation to the Divine.

First, let us notice the very paradoxical effect of the Condemnations of 1277. These condemnations prohibited 219 propositions inspired by the Aristotelian-Averroist paradigm, in order to reaffirm the infinite Providence of God. However, this did not restrict the field of scientific thought. On the contrary, by affirming the unlimited power of God, the Church actually enabled the "theologian-natural philosophers" (Grant 174) to extend the scope of their hypothesis. Indeed, by stating the principle according to which God can build any cosmological configuration, the theologian-natural philosophers were actually able to freely build any kind of hypothesis.

Oresme uses the infinite power of God's and its ability to create anything to "speculate about the possibility of several worlds" (Worlds 550). He explains that one way to do so is to think of a world "entirely outside [our world] in an imagined space" (Worlds 550). To demonstrate that this is possible, he begins by stating the counter- argument derived from the Aristotelian Physics: "if several worlds existed, it would follow that the earth in the other world would tend to be moved to the center of our world and conversely" (Worlds 550). However, he argues that "beyond [...] heavens there is no up or down" (Worlds 550), and therefore concludes that: "if God created a portion of earth and set it in the heavens [...] this earth would have no tendency to be moved towards the center of our world" (Worlds 550). The very basis of Oresme's argument is not legitimatized by God, but rather by the dissociation between the weight of a body and its potential motion: "a heavy body to which no light is attached would not move itself"

(Worlds 551). However, the possibility of Oresme's relies on the power of God to "create a portion of earth and set it in the heavens" (Worlds 550), and it is only under this assumption that Oresme is able to discuss the possibility of a world existing outside ours. Witness his conclusion of this hypothesis: "it cannot happen in this way naturally, although God could do it and could have done it in the past by His own omnipotence" (Worlds 551).


The figure of Nicole Oresme embodies the transition from pre-modern to modern science, for he represents the "rise of relativistic thought," (Kaye 4) and experimenting lies at the core of his intellectual approach. However, let us recall that relativistic thinking is not the product of a single man, but that of an entire "living culture" (Kaye 7). We must understand the increased importance of relativity within the economic context of the XIIIth and the XIVth centuries. Indeed, during this period, the "marketplace continu[ally] increase[d] in power" (Kaye 7), and thus implemented a "relative order" (Kaye 7) that progressively undermined the "graded order of Christian nature" (Kaye 7).

Therefore, one must not overestimate the direct influence of Oresme and his contemporaries on the Scientific Revolution of the XVIIth Century, but rather understand that Oresme contributed to translate relativity "into scienfic speculation" (Kaye 8), which, in the long-run "revolutionized the [scientific] world" (Kaye 8).

© Rosalie Calvet, October 2015

Works Cited

“Experimental” Oxford Dictionaries Nov. 19th 2015: 3. <http://www.oxforddictionaries.com/definition/english/experimental>

D'Hardemare, Adrien. “Qu'est-ce que la science moderne?” Encyclopédie Chrétienne Nov. 19th 2015: 1-2. Theopodemie.com < http://theopedie.com/Qu-est-ce-que-la- science-moderne.html >.

Kaye, Joel. “Power of Relative thinking.” Barnard College, Columbia University April 2000: 1-8.

Gilson, Etienne. La Philosophie au Moyen Âge, vol.II : de saint Thomas d’Aquin à Guillaume d’Occam. Payot, 1922.

Grant, Edward. The Foundations of Modern Science in the Middle Ages Oct 1996, Cambridge Press: Chap 6 and Chap 8, 104-176.

Oresme, Nicole. Speculations on the possibility of the Earth's Daily Axial Rotation Oresme, Nicole, On the possibility of a plurality of Worlds