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History of Science Roman - Pantheon

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LibraryThing: Science in Ancient Mesopotamia Week 6: Roman Science

Basil the Great, ca. 330 - 379 A.D.; and John Philoponos, 6th century A.D.

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Who was Basil?

Studying in Constantinople (346-351 AD) and Athens (351-356 AD), Basil received the best education of the day in natural history, medicine and mathematics. In 358 he entered a monastic order; he was ordained as a priest in 364. In 368, Basil led monastic efforts to sustain the poor during a famine in Asia Minor. Two years later he became the Bishop of Caesarea in Cappadocia (southeastern Asia Minor). While Bishop, he wrote a commentary on the six days of creation, as told in Genesis 1. Such commentaries on the creation week, known as hexamera, comprised a genre of encyclopedic writing on natural knowledge that remained extremely popular into the 17th century, with Basil's Hexameron providing one of the most widely read examples.

Newton, Principia (1726), title page.Through his Hexameron Basil became one of the most influential of the "church fathers" in articulating a Christian perspective on science and natural knowledge. Basil wrote in Greek, because he lived in the eastern part of the Roman empire. Yet almost immediately, Basil's Hexameron became known in the Latin speaking western half of the Roman empire. In Milan, Italy (which became a center of Latin learning in the late Roman empire while the emperor resided there instead of in Rome), Ambrose included translated portions of Basil in his own hexameral commentary. Shortly afterward, around 440 AD, Basil's entire Hexameron was translated into Latin, and it was used by Augustine and others. In the eastern, Greek-speaking portion of the Roman empire, Basil's Hexameron remained widely read, influencing, for example, John Philoponos in Athens in the 6th century and the Syriac hexameral tradition. Basil was quoted extensively through the medieval and early modern periods, from the Hexameron of Robert Grosseteste in the 12th century to the writings of Merin Mersenne and Isaac Newton in the 17th century (right).

Service to the poor: the earliest public hospital

Basil is important to the history of science for the history of medicine as well. Personally, Basil preferred the study of medicine to the mathematical sciences because health care complemented his ideals of religious service. About 372, as Bishop of Caesarea, Basil established the earliest known hospital that remained continuously open to the public, not just for the wealthy. As in the case of his earlier relief work for the poor during the famine of 369, Basil saw no contradiction between the use of natural medicines and his faith in a God who heals, emphasizing rather the obligation of those with religious faith to extend charity to the poor and needy. (Source: Gregory of Nanzianus, Oration 43.)

After a brief note on terms, the following headings contain very short quotations from Basil's Hexameron to illustrate several aspects of his perspective on nature and how nature is known. This page is relatively long, so you might want to print it out.

Note on terms: Three views of reality

We have already defined the "divine" as "That on which all else depends, but which is not dependent upon anything else (i.e., it is self-sufficient)." We have explored the early attempts by the presocratic natural philosophers to identify some kind of divine element as the cause of all things, and we have touched on Plato's understanding of Forms, and Aristotle's search for the "natures" of things that cause them to change in an orderly fashion. For the purpose of this course, we will use the term "pagan" to refer to any understanding of reality that conceives the divine as a part of nature, or as contained within nature. The term pagan in this sense is not at all intended to be pejorative, and it is one of the most common views today. We use it simply as an analytical term because it provides a useful way to contrast these views with theism and pantheism. In theism, the divine is something other than nature, something that sustains nature but that also goes beyond nature. Pantheism, which we will encounter later in the course, is the view of reality that sees nature as a part of the divine, contained within the divine. All three views contributed in important ways to the development of science. All three terms are heuristic only; in actual practice, their overlaps are complex and interesting. These terms for three different views of reality are summarized in the image below.

Monotheism: Nature as Created

Newton, Principia (1726), p. 528.Using the above terms, then, the Presocratics, Plato and Aristotle and many Romans such as Cicero, Ptolemy and Galen all conceived the divine as something inherent within the physical world (paganism). Basil, in contrast, represents an emerging theistic perspective of nature, where nature became understood as created by a divine being that transcends the creation.

For Basil, as for monotheists of Hebrew, Christian or Islamic persuasion, the order of nature ultimately derived not from a divine element or "nature" within the created thing, but from the power and purpose of a Creator who stands outside of nature and causes all things to be. This is the meaning of Basil's repeated references to God as Pantokrater, or "ruler of the universe," a phrase that was repeated by Newton in his Principia, as we will see in a future week when we read Newton's "General Scholium." (Click the thumbnail on the right to view a page from the third edition of Newton's Principia; cf. the Greek word in the third line from the top.)

Natural Law

One of the most important ideas for Basil's theistic perspective on creation was natural law. For Basil, natural laws are the effect of the omnipotent Lawgiver, who freely decreed them at the creation. When commenting on the passage in Genesis 1 where the text reads, "Let the earth bring forth...", Basil explained:

"This brief command became immediately mighty nature and an elaborate system which brought to perfection more swiftly than our thought the countless properties of plants. That command, which even yet is inherent in the earth, impels it in the course of each year to exert all the power it has for the generation of herbs, seeds, and trees. For, just as tops, from the first impulse given to them, produce successive whirls when they are spun, so also the order of nature, having received its beginning from that first command, continues to all time thereafter, until it shall reach the common consummation of all things." Basil Hexameron, Homily 5, p. 82; see also Homily 9, pp. 136-137.

For a monotheist like Basil, the natural order is the expression of a creative decree, or divine law, that remains perpetually in force because of the omnipotent power of the Creator. There is no need to identify miracles to see the handiwork of God, since God works also through natural causes. That is, there is no exclusive contrast between what is produced by "natural" causes and what is effected directly by the Creator, since the natural laws themselves represent the work of the Creator. The words that once spoke nature into being, now continue in their efficacy as the "laws of nature" governing all natural change. In this sense, the divine creative command is the continuing logos of creation.

Wisdom and design: Nature as a Pointer to the Divine Craftsman

An interpretation of nature as the product of "intelligent design" was as much pagan as monotheistic. It originated with pagan philosophers such as Herakleitos of Ephesos, Anaxagoras of Klazomenai, Plato, Galen and Cicero. For these pagan scientists, nature was the divine craftsman, designing itself. Yet the metaphor of nature as a work of craftmanship was easily appropriated into pastoral admonitions to consider the wisdom of the Creator by Basil and other early Hebrew, Christian and Islamic theists.

Note on "intelligent design": the phrase "Intelligent Design" has been adopted by modern critics of evolution, so I need to point out that that is NOT the sense used here. Note that we're talking now about "intelligent design" with all lowercase letters. In contrast, the modern form, "Intelligent Design" with a capital I and a capital D, discerns the Creator's hand in miracles more than in natural laws, contrary to the previous paragraph on natural law. So discussions of purpose and design in nature have a long history, both before and after 19th century theories of evolution and ongoing debates over "Intelligent Design" today. But there are some major differences between the "Intelligent Design" of anti-evolutionists today (capital I and capital D) and the intelligent design (lowercase i and lowercase d) of many historical writers like those we are encountering in this course. For example, both theist and pagan advocates of today's controversial version of Intelligent Design restrict purpose in nature to only those things that cannot be explained by natural laws (which they call "scientifically detectable" design). Those pagan and theistic writers we will consider in this course who wrote of nature as a pointer to the wisdom and design of the Creator, however, made no such opposition between the results of natural law and of the divine purpose. Theists pointed to both natural objects and natural causes and natural laws as equally the result of the divine wisdom; the same is true of Roman Stoics such as Cicero and Galen. Now back to Basil...

Basil drew upon the biological studies of Aristotle, Theophrastos and others to portray the design of the natural world as a manifestation of divine wisdom. Here are a few examples:

"Not only among the large animals is it possible to see his inscrutable wisdom, but even among the smallest it is possible to find no less marvels.... I do not admire the huge elephant more than the mouse, which is formidable to the elephant, or than the very fine sting of the scorpion, which the Craftsman hollowed out like a tube so that through it the poison is injected into those stung." Basil Hexameron, Homily 9, pp. 144-146.

As with Aristotle and Pliny, design is evident in the small things of nature equally as in the large:

"One grass, even one blade of grass is sufficient to occupy all your intelligence completely in the consideration of the art which produced it." Homily 5, p. 71.

Contingency of Creation

Natural law and intelligent design were ideas that theists shared with the pagans and especially Stoic scientists of the day. But the most significant novelty in the conception of nature that was introduced by monotheism in the Roman period was the rejection of the dichotomy between chance and necessity (see table below).

Chance Necessity
That which rarely occurs. That which always or regularly occurs, the order of nature.
Irrational Rational

For pagans such as Aristotle, changes in nature were either by necessity (if they are natural and regular), or by chance (if they are not predictable). There were no other options. According to Aristotle, things that arise by chance (that is, that are not predictable or regular) are not intelligible by their very nature; they are irrational. Although the Stoics later rejected the existence of chance, even for the Stoics everything was necessary, and so they were still caught within the conceptual framework of necessity and chance.

In contrast, theists like Basil and Augustine did not have to choose between necessity and chance, for in a theistic interpretation all things result from the divine will, whether regular or irregular. For theists, nothing in nature occurs by necessity, and nothing occurs by chance either (in the sense of being irrational). Everything is potentially intelligible if seen in relation to the divine will. For a theist, the universe and everything it contains is contingent rather than either necessary or by chance. In other words, it remains intelligible, although it might have been otherwise; this is the definition of contingency in a nutshell. Even unusual things and rare events may become intelligible, if nature is contingent.

"Everything in existence is the work of Providence, and nothing is bereft of the care owed to it." Homily 9, p. 144.

In other words, if we define the word contingent as "that which might have been otherwise," then early theists like Basil substituted a conception of nature as contingent on the divine will for a pagan view of nature as the product of chance and necessity. Even natural laws are a "contingent order" rather than a necessity.

Contingent order
Chance Natural Law
That which rarely occurs. That which always or regularly occurs, the order of nature.
Intelligible Intelligible

We have seen before that answers to the question "How is nature known?" often depend upon the answers given to the prior question "What is nature?" It is the same with the theistic view. The theistic view of nature as contingent would hold immense implications for ideas of how nature is known, for at least three reasons:

Let's expand briefly on each of these consequences of the idea that nature is contingent rather than necessary, although we will see these implications worked out more thoroughly in our study of late medieval and Newtonian science.

1. Contingency of Natural Laws

First, the theistic insistence of the contingent dependence of the natural order upon the absolute power of God carried a corollary insistence upon the contingency of natural laws. Basil insisted that natural laws, e.g., of water and earth, exist in absolute dependence upon God's power and creative word (Homily 4, p. 57 etc.).

"The voice of God makes nature, and the command given at that time to creation provided the future course of action for the creatures.... The element water was ordered to flow, and it never grows weary when urged on unceasingly by this command." Homily 4, p. 57.

Commentary on Genesis 1:11, "Let the earth bring forth vegetation": "For, the voice which was then heard and that first command became, as it were, a law of nature [nomos physeos] and remained in the earth, giving it the power to produce and bear fruit for all succeeding time." Homily 5, p. 67.

In other words, the Creator might have created an ordered universe that followed different natural laws than the ones we know. There was no necessity for the deity to create the universe in the way he actually chose to do so. We can count on natural laws in this universe, but they were not inevitable. Physical law is a contingent form of order, not necessary but freely chosen by the Creator. Therefore natural laws are intelligible but not necessary. The natural order arises neither by chance nor by necessity, but contingently.

Why does this matter? The simple consequence of the contingency of creation is that logical necessity could no longer be used to demonstrate how the universe must be ordered.

As an example, consider the element of water, noted above, which received its "natural tendency to flow downward" as a law of a nature during the creation. In other words, there is nothing intrinsic in water itself that made it necessary to always flow downward, and it would be possible for the world to have been ordered in a different manner. Basil went on to argue that it is possible that some water in the universe might be located beyond the sublunar regions, above the heavens, contrary to Aristotle:

"Let them cease making trouble for themselves or for us, alleging that water cannot be kept in the upper regions." Homily 3, p. 42.

This was quite an anti-Aristotelian conclusion! Another similar result of the denial of necessity was Basil's insistence, contrary to Aristotle, that there might be many worlds or universes (described below).

2. Empirical Methods, Importance of sensory experience

If nature is contingent then it must be known empirically.

This implication contrasts with the way the question "How is nature known?" was answered when nature was considered as the result of necessity and/or chance. Remember the argument of Parmenides, that reason alone, apart from sense experience, is the way to apprehend nature, which is necessary truth? Similarly, even Aristotle insisted that the only objects of knowledge must be necessary truths. Although Aristotle gave primacy to sense experience as the stimulus for reasoning about natural causes, he argued that only those things in nature which are necessary may be known. The common theme is that if nature is necessary, and could not be other than it is, then logical necessity must be the preferred way to understand nature.

In contrast, if nature is contingent, and might have been created other than it is, then necessary logical arguments will be insufficient, and will need to be supplemented with sense experience, since the universe might have been created in an unexpected way. If creation is contingent, then sense experience will be necessary to understand it, in addition to reason. Basil affirmed the value of observation of nature by both himself and others:

"I have seen these wonders myself and I have admired the wisdom of God in all things." Homily 7, p. 113.

"In what bird does nature not show some marvel peculiar to it?" Homily 8, p. 130.

Another example is Basil's description of a top, described below.

3. Variety of Creatures... Choice or Necessity?

Finally, theists often drew a third implication of the contingency of nature, namely, that the will of a personal Creator, or even his love, explains the multitudinous variety of things. Why should the universe be filled with so many different kinds of things? The theist would reason that, in contrast to a single simple outcome which might arise by blind necessity, the Creator's freedom, as in an improvisation, becomes manifest in the remarkable variety and diversity of creation:

"The words of the command were few..., yet the variety of meaning in the command is as great as the various species and families of fishes. Homily 7, p. 106.

"The words of Scripture, if simply read, are a few short syllables: 'Let the waters bring forth winged creatures that fly above the earth under the firmament of the heavens'; but, when the meaning in the words is explained, then the great marvel of the wisdom of the Creator appears. How many varieties of winged creatures He has provided for! How different He has made them from each other in species! With what distinct properties He has marked each kind! The day is failing me while I relate to you the wonders in the air." Homily 8, p. 132.

In a later week, we will see that this argument for interpreting abundant variety as a sign of the contingency of nature was presented forcefully by Newtonians such as Samuel Clarke in their defense of Newton against 17th-century forms of necessitarianism.

Example 1, Contingency of Natural Laws: Many Worlds

Basil challenged the necessitarianism of Aristotelian cosmology by arguing that, due to the transcendent power of God, God could have produced many worlds ("world" = universe). Moreover, each one of the universes might have different characteristics. In other words, Basil denied any element of necessity in the natural order, affirming the contingency of creation. In the following quotation, Basil refuted the argument of Aristotle and others that there is necessarily only one heaven, or one set of spheres, instead of possibly many universes:

"When those who employ more weighty proofs will ... prove by the laws of geometry that nature does not support the fact that another heaven besides the one has been made, then we shall only laugh the more at their geometrical and artificial nonsense. For, although they see bubbles, not only one but many, produced by the same cause, they yet doubt as to whether the creative power is capable of bringing a greater number of heavens into existence. Whenever we look upon the transcending power of God, we consider that the strength and greatness of the heavens differ not at all from that of the curved spray which spurts up in the fountains. And so, their explanation of the impossibility is laughable." Basil Hexameron, Homily 3, p. 40; cf. p. 6.

Basil's remarks about "bubble universes" resonate in astrophysics today, just as they did much later in the condemnations of 1277 where Aristotle's position that God could not have made a plurality of worlds was condemned by a medieval Bishop of Paris (as we shall see in a later week). To be clear, Basil did not argue that multiple worlds do exist, but he insisted they are possible and denied Aristotle's contention that there is necessarily only one world. For Basil, the most important question was not how many worlds there are, but whether nature is contingent rather than necessary.

Example 2, Empirical Methods: John Philoponos and anti-Aristotelian physics

The most famous example of Basil's influence on empirical methods in physics is the passage on the top, quoted above. Here, again, is the relevent sentence:

"... just as tops, from the first impulse given to them, produce successive whirls when they are spun, so also the order of nature, having received its beginning from that first command, continues to all time thereafter, until it shall reach the common consummation of all things." Basil Hexameron, Homily 5, p. 82.

Aristotle's theory of motion, although based on common sense experience, could not explain the continuing motion of a spinning top. For Aristotle, an object in motion continues to move only so long as something continues to move it. In other words, just as a cart stops when a horse stops pulling it, so when any mover stops pushing, the thing that is moved ceases to move.

One problem with Aristotle's theory was the motion of projectiles. For example, what keeps an arrow moving after it has left the bow? The bow starts the arrow moving initially, but what keeps the arrow moving along when it is in the air? Aristotle's provisional answer was antiperistasis, that air pushed out of the way by the tip of the arrow moves around to the back to push the arrow in a cyclic loop. This answer faced several problems even in explaining projectile motion, but the theory seemed to break down completely when applied to the top. On Aristotle's view, how could air move around behind the top to keep the top spinning?

Basil's answer was that the top demonstrates a continuing efficacy of the original impulse of movement, analogous to the original impulse given to the world by the Creator at its creation. For Basil, the spinning top is a perfectly natural motion according to the laws governing the order of nature.

In the 6th century in Athens, the anti-Aristotelian physicist John Philoponos, influenced by Basil's Hexameron, used the example of the top to formulate a theory of an "impressed incorporeal motive force." This force maintains the motion of a spinning top imparted by an initial impulse, and in a similar manner, of moving projectiles. The theory of Philoponos, carried on in the Syriac hexameral tradition and the works of Islamic physicsts, was revived again in the 14th-century impetus theory of Jean Buridan and Nicole Oresme, which we will examine in a later week as the foundation for 17th-century theories of inertia.

Philoponos also attacked Aristotle's theory of motion in the case of free fall. For Aristotle, heavy things are made of the elements of earth and water, and naturally strive toward the center of the universe. The heavier any thing is, the faster it should fall. Aristotle did not formulate this principle into a mathematical proportion comparing weight and speed of fall, but merely noted that heavy things do in fact hit the ground before lighter things, if dropped from a great height at the same time. (In terms of modern physics, this result occurs because air resistance slows the lighter things more than the heavier things.)

Philoponos cast Aristotelian physics into mathematical form, defining Aristotle's theory as proposing that the weight of an object is proportional to its speed of fall. Such a proportion could be empirically tested. Philoponos dropped objects of varying weights from the top of a tall tower, recording the differences in time for them to hit the ground. As any modern student of physics knows, the time of fall is not proportional to the weight of an object. Although this experiment is often falsely attributed to Galileo at the leaning tower of Pisa, in the 6th century, Philoponos used this experimental evidence to refute Aristotle's theory of natural motion and to construct an important anti-Aristotelian tradition in the physics of motion.

These examples illustrate how if theists like Basil and Philoponos viewed nature as contingent, then empirical methods would come to play a more prominent role in how nature would be known.

Example 3: From eternal cycles to a linear history

Is nature constant, cyclical or historical? There is another interesting implication of the contingency of nature, and that is the significance of a history of nature. A contingent nature may have an interesting linear history, instead of being constant or cyclical. Pagan views of nature envisioned either a constant, changeless substance (like Parmenides) or explained its changes as cyclical and therefore eternal. In an example of the latter, Basil described the necessitarian cycle of cosmic conflagrations adhered to by Stoics such as Seneca and Cicero:

"They say that the universe is being utterly consumed and again comes to life from the seminal principles which remain in what has been completely burnt up. From this assertion, they introduce infinite destructions and regenerations of the world" (Homily 3, p. 51).

Basil renounced pagan ideas of endless cycles in favor of a linear view of history. But Basil did affirm the Stoic conception of a future conflagration of the universe, not as the end of one cycle and the beginning of another in an eternal return, but as the consummation and climax of Earth history:

"The Ruler of the universe [Pantokrater] ordained from the beginning such a nature for moisture that, although gradually consumed by the power of fire, it would hold out even to the limits prescribed for the existence of the world. He who disposes all things by weight and measure (for, 'easily numbered by Him are even the drops of rain,' according to Job) knew how long a time He had appointed to the world for its continuance, and how much [water] had to be set aside from the first for consumption by the fire. This is the explanation for the superabundance of water in the creation." Basil, Hexameron, Homily 3, p. 45.


We'll give Basil a chance to offer some famous last words:

"In truth, to know oneself seems to be the hardest of all things." Homily 9, p. 147.

And for the last word on Basil's historical significance, we'll conclude with this quote from Thomas Torrance, one of the most influential writers on science and religion in the 20th century:

"Essential to [Basil's] cosmological outlook lies the Christian concept of the radical contingence of the universe and its rational order. And central to all that is the conception, so impossible for the ancient Greeks, of the contingent nature of the human mind created by God out of nothing but given a unique relation to his own transcendent Mind through grace. The incorporation of those ideas in Basil's Hexameron played a very important role, not only in challenging the intellectual foundations of the classical outlook upon the world of visible and invisible reality, but in helping to transform the Greek mind in a way that has left its mark upon the very basis of western culture." Thomas F. Torrance, The Christian Frame of Mind, p. 5.


All quotations from Basil's Hexameron are from Saint Basil: Exegetic Homilies, trans. Agnes Clare Way, The Fathers of the Church series (Washington, D.C.: Catholic University of America, 1963).

Christopher B. Kaiser, Creational Theology and the History of Physical Science: The Creationist Tradition from Basil to Bohr, vol. 78 of Studies in the History of Christian Thought, ed. Heiko A. Oberman (Leiden: Brill, 1997). The first chapter is an excellent starting point for exploring the significance of Basil for the history of science.

D.S. Wallace-Hadrill, The Greek Patristic View of Nature (New York: Manchester University Press, 1968).

John F. Callahan, "Greek Philosophy and the Cappadocian Cosmology," Dumbarton Oaks Papers. 12 (1958): 29-57.

Thomas F. Torrance, The Christian Frame of Mind: Reason, Order and Openness in Theology and Natural Science (Colorado Springs: Helmers and Howard, 1989).

Francis Oakley, Omnipotence, Covenant and Order (Cornell University Press, 1984). An influential scholarly survey of the implications of the doctrine of divine omnipotence for the history of ideas.


"The thing itself [the universe] did not provide the cause of its own existence." Basil Hexameron, Homily 1, p. 12.

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