| Lydia Jaeger FAITH Magazine January-February 2009 |
Dr. Lydia Jaeger suggests that a latent Greek-inspired dualism prevents Thomas Aquinas' hylomorphism from cohering with modern insights into the mathematical intelligibility of the phenomenon of change. She is Director of Studies at the Institut Biblique de Nogent-sur-Marne on the outskirts of Paris, a College for Christian leaders in the Evangelical tradition. This is a developed extract of a paper given at the joint conference of the American Scientific Affiliation and Christians in Science, in Edinburgh, on 3rd August 2007.
1. The Greek Concept of Matter and Creation Ex Nihilo
It has become customary to consider that modern science was born in a revolution: science, as it has been practised since the seventeenth century, is not the continuous development and enhancement of ancient and medieval science, but operates within a significantly different conceptual framework and methodology. A wide variety of changes occurred during the so-called scientific revolution. This paper concentrates on the concept of matter and the implications its mutation (or perhaps one might even say, abandonment) has had on scientific methodology. The chosen focus does not, of course, imply the idea that the change in the concept of matter was the most important, let alone the only factor in the scientific revolution. It is nevertheless interesting to single out this particular concept, in order to grasp one significant aspect of the revolutionary development which led to modern science.
The Ionian physicists first employed the concept of matter in the 6th century B.C., in order to explain physical changes by invoking one or more kinds of universal underlying "stuff". The concept was then used by Plato, Aristotle and subsequent philosophers in a variety of contexts, with at times rather contrasting meanings. Ernan McMullin lists eight different roles matter played in ancient Greek philosophy: the "substratum of change", the "principle of individuation and multiplicity", space as a receptacle for form, "the locus of potentiality", "the source of defect", the contrasting principle "over against life, mind and Divinity", "a factor in explanation" (the so called material cause) and "the ultimate subject of predication".[1] A thorough examination of the development of the concept of matter would need to take into account these differing meanings and distinguish between varying uses of the concept depending on historical period and individual authors.[2] In order to keep the length of this article inside reasonable limits, it is necessary to focus our attention on particular salient aspects of the change that occurred. I will therefore mainly concentrate on the (predominantly Platonic) understanding of matter as the source of defect and examine how it relates to the notion of creation ex nihilo and to the modern scientific paradigm.
When the Church fathers came into contact with Greek philosophy, they could not assimilate the Greek concept of matter without significant change. The doctrine of creation ex nihilo led them to confess God as the Creator
and Sustainer of everything, including matter. Thus matter came under the direct responsibility and reign of the omnipotent, benevolent and wise Creator God. Therefore it could no longer be seen as the source of defect (or even less of evil, as the Gnostics thought). Nor could it be eternal, as Aristotle had thought that unformed matter, as the substratum underlying all change, was itself without any change. In particular, Christian theologians could not represent the creation of the world as the work of a demiurge impressing form on pre-existing matter. Instead, the theologians of the ancient Church had to affirm their belief in the creation of matter also. Augustine wrestles with exactly this question, when commenting in his Confessions the opening verses of the Bible: "Before thou shapedst and diversifiedst this unshapen matter [informem materiam], there was nothing, neither colour, nor figure, nor body, nor spirit."[3] But according to Greek thought, formed matter was preceded by unformed matter: "And yet was there not altogether an absolute nothing; for there was a certain unshapedness, without any form in it."[4] But in order to be faithful to the conviction that the origin of all reality lies in God, Augustine considers that matter itself is created and finds biblical support for this doctrine in the second verse of the first chapter of Genesis: he interprets the tohu-bohu (Gen. 1:2) as referring to "the unshapedness of the first matter [informitatem matehae] which thou createdst without form (of which thou wert to make this goodly world)".[5] In particular, our understanding of creation should not be based on the analogy with a human craftsman in as much as he always works with what already exists. On the contrary, all things come from God: "Tis thou that madest the artificer his body, thou gavest a soul to direct his limbs; thou madest the stuff [materiam] of which he makes anything; thou madest that apprehension whereby he may take his art."[6] God himself does not depend on any pre-existent thing in his work of creation: "Nor didst thou hold anything in thy hand whereof to make this heaven and earth: for how couldst thou come by that which thyself hadst not made, to make anything? For what hath any being, but only because thou art?"[7].
2. The Creation of Matter and the Possibility of Empirical Science
Postulating the creation of matter leads to a very different perspective on the contingency of our world, compared to the conception of a world formed by a demiurge. In the Judaeo-Christian view, contingency is not the result of an imperfect formation process, but stems from the free will of the omnipotent Creator. The work of a demiurge is only contingent insofar as he does not succeed in implementing the telos that he had in mind. Therefore, if there is any deviation from the rational essence of things, it results from imperfection; it is caused by the limitations of the demiurge. As he works with pre-existing matter, he is not omnipotent, but has to face its resistance. Thus the world produced by the demiurge can in no way be the subject of empirical science. In as far as the work of the demiurge is successful, it is completely transparent to contemplation for the essence of things allows for an exhaustive rational understanding, as they arise from a (finite) intelligence which has informed matter. As a result, no experiments are necessary to understand nature. In as far as the work of the demiurge is imperfect, it does not allow science -either empirical, or rational - because the deviation from the original telos follows no rules, but arises from a principle of irrationality.[8]
Creation as a voluntary act of the omnipotent Intelligence can, on the other hand, be used to undergird the empirical method which governs the new scientific approach, from the 17th century onwards. The notion of creation combines rational work with free act, in such a way that contingency is no longer the result of imperfection, but expresses the freedom of the almighty Creator:
The changed value of the notion of contingency consists of the fact that the contingent no longer has its basis in the indeterminacy of matter, but in the freedom of the divine will, as the creative foundation of the world and all its parts.[9]Thus, creationism believes that the contingent - as contingent - is understandable, which helps to explain the empirical approach of modern science. On the one hand, reality is accessible to scientific description, since it has its origin in God, who is both almighty and rational. On the other hand, rational conjecture is not enough to grasp the natural order, since it is the result of a free act, and is therefore not necessary: scientists must, through their experiments, learn which laws God has established in the created world.
3. Science and History
Not only does the changed perspective that the notion of creation brings to contingency encourage the empirical approach, but the world with its real historical development becomes the subject of scientific enquiry. For the coming into being of the material world is not explained by the meeting of form and matter (where only the former is subject to rational laws), but has its foundation in the historic action of the Creator, who is supremely rational. It is very instructive to compare this view to that demonstrated in Plato's Timaeus, a particularly good
example of how Greek philosophy struggled to incorporate history. The "likely account"[10] which the Timaeus provides about the origin of the world affirms from the outset the opposition between rationality and history:
What is that which is Existent always and has no Becoming? And what is that which is Becoming always and never is Existent? Now the one of these is apprehensible by thought with the aid of reasoning, since it is ever uniformly existent; whereas the other is an object of opinion with the aid of unreasoning sensation, since it becomes and perishes and is never really existent.[11]
For Plato, that which is perceptible and changing is not the subject of knowledge. Since the intellect can only grasp that which is eternal, our world and its historic coming into being escapes reason. But the idea of creation implies a significantly different perspective on history, as the natural order is by its very essence historical, that is, the result of a temporal action, which nevertheless is not capricious, but the orderly work of the God of all wisdom. Therefore, reason is able to explore change; historical evolution is not opposed to rational inquiry.[12]
The rationality of becoming, in the light of creation, takes on particular significance from the moment the natural sciences decisively opened up to the historical dimension. This happened most spectacularly in biology in the 19th and in cosmology in the 20th century. Although it might be difficult to prove historically that the idea of creation played a positive role in this change of the scientific outlook, it is still noteworthy that on the conceptual level, there is no contradiction between creation and a more historical approach in natural sciences. Quite to the contrary, viewing the world as created implies that the natural order is subject to change in history. Thus the dichotomy between the "hard" sciences and history breaks down, and it is to be expected that the exact sciences incorporate a historical dimension. Although a number of Christians rejected Darwin's theory of evolution, it should not be inferred from that that the idea of creation implies fixity. Not only have other Christians, among the most conservative, accepted the new biological paradigm without any problem,[13] but it is even likely that the idea of contingency of the natural order that creation implies eased the acceptance of an evolving cosmos in astronomy. Recall that Georges LemaTtre, who first introduced the Big Bang idea in 1927, was a Catholic priest, whereas Einstein's spinosism was probably a factor in his initial reluctance to the idea of cosmic evolution.[14] Whatever attitudes that Christians have adopted faced with the historicising turning point of the natural sciences in the 19th and 20th centuries, there is no reason, in the perspective of creation, to represent scientific and historical descriptions as being in opposition. On the contrary, since natural laws are not eternal, the natural sciences cannot but be open to history.
4. Exact Science in a Material World
The statement that creation is ex nihilo rules out any trace of polytheism: no independent principle or being can remain, since God is the Creator of all facets of reality. As such he has perfect mastery over the world; nothing can escape his control. If matter also is created, it is included under the wise governance of the Creator and thus cannot constitute an irrational principle. While for the Greeks (and in particular Plato), matter was only understandable inasmuch as it was "in-formed", matter created by an orderly and wise God does not in principle pose any obstacle to rational understanding. The new philosophy of nature which took shape in the 17th century was based on the conviction that the perceptible, the material, in itself, is the subject of rational knowledge. On this point it is perfectly in agreement with the idea of creation: since all that exists is the work of an infinitely wise God, nothing is fundamentally irrational and unintelligible. In such a vision, "reality is substantial nourishment for the intellect. Nothing is inert, insignificant, alien or unable to be assimilated. No 'matter' in the sense of 'stuff resistant to the intellect', utter waste for the mind."[15]
In fact, at the birth of modern science, the debate over the status of matter was present. Galileo plays out several times, in his imaginary dialogues, the disagreement on the supposed imperfection of the material world. In the Dialogue on the Great World Systems, Salviati, advocate for Galileo, insists that mathematical description applies to material objects themselves. He thereby opposes the views of Simplicio, according to whom "it is the imperfection of matter that makes the matters taken in concrete to disagree with those taken in abstract."[16] To the contrary, says Salviati, "what happens in the concrete does in like manner hold true in the abstract", so that mathematical calculations apply perfectly to our material world." If a round object touches a plane surface at more than one point, this is not because it is material, but because it is not truly a sphere.[17] In the Discourses concerning Two New Sciences, the learned Italian loosens the traditional link between the material realisation of forms and the approximation inherent in any scientific description of the world: the approximation is an integral part of the theoretical models used in science, independently of the material nature of the objects being studied. Thus, the description of free-fall ignores the fact that the earth's gravitational field lines are not exactly parallel to each other due to the round shape of the earth.[18]
At first sight, the difference might seem trivial: in explaining why a round object touches a plane surface at more than one point, one side maintains that the material object is an
imperfect realisation of an ideal sphere, the other that it is not an exact sphere. But in fact, the two perspectives are profoundly divergent. This becomes clear in the different ways they treat the deviation from the spherical form: for Simplicio, the material imperfection is the end of all possible explanation. Salviati, however, immediately seeks an exact mathematical description of how the object deviates from the ideal form. If it is not exactly a sphere, it is exactly something else! From whence comes the revolutionary assertion that the book of nature is written in mathematical characters:
The book of philosophy [...] stands perpetually open before our eyes, though since it is written in characters different from those of our alphabet it cannot be read by everyone; and the characters of such a book are triangles, squares, circles, spheres, cones, pyramids, and other mathematical figures, most apt for such a reading.[19]Refusing to link material realisation and imperfection led to an original attitude to experimental data: the conviction that nature allows an exact mathematical description generated an expectation of finding a more comprehensive and universal order than that which appears at first Platonic-inspired glance. To use Kantian terms, trust in the mathematical structure of the world acted as a regulative principle for Galileo: it made him carefully monitor the setting-up of his experiments, in his quest to draw out the natural order which can evade the inattentive and unsophisticated eye of the ordinary observer.
5. St. Thomas Aquinas' Synthesis
While creation ex nihilo would in the end call into question the Greek antithesis of matter and form, it is undeniable that Christian theology was slow to exploit the revolutionary leverage which this central doctrine contained. In order to illustrate this point, it is very instructive to study the ideas of Thomas Aquinas, who tried to synthesise the Aristotelian and Christian perspectives. In its contact with the Arab world, the West had rediscovered the works of Aristotle, such that at the start of the 13th century, young intellectuals leant on a certain reading of the Stagirite to critique traditional thinking, which up to that point was heavily dominated by Platonism. Thomas therefore strove to present Christian doctrine in a rational way, profiting from the conceptual tools that Aristotelian philosophy had made available. His Summa contra Gentiles targets precisely Muslim commentators of Aristotle, and the questioning of Christian theology that their reading might produce.
In line with ecclesiastical tradition, Thomas asserted that the world in its entirety owes its being to God, for "everything besides Himself is from Him."[20] He must therefore distance himself from the Stagirite, to reject the eternity of matter and assert creation ex nihilo: "God brought things into being out of no pre-existent thing as matter."[21] At the same time, he appropriates the dualism between form and matter, which underlies Aristotelian philosophy. But to stay faithful to received doctrine, he cannot identify God with any of these two structural principles. On one hand, he asserts that "God is not matter" which follows from creation ex nihilo; for "God created all things not out His own substance, but out of nothing."[22] Thus there cannot be continuity between matter constitutive of the created world and divine essence. On the other hand, he rejects "the error of some who have asserted that God is nothing else than the formal being of everything."[23]
A shift occurs, however, when Thomas follows Aristotle in his definition of the divine as that which "is wholly actual, and nowise potential"[24] and when he identifies matter with passive potentiality: "For matter, such as it is, is in potentiality."[25] Thus matter threatens to become a principle alien to God. Their mutual relationship is that of "opposite differences [...]: the one being pure act and the other pure potentiality, they have nothing in common."[26] The creation of matter therefore poses a problem, for how could God create that which is opposed to him? Thomas shows his awareness of the difficulty when he treats, in Summa theologica, the objection which follows from it: "Action and passion are opposite members of a division. But as the first active principle is God, so the first passive principle is matter. Therefore God and primary matter are two principles divided against each other, neither of which is from the other."[27]
Greek philosophy had resolved the problem by positing the eternity of matter - an outcome which Thomas cannot take on board without breaking with received doctrine. He must assert the creation of matter, even if this makes little sense in the conceptual framework which he inherits from the Stagirite.[28] Thomas therefore seeks to evade the objection by assuming that potentiality derives from actuality: "Passion is an effect of action. Hence it is reasonable that the first passive principle should be the effect of the first active principle, since every imperfect thing is caused by one perfect. For the first principle must be most perfect, as Aristotle says."[29] But does it make sense, in Thomas's system, to postulate that a cause has an effect which is fundamentally dissimilar, even opposed, to it? Hence it seems difficult to accept that pure action should give rise to passion, the perfect to the imperfect: the relationship between God and matter remains enigmatic, as long as one adopts such antithetical concepts in order to express the difference between the Creator and the creature. Thomas' answer to the objection counts for little more than a principled petition; it does hardly anything else but repeat
the conviction that matter comes from God, without really shedding any light on the relationship between these two opposites. We move no doubt towards a solution when Thomas states that matter is not created as such, but always attached to a form.[30] But even this assertion doesn't succeed in providing a satisfactory answer to the objection. It is true from a Christian standpoint that "it is necessary that even what is potential in it [every creature] should be created";[31] but how could pure action confer existence on that which is opposed to it, in its very essence?
In asserting that God alone is pure action, Thomas seeks to express a fundamental conviction in the idea of creation: it is impossible to include, in the same category of being, the Creator and his creatures. On this note, it is significant that the term analogia entis is not used by Thomas: divine transcendence does not allow any general concept of being into which can be subsumed God and the world.[32] But his thinking is still tied to the antithesis of matter and form, of potentiality and act. There is therefore the risk of understanding the being of created things as dependent on two heterogeneous principles: pure act and matter, where the latter constitutes a principle opposed to God. To assimilate it with potentiality, and therefore non-being, doesn't avoid conferring it with its own metaphysical status, which threatens the monotheistic character of Thomas' proposition.
The latent dualism of Thomas Aquinas' scheme has noteworthy repercussions on his understanding of the scientific method. Without attempting to cover the entirety of his ideas on the subject, let us observe two implications which are directly related to his treatment of matter. Firstly, we find in his ideas the Greek belief that matter in itself is not intelligible:
Forms are not actually intelligible except according as they are separated from matter and from its conditions; nor are they made actually intelligible except by the power of a substance understanding them, according as they are received into, and are affected by, that substance.He rejects in particular the idea that "it is only corporeal matter that impedes intelligibility, and not any matter whatsoever."[34] Matter in its very essence, evades reasoning.
Whence it is necessary that there be in any intelligent substance a complete freedom from matter, such that the substance does not have matter as a part of, such too that the substance is not a form impressed on matter, as is the case with material forms.[33]
Secondly, he accords to matter the role of resisting form. Movement always requires a small amount of time, owing to "a defect of the matter, that is not suitably disposed from the beginning for the reception of the form."[35] Similarly, matter gives the explanation for the failures that an agent endures in his attempts to act: Those things which are referable to matter as their first cause, are beside the intention of the agent; for instance monsters and other mischances [peccata] of nature. But the form results from the intention of the agent. This is proved thus. The agent produces its like according to its form, and if sometimes this fails, it is from chance on account of a defect in the matter.[36]
6. Conclusion
To accord to matter the power to oppose the ordaining power of the Creator is foreign to biblical monotheism. Creation ex nihilo goes hand in hand with God's perfect mastery of all elements of reality. Here Thomas pays the price for the synthesis he tries to work with Aristotelian
philosophy. He does not draw all the conclusions offered by the doctrine of creation ex nihilo, which he nevertheless affirms. But taking fully into account the implications of this doctrine is a key element in elaborating the idea of the universality of the reign of the laws of nature which makes it possible to reach a modern scientific understanding of law. As John Milton states it:
The barrier which must inevitably prevent any systematic attempt to think of natural phenomena as governed by [universal] laws is the absence of a belief in creation ex nihilo. If the world does not owe its whole existence to God, then no divine law can provide the fundamental explication of the nature of things.[37]
[1]Ernan MCMULLIN, "Introduction: the concept of matter in transition", in The concept of matter in modern philosophy, ed. E. MCMULLIN, Notre Dame (IN), Univ. of ND. Press,
1978, p. 5-12.
[2]See for example Ernan MCMULLIN (ed.), The concept of matter in Greek and medieval philosophy, Notre Dame (IN), Univ. of N.D. Press, 1965, and The concept of matter in modern philosophy, 1978.
[3]St. Augustine's Confessions XII-3, «The Loeb Classical Library», transl. William WATTS, 1631, Cambridge (MA), Harvard Univ. Press, 1946, vol. I, p. 293.
[4]Ibid.
[5]'Ibid. XII-4, p. 293. For the controversial exegesis of this verse, cf Victor P. HAMILTON, The book of Genesis: chapters 1-17, New International Commentary of the Old Testament, Grand Rapids (MI), Eerdmans, 1990, p. 108-117.
[6]St. Augustine's Confessions XI-5, p. 219.
[7]Ibid. p. 220.
[8]Michael FOSTER, "Christian theology and modern science of nature (II)", MindXIN, 1936, p. 4-7. Foster quotes two passages from the writings of Francis Bacon, which show how the idea of an all-powerful God allowed a transition from a concept of imperfectly realised forms, to one of forms which are open to scientific description and
effectively given in nature (ibid. p. 7, n. 1).
[9]Wolfhart PANNENBERG, "Die Kontingenz der geschopflichen Wirklichkeit", Theologische Literatur^eitung CXIX, 1994, p. 1052. This different perspective on contingency
constitutes, for Pannenberg, one of the major contributions that Christian theology has made to the philosophy of science; e.g. "The doctrine of creation and modern science",
1989, Toward a theology of nature: essays on science and faith, ed. Ted PETERS, Louisville (KY), Westminster/John Knox Press, 1993, p. 36f, and "Contingency and natural law",
1970, ibid. p. 115f For the role that contingency plays in the created order in Newtonian empiricism, cf. L.JAEGER, "The idea of law in science and religion", Science and Christian Belief XX, 2008, p. 133-146.
[10]PLATO, Timaeus 29d, Plato in twelve volumes, "The Loeb Classical Library", vol. IX, trad. R.B. BURY, Cambridge (MA), Harvard Univ. Press, 1929, p. 53.
[11]27d-28a, p. 49; cf. ibid. 51d-52a, p. 121f
[12]W. PANNENBERG, "Theological questions to scientists", Toward a theology of nature, p. 21, and "Contingency and natural law", 1970, ibid. p. 78, 90; Ted PETERS, "Cosmos
as creation", in Cosmos as creation: theology and science in consonance, ed. T PETERS, Nashville (TN), Abingdon Press, 1989, p. 101.
[13]As for ex. Benjamin B. WARFIELD (1851-1921), dogmatician at Princeton Theological Seminary, known for his defence of biblical inerrancy (Evolution, science, and Scripture:selected writings, ed. MA. NOLL, D.N. LIVINGSTONE, Grand Rapids (MI), Baker, 2000, passim). Cf. David N. LIVINGSTONE, Darwin's forgotten defenders: the encounter between Evangelical theology and evolutionary thought, 1987, passim, and «Situating Evangelical responses to evolution)), in Evangelicals and science in historical perspective, ed. D.N.
LIVINGSTONE, DG. HART, MA. NOLL, Edinburgh, Scottish Academic Press, 1999, p. 193-219.
[14]Many 19th-century philosophers advocated an eternal universe, conceived of as an infinite series of cycles (Stanley L. JAKI, Science and creation: from eternal cycles to an oscillating
universe, Edinburgh, Scottish Academic Press, 1974, p. 309 s, 311 3, 319-322, names, in particular, Schelling, Engels and Nietzsche). Jaki believed that many scientists' resistance
to general relativity's finite universe was due to the attractiveness of the Greek idea of an eternal universe (ibid. ch. 14).
[15]Claude TRESMONTANT, Etudes de metaphysique biblique, Paris, Gabalda, 1955, p. 220 (translated by Jonathan Vaughan). "
[16]Dialogue on the Great World Systems, 1632, Second Day, transl. T SALUSBURY, 1661, rev. G. DE SANTILLANA, Chicago (IL), Univ. of Chicago Press, 1953, p. 220 (Le opere
di Galileo Galilei, 1968, vol. VII, p. 332).For the imperfect realisation of mathematical forms in material objects, cf. also PLATO, Timaeus 50b, 53b, 56c, p. 117,127, 137.
[17]Dialogue on the Great World Systems, Second Day, p. 222 (Opere, vol. VII, p. 333). Ernan McMullin pointed out to me that Galileo was not entirely consistent on this issue.
At one point he wrote that "conclusions demonstrated in the abstract are altered in the concrete", but that demonstration in the abstract ought to be sufficient for the
purposes of science (Two New Sciences, 1638, Fourth Day, transl. S. DRAKE, Univ. of Wisconsin Press, 1974, p. 223 (Opere, vol. VIII, p. 274). Cf. E. MCMULLIN "The
conception of science in Galileo's work", in New perspectives on Galileo, R.E. BUTTS, J.C. PITT, Dordrecht/Boston, Reidel, 1978, p. 209-258.
[18]'Two New Sciences, 1638, Fourth Day, p. 223f (Opere, vol. VIII, p. 274 s).
[19]GALILEO, Letter to Fortunio Liceti, January 1641, in Stillmann DRAKE, Galileo at work: his scientific biography, Chicago (IL), Univ. of Chicago Press, 1978, p. 412 (italics mine).
[20]The Summa contra Gentiles, 1259-1265, II, XV, transl. by the English Dominican Fathers, London, Burns Oates & Washbourne, 1923, vol. 2, p. 18.
[21]Ibid. II, XVI, p. 21; cf. II, XIX, p. 29.
[22]Ibid. I, XVII, transl. by the English Dominican Fathers, 1924, vol. 1, p. 38.
[23]Ibid. I, XXVI, p. 62.
[24]Ibid. I, XVI, p. 37.
[25]Tbid. I, XVII, p. 38.
[26]'Ibid. I, XVII, p. 39.
[27] Summa theological^, 1267/68 (?), q. 44, art. 2, obj. 2, transl. by Fathers of the English Dominican Province, Notre Dame (IN), Christian Classics, 1981, p. 230.
[28]Cf Herman DOOYEWEERD, A new critique of theoretical thought, vol. I, Philipsburg (NJ), Presbyterian & Reformed, 1953, p. 180,182.
[29]Summa theologica la, q. 44, art. 2, rep. 2, p. 230.
[30]Ibid. rep. 3, p. 230.
[31]Hbid.
[32]Summa contra Gentiles, I, XXXIV P- 79.
[33] On Being and Essence, IV, 1,1254/55, in Joseph BOBIK, Aquinas on Being and essence: a translation and interpretation, Notre Dame (IN), Univ. of N.D Press, 1965, § 68f, p. 135f
[34]Ibid. IV, 2; BOBIK, § 70, p. 136. Cf. Summa theologica la, q. 12, art. 4, p. 52; et ibid. q. 14, art. l,p. 72.
[35]'Summa contra Gentiles II, XIX, p. 29; cf. II, XXV, p. 44: "Potentiality of being is in those things only which have matter subject to contrariety."
[36]Ibid. II, XL, p. 88 s.
[37]"The origin and development of the concept of the 'laws of nature"', Archives europeennes de sociologie~KXlI, 1981, p. 187.