Transversal's Duhem issue

Transversal's issue dedicated to Duhem has been released; it's open-access (full issue PDF):

“Dossier Pierre Duhem.” Transversal: International Journal for the Historiography of Science, no. 2 (2017). https://www.historiographyofscience.org/index.php/transversal/issue/view/6.

No 2 (2017)

Dossier Pierre Duhem

Pierre Duhem’s Philosophy and History of Science

Full Issue

View or download the full issue

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Table of Contents

From the Editors

Historiography of Science: The Link between History and Philosophy in Understanding Science Mauro L. Condé, Marlon Salomon

PDF 01

Dossiers (Issue-specific topics)

Introduction Fábio Rodrigo Leite, Jean-François Stoffel

PDF 03

Duhem’s Analysis of Newtonian Method and the Logical Priority of Physics over Metaphysics Eduardo Salles de Oliveira Barra, Ricardo Batista dos Santos

PDF 07

The French Roots of Duhem’s early Historiography and Epistemology Stefano Bordoni

PDF 20

Duhem’s Critical Analysis of Mechanicism and his Defense of a Formal Conception of Theoretical Physics José R. N. Chiappin, Cássio Costa Laranjeiras

PDF 36

Anti-Scepticism and Epistemic Humility in Pierre Duhem’s Philosophy of Science Marie Gueguen, Stathis Psillos

PDF 54

Duhem: Images of Science, Historical Continuity, and the First Crisis in Physics Michael Liston

PDF 73

Duhem in Pre-War Italian Philosophy: The Reasons of an Absence Roberto Maiocchi

PDF 85

Was Pierre Duhem an Esprit de finesse? Víctor Manuel Hernández

PDF 93

Was Duhem Justified in not Distinguishing Between Physical and Chemical Atomism? Paul Needham

PDF 108

Bon sens and noûs Roberto Estrada Olguin

PDF 112

Duhem’s Legacy for the Change in the Historiography of Science: An Analysis Based on Kuhn’s Writings Amélia Oliveira

PDF 127

Poincaré and Duhem: Resonances in their First Epistemological Reflections João Príncipe

PDF 140

Dossier - Book Reviews

Pierre Duhem: Between Physics and Metaphysics Dámian Islas Mondragon

PDF 157

The New French Edition of Pierre Duhem’s The Aim and Structure of the Physical Theory Jean-François Stoffel

PDF 160

When Historiography Met Epistemology Jean-François Stoffel

PDF 163

Articles

A Development of the Principle of Virtual Laws and its Conceptual Framework in Mechanics as Fundamental Relationship between Physics and Mathematics Raffaele Pisano

PDF 166

Michael Scot and the Four Rainbows Tony Scott

PDF 204

Galileo and the Medici: Post-Renaissance Patronage or Post-Modern Historiography Michael Segre

PDF 226

Interviews

Interview: Helge Kragh Gustavo Rodrigues Rocha, Helge Kragh

PDF 233

Book Reviews

Galileo as a Critic of the Arts Hallhane Machado

PDF 238

A Contribution to the Newtonian Scholarship: The “Jesuit Edition” of Isaac Newton’s Principia, a research in progress by Paolo Bussotti and Raffaele Pisano Gustavo Rodrigues Rocha

PDF 242

esprit de géométrie & esprit de finesse

Pascal, Blaise. Pensées. Translated by Roger Ariew. Hackett Publishing Company, Inc., 2004:

    Some draw consequences well from a few principles, and this is rightness of thinking.
    Others draw well the consequences of things involving many principles. For example, the former understand well the effects of water, which involve few principles; but these consequences are so subtle that only acute right thinking can get to them. And, in spite of that, these people might not be great geometers, because geometry comprises a great number of principles, and a mind may be of such a nature as to be able to penetrate easily to the bottom of a few principles without in the least being able to penetrate those things involving many principles.
    There are therefore two kinds of minds: the one, penetrating rapidly and deeply the consequences of principles, is the intuitive mind [esprit de finesse]; the other, grasping a great number of principles without confusing them, is the geometric mind [esprit de géométrie]. The first has strength and rightness of mind, the second breadth of mind. Now, one can exist without the other; the mind can be strong and narrow, and also broad and weak.

Geometry/Intuition
Difference between the geometric and the intuitive mind

    In the one, principles are obvious, but removed from ordinary use, so that we find it difficult to turn our head in that direction, for lack of habit. But if it was turned that way ever so little, we would see the principles fully and would need to have a wholly defective mind to reason wrongly about such principles so obvious that it is almost impossible for them to notice.
    But with the intuitive mind, principles are in common use and before everybody's eyes. You have only to look, and no effort is necessary; it is only a question of good sight. But it must be good, because the principles are so subtle and numerous that it is almost impossible but that some escape notice. Now the omission of one principle leads to error. Thus you must have very clear sight to see all the principles, as well as an accurate mind to avoid reasoning falsely from known principles.
    All geometers would then be intuitive if they had clear sight, for they do not reason wrongly from principles known to them. And intuitive minds would be geometric if they could bend their thinking to the principles of geometry to which they are unaccustomed.
    The reason, then, that some intuitive minds are not geometric is that they simply cannot turn their attention to the principles of geometry. But the reason that geometers are not intuitive is that they do not see what is before them, and that, accustomed to the exact and plain principles of geometry, and not reasoning until they have clearly seen and handled their principles, they are lost in matters of intuition, where the principles do not allow such handling. The principles are scarcely seen; they are felt rather than seen; there is endless difficulty in making them felt by those who do not themselves apprehend them. These principles are so delicate and numerous that a delicate and clear sense is needed to apprehend them, and to judge rightly and correctly according to this feeling, without most often being able to demonstrate them in order as in geometry; because the principles are not known to us in this way and because it would be an endless task to undertake it. We must see the matter at once, at a glance, and not by a process of reasoning, at least up to a point. And thus it is rare for geometers to be intuitive and for intuitive people to be geometers, because geometers want to treat matters of intuition geometrically and make themselves ridiculous, wanting to begin by definitions and then by principles, which is not the way to proceed in this kind of reasoning. Not that the mind does not do this, but it does so tacitly, naturally, and without art, for its expression surpasses all men, and only a few can apprehend it.
    Intuitive minds, on the contrary, being thus accustomed to judge at a single glance, when presented with propositions of which they understand nothing and the paths to which consist of such sterile definitions and principles, which they are not accustomed to see in such detail, are so surprised that they are repelled and disheartened.
    But false minds are never either intuitive or geometrical.
    Geometers who are only geometers, then, have rightness of mind, provided all things are explained to them by means of definitions and principles; otherwise they are wrong and insufferable, for they are only right when the principles are quite clear.
    And intuitive minds that are only intuitive cannot have the patience to reach the first principles of speculative and imaginative things, which they have never seen in the world and which are altogether out of the common.

Physics & Metascience (Metaphysics)

George Mason University physicist (and author of The Theory of Almost Everything) Robert Oerter, discussing act in potency in in physics, writes "it seems to me that the concepts of time and change are metaphysically prior to those of potentiality."

My response:

The French physicist, philosopher and historian of physics Pierre Duhem would agree with you, Dr. Oerter, that physical theories do not depend upon a choice of metaphysics. Duhem masterfully shows this, with many historical examples, in his classic philosophy of science work The Aim and Structure of Physical Theory (excerpt). He also treats this in "Physics & Metaphysics," "Physics of a Believer," and this excerpt from To Save the Phenomena.

His reply:

Thanks, that's very helpful. From the second link:

"That Physics Logically Precedes Metaphysics

...We cannot come to know the essence of things except insofar as that essence is the cause and foundation for phenomena and the laws that govern them. The study of phenomena and laws must therefore precede the investigation of causes."

That's what I was groping for in my attempts to answer Feser.

However, I think there's a distinction that must be made between the metaphysical essences that Duhem is talking about and the metaphysical principles that Feser is talking about. Don't we need concepts of cause and change before we can even begin a physical investigation?

My response:

Your question appears to be a question on the method and division of the sciences. Boethius, following Aristotle, proposed that the "Speculative sciences may be divided into three kinds: physics, mathematics, and metaphysics.":

1. Physics [(the natural sciences)] deals with that which is in motion and material [(ens mobile or "mobile being")].
2. Mathematics deals with that which is material and not in motion [(∵ mathematical objects, or "mathematicals," do not move or change)].
3. Metascience deals with that which is not in motion nor material.

(cf. §II of his De Trinitate)

In this context, Thomas Aquinas writes in his Division and methods of the sciences, a commentary on Boethius's De Trinitate questions V and VI (my adapted translation follows):

q. 5 a. 1 objection 9: That science on which others depend must be prior to them. Now all the other sciences depend on metascience because it is its business to prove their principles. Therefore Boethius should have placed metascience before the others.

reply to objection 9: Although metascience is by nature the first of all the sciences, with respect to us the other sciences come before it. For as Avicenna says, the position of metascience is that it be learned after the natural sciences, which explain many things used by metascience, such as generation, corruption, motion, and the like [(e.g., actuality, potentiality, matter, form, etc.)]. It should also be learned after mathematics […]. […] Nor is there necessarily a vicious circle because metascience presupposes conclusions proved in the other sciences while it itself proves their principles. For the principles that another science (such as natural philosophy) takes from first philosophy [(i.e., from metascience)] do not prove the points which the first philosopher [(metascientist)] takes from the natural philosopher, but they are proved through other self-evident principles. Similarly, the first philosopher does not prove the principles he gives the natural philosopher by principles he receives from him, but by other self-evident principles. So there is no vicious circle in their definitions. Moreover, the sensible effects on which the demonstrations of natural science are based are more evident to us in the beginning. But when we come to know the first causes through them, these causes will reveal to us the reason for the effects, from which they were proved by a demonstration quia [(i.e., a demonstration a posteriori, a demonstration from effects to causes)]. In this way natural science also contributes something to metascience, and nevertheless it is metascience that explains its principles. That is why Boethius places metascience last, because it is the last relative to us (quoad nos).

See The Way toward Wisdom by Benedict Ashley (read the first chapter, this excerpt, John Deely's review). His main theses are that:

1. the natural sciences are epistemologically prior to metaphysics  
2. metaphysics, which he proposes we term "metascience," is the true philosophy of science.

Historical Method in Physics

The following email exchange with a professor in the State of Israel who studies physics education makes me really wonder if there is something flawed with the way physics is taught today (cf. "Why No 'New Einstein'?"). Out of all disciplines with PhDs, graduate students are obtaining fewer and fewer PhDs in physics than in any other field and more and more in psychology. There must be a reason for this. I wrote:

Dr. Galili,

I was glad to see that you do research following the admonition of Pierre Duhem in your "HISTORY OF PHYSICS AS A TOOL FOR TEACHING:"

The legitimate, sure and fruitful method of preparing a student to receive a physical hypothesis is the historical method. To retrace the transformations through which the empirical matter accrued while the theoretical form was first sketched; to describe the long collaboration by means of which common sense and deductive logic analyzed this matter and modeled that form until one was exactly adapted to the other: that is the best way, surely even the only way, to give to those studying physics a correct and clear view of the very complex and living organization of this science.

(And apparently Mach's "textbooks in mechanics and optics that adopted this approach remain to be valuable and interesting teaching resources.")

Your studies seem to focus on physics in secondary education. Has the historical method been applied in undergraduate and graduate physics programs? Do you do research on this?

I am a graduate physics student, and graduate-level physics seems mostly taught to a certain type of learner, i.e., to one who "learns by doing," who learns solely by solving written problems. I am from the United States, and this seems to be the predominant method most of the physics departments employ in training their students. Are there graduate programs—besides those HPS departments—that do things differently, who maybe even implement the historical method?

Thank you

(The quote is from Duhem's Aim and Structure of Physical Theory pg. 268.) He responded:

Thank you for your message and interest to my work.
The subject you write about actually presents a sensitive discourse in physics teaching. Nothing is harder than to cause a conceptual change to physics educators,and researchers especially. Currently, the prevailing mode of teaching adopts profession oriented pragmatic approach which is very instrumentalist although widely uses the rhetoric of conceptual understanding. Within this understanding problem solving and modeling occupy the central role. I hold a different perspective oriented to physics education (different from physics as a profession). Such education aims at learning physics as a special culture people create in making sense of nature and natural phenomenon.
Not to cause people much negative emotions and resistance, I prefer to investigate secondary school students. However, I am convinced that my materials are applicable and perhaps even more effective for university students who deal with these the same subjects. They all need good conceptual bases in the physics they learn. Complex formalism does not replace understanding fundamentals. Such is, for example the issue of weight definition. Although included in middle school physics curriculum, it presents a great controversy in university physics textbooks of physics.
Best regards,
igal

Where did this "profession oriented pragmatic approach which is very instrumentalist although widely uses the rhetoric of conceptual understanding" originate? Perhaps the pragmatism originates from the progressive education movement of John Dewey (cf. these articles by Fr. Hardon, S.J., on Dewey: Part 1, 2, and 3)? Duhem's philosophy of science is considered instrumentalist, yet he would agree that "modeling," which he criticized the English physicists like Maxwell for advocating as physical explanations, should not "occupy the central role." And "the rhetoric of conceptual understanding?" Rhetoric? Would all physicists agree what they do is rhetoric? Feynman might have, because he said he won the Nobel prize for "sweeping [e.g., inconsistencies] under the rug." Perhaps all the psychology PhDs will finally get it across to physicists what it actually means to know and to understand, assuming an epistemology grounded on sound philosophy,

Interface between Theology and the Other Sciences

Related to this is again the question of why intellectual knowledge must come through the senses (Nothing is in the intellect that is not first in the senses: Nihil est in intellectu quod non prius in sensu.). The faithful hold by faith that:

For the invisible things of him, from the creation of the world, are clearly seen, being understood by the things that are made; his eternal power also, and divinity.

—Romans 1:20

As well as these:

If anyone shall have said that the one true God, our Creator and our Lord, cannot be known with certitude by those things which have been made, by the natural light of human reason: let him be anathema

—Denzinger 1806

The same Holy Mother Church holds and teaches that God, the beginning and end of all things, can be known with certitude by the natural light of human reason from created things; "for the invisible things of him, from the creation of the world, are clearly seen, being understood by the things that are made" [Rom 1:20]; nevertheless, it has pleased His wisdom and goodness to reveal Himself and the eternal decrees of His will to the human race in another and supernatural way, as the Apostle says: "God, who at sundry times and in divers manners, spoke in times past to the fathers by the prophets, last of all, in these days hath spoken to us by His Son" [Heb. 1:1].

—Denzinger 1785

Most relevant is this:

All knowledge of God, even natural knowledge, even in the pagan philosophers, cannot come except from God; and without grace knowledge produces nothing but presumption, vanity, and opposition to God Himself, instead of the affections of adoration, gratitude, and love.

—Denzinger 1391

How does the study of God's creatures, by doing physics in the broad sense of studying the natural world, lead to knowledge of Him? St. Thomas elucidates this:

Chapter 1

THE CONNECTION BETWEEN THE FOLLOWING CONSIDERATIONS AND THE PRECEDING ONES

“I meditated upon Your works: I meditated upon the works of Your hands” (Ps. 142-5).

[1] Of no thing whatever can a perfect knowledge be obtained unless its operation is known, because the measure and quality of a thing’s power is judged from the manner and type of its operation, and its power, in turn, manifests its nature; for a thing’s natural aptitude for operation follows upon its actual possession of a certain kind of nature.

[2] There are, however, two sorts of operation, as Aristotle teaches in Metaphysics IX [8]: one that remains in the agent and is a perfection of it, as the act of sensing, understanding, and willing; another that passes over into an external thing, and is a perfection of the thing made as a result of that operation, the acts of heating, cutting and building, for example.

[3] Now, both kinds of operation belong to God: the former, in that He understands, wills, rejoices, and loves; the latter, in that He brings things into being, preserves them, and governs them. But, since the former operation is a perfection of the operator, the latter a perfection of the thing made, and since the agent is naturally prior to the thing made and is the cause of it, it follows that the first of these types of operation is the ground of the second, and naturally precedes it, as a cause precedes its effect. Clear evidence of this fact, indeed, is found in human affairs; for in the thought and will of the craftsman lie the principle and plan of the work of building.

[4] Therefore, as a simple perfection of the operator, the first type of operation claims for itself the name of operation, or, again, of action; the second, as being a perfection of the thing made, is called making so that the things which a craftsman produces by action of this kind are said to be his handiwork.

[5] Of the first type of operation in God we have already spoken in the preceding Book of this work, where we treated of the divine knowledge and will. Hence, for a complete study of the divine truth, the second operation, whereby things are made and governed by God, remains to be dealt with.

[6], In fact, this order we can gather from the words quoted above. For the Psalmist first speaks of meditation upon the first type of operation, when he says: “I have meditated on all your operations”; thus, operation is here referred to the divine act of understanding and will. Then he refers to meditation on God’s works: “and I meditated on the works of Your hands”; so that by “the works of Your hands” we understand heaven and earth, and all that is brought into being by God, as the handiwork produced by a craftsman.

Chapter 2

THAT THE CONSIDERATION OF CREATURES IS USEFUL FOR INSTRUCTION OF FAITH

[1] This sort of meditation on the divine works is indeed necessary for instruction of faith in God.

[2] First, because meditation on His works enables us in game measure to admire and reflect upon His wisdom. For things made by art are representative of the art itself, being made in likeness to the art. Now, God brought things into being by His wisdom; wherefore the Psalm (103:24) declares: “You made all things in wisdom.” Hence, from reflection upon God’s works we are able to infer His wisdom, since, by a certain communication of His likeness, it is spread abroad in the things He has made. For it is written: “He poured her out,” namely, wisdom, “upon all His works” (Eccli. 1:10). Therefore, the Psalmist, after saying: “Your knowledge is become wonderful to me: it is high, and I cannot reach it,” and after referring to the aid of the divine illumination, when he says: “Night shall be my light,” etc., confesses that he was aided in knowing the divine wisdom by reflection upon God’s works, saying: “Wonderful are Your works, and my soul knows right well” (Ps. 138:6, 11, 14).

[3] Secondly, this consideration [of God’s works] leads to admiration of God’s sublime power, and consequently inspires in men’s hearts reverence for God. For the power of the worker is necessarily understood to transcend the things made. And so it is said: “If they,” namely, the philosophers, “admired their power and effects,” namely of the heavens, stars, and elements of the world, “let them understand that He that made them is mightier than they” (Wis. 13:4). Also it is written: “The invisible things of God are clearly seen, being understood by the things that are made: His eternal power also and divinity” (Rom. 1:20). Now, the fear and reverence of God result from this admiration. Hence, it is said: “Great is Your name in might. Who shall not fear You, O King of Nations?” (Jer. l0:6-7).

[4] Thirdly, this consideration incites the souls of men to the love of God’s goodness. For whatever goodness and perfection is distributed to the various creatures, in partial or particular measure, is united together in Him universally, as in the source of all goodness, as we proved in Book I. If, therefore, the goodness, beauty, and delightfulness of creatures are so alluring to the minds of men, the fountainhead of God’s own goodness, compared with the rivulets of goodness found in creatures, will draw the enkindled minds of men wholly to Itself. Hence it is said in the Psalm (91:5): “You have given me, O Lord, a delight in Your doings, and in the works of Your hands I shall rejoice.” And elsewhere it is written concerning the children of men: “They shall be inebriated with the plenty of Your house,” that is, of all creatures, “and You shall make them drink of the torrent of Your pleasure: for with You is the fountain of life” (Ps. 35:9-10). And, against certain men, it is said: “By these good things that are seen,” namely, creatures, which are good by a kind of participation, “they could not understand Him that is” (Wis. 13:1), namely, truly good; indeed, is goodness itself, as was shown in Book I.

[5] Fourthly, this consideration endows men with a certain likeness to God’s perfection. For it was shown in Book I that, by knowing Himself, God beholds all other things in Himself. Since, then, the Christian faith teaches man principally about God, and makes him know creatures by the light of divine revelation, there arises in man a certain likeness of God’s wisdom. So it is said: “But we all beholding the glory of the Lord with open face, are transformed into the same image” (2 Cor. 3:18).

[6] It is therefore evident that the consideration of creatures has its part to play in building the Christian faith. And for this reason it is said: “I will remember the works of the Lord, and I will declare the things I have seen: by the words of the Lord are His works” (Sirach 42:15).

Chapter 3

THAT KNOWLEDGE OF THE NATURE OF CREATURES SERVES TO DESTROY ERRORS CONCERNING GOD

[1] The consideration of creatures is further necessary, not only for the building up of truth, but also for the destruction of errors. For errors about creatures sometimes lead one astray from the truth of faith, so far as the errors are inconsistent with true knowledge of God. Now, this happens in many ways.

[2] First, because through ignorance of the nature of creatures men are sometimes so far perverted as to set up as. the first cause and as God that which can only receive its being from something else; for they think that nothing exists beyond the realm of visible creatures. Such were those who identified God with this, that, and the other kind of body; and of these it is said: “Who have imagined either the fire, or the wind, or the swift air, or the circle of the stars, or the great water, or the sun and moon to be the gods” (Wis. 13: 2).

[3] Secondly, because they attribute to certain creatures that which belongs only to God. This also results from error concerning creatures. For what is incompatible with a thing’s nature is not ascribed to it except through ignorance of its nature—as if man were said to have three feet. Now, what belongs solely to God is incompatible with the nature of a created thing, just as that which is exclusively man’s is incompatible with another thing’s nature. Thus, it is from ignorance of the creature’s nature that the aforesaid error arises. And against this error it is said: “They gave the incommunicable name to stones and wood” (Wis. 14:21). Into this error fell those who attribute the creation of things, or knowledge of the future, or the working of miracles to causes other than God.

[4] Thirdly, because through ignorance of the creature’s nature something is subtracted from God’s power in its working upon creatures. This is evidenced in the case of those who set up two principles of reality; in those who assert that things proceed from God, not by the divine will, but by natural necessity; and again, in those who withdraw either all or some things from the divine providence, or who deny that it can work outside the ordinary course of things. For all these notions are derogatory to God’s power. Against such persons it is said: “Who looked upon the Almighty as if He could do nothing” (Job 22:17), and: “You show Your power, when men will not believe You to be absolute in power” (Wis. .12: 17).

[5] Fourthly, through ignorance of the nature of things, and, consequently, of his own place in the order of the universe, this rational creature, man, who by faith is led to God as his last end, believes that he is subject to other creatures to which he is in fact superior. Such is evidently the case with those who subject human wills to the stars, and against these it is said: “Be not afraid of the signs of heaven, which the heathens fear” (Jer. 10:2); and this is likewise true of those who think that angels are the creators of souls, that human souls are mortal, and, generally, of persons who hold any similar views derogatory to the dignity of man.

[6] It is, therefore, evident that the opinion is false of those who asserted that it made no difference to the truth of the faith what anyone holds about creatures, so long as one thinks rightly about God, as Augustine tells us in his book On the Origin of the Soul [De anima et ejus origine, IV, 4]. For error concerning creatures, by subjecting them to causes other than God, spills over into false opinion about God, and takes men’s minds away from Him, to whom faith seeks to lead them.

[7] For this reason Scripture threatens punishment to those who eff about creatures, as to unbelievers, in the words of the Psalm (27:5): “Because they have not understood the works of the Lord and the operations of His hands, You shall destroy them, and shall not build them up”; and: “These things they thought and were deceived,” and further on: “They did not esteem the honor of holy Souls” (Wis. 7:2122).

Chapter 4

THAT THE PHILOSOPHER AND THE THEOLOGIAN CONSIDER CREATURES IN DIFFERENT WAYS

[1] Now, from what has been said it is evident that the teaching of the Christian faith deals with creatures so far as they reflect a certain likeness of God, and so far as error concerning them leads to error about God. And so they are viewed in a different light by that doctrine and by human philosophy. For human philosophy considers them as they are, so that the different parts of philosophy are found to correspond to the different genera of things. The Christian faith, however, does not consider them as such; thus, it regards fire not as fire, but as representing the sublimity of God, and as being directed to Him in any way at all. For as it is said: “Full of the glory of the Lord is His work. Did the Lord not make the saints declare all His wonderful works?” (Sirach 42: 16-17)

[2] For this reason, also, the philosopher and the believer consider different matters about creatures. The philosopher considers such things as belong to them by nature-the upward tendency of fire, for example; the believer, only such things as belong to them according as they are related to God—the fact, for instance, that they are created by God, are subject to Him, and so on.

[3] Hence, imperfection is not to be imputed to the teaching of the faith if it omits many properties of things, such as the figure of the heaven and the quality of its motion. For neither does the natural philosopher consider the same characters of a line as the geometrician, but only those that accrue to it as terminus of a natural body.

[4] But any things concerning creatures that are considered in common by the philosopher and the believer are conveyed through different principles in each case. For the philosopher takes his argument from the proper causes of things; the believer, from the first cause—for such reasons as that a thing has been handed down in this manner by God, or that this conduces to God’s glory, or that God’s power is infinite. Hence, also, [the doctrine of the faith] ought to be called the highest wisdom, since it treats of the highest Cause; as we read in Deuteronomy (4:6): “For this is your wisdom and understanding in the sight of nations.” And, therefore, human philosophy serves her as the first wisdom. Accordingly, divine wisdom sometimes argues from principles of human philosophy. For among philosophers, too, the first philosophy utilizes the teachings of all the sciences in order to realize its objectives.

[5] Hence again, the two kinds of teaching do not follow the same order. For in the teaching of philosophy, which considers creatures in themselves and leads us from them to the knowledge of God, the first consideration is about creatures; the last, of God. But in the teaching of faith, which considers creatures only in their relation to God, the consideration of God comes first, that of creatures afterwards. And thus the doctrine of faith is more perfect, as being more like the knowledge possessed by God, who, in knowing Himself, immediately knows other things.

[6] And so, following this order, after what has been said in Book I about God in Himself, it remains for us to treat of the things which derive from Him.

—Contra Gentiles, lib. 2 cap. 1-4

Sense Knowledge

We have seen the amazing relationship of faith and sense knowledge in the context of "credo ut intelligam" versus "intelligo ut credam" and the story of Doubting St. Thomas the Apostle (John 20:24-29).

Here I analyze St. Thomas Aquinas's Summa Theologica article that, contrary to most moderns who are steeped in a Cartesian idealism—viz., who think everything is in our heads—intellectual knowledge does indeed come from the senses. Overcoming modern Manicheans' and Albigenses' denial of this—i.e., that they think a human being is not both a body and an intellectual soul but just a soul trapped in a body, hence rationalizing any misuse of the human body, e.g., pornography, slavery, contraception, abortion, because the apparently evil body has no affect on oneself nor on one's soul—is vitally important both for society and for the proper development of modern physics, as the Institute of Advanced Physics recognizes and promotes. Nothing is in the intellect that is not first in the senses: Nihil est in intellectu quod non prius in sensu. (Refer to this post for an overview of this "Epistemology of Modern Physics" series.)

Article 6. Whether intellectual knowledge is derived from sensible things?

Objection 1. It would seem that intellectual knowledge is not derived from sensible things. For Augustine says (QQ. 83, qu. 9) that "we cannot expect to learn the fulness of truth from the senses of the body." This he proves in two ways. First, because "whatever the bodily senses reach, is continually being changed; and what is never the same cannot be perceived." Secondly, because, "whatever we perceive by the body, even when not present to the senses, may be present to the imagination, as when we are asleep or angry: yet we cannot discern by the senses, whether what we perceive be the sensible object or the deceptive image thereof. Now nothing can be perceived which cannot be distinguished from its counterfeit." And so he concludes that we cannot expect to learn the truth from the senses. But intellectual knowledge apprehends the truth. Therefore intellectual knowledge cannot be conveyed by the senses.

[So would St. Augustine deny that anything can be sensed? Would he say that the senses always are a faulty and untrustworthy assessor of what is real?]

Objection 2. Further, Augustine says (Gen. ad lit. xii, 16): "We must not think that the body can make any impression on the spirit, as though the spirit were to supply the place of matter in regard to the body's action; for that which acts is in every way more excellent than that which it acts on." Whence he concludes that "the body does not cause its image in the spirit, but the spirit causes it in itself." Therefore intellectual knowledge is not derived from sensible things.

[This seems to be a plausible argument. If the soul animates the body, then what effect can the body have on the soul? Is it a direct effect, or does the body change such that the soul animating it must correspondingly adapt to the change? Is this how it would communicate sense knowledge to the soul? Affecting how the soul can animate the body?]

Objection 3. Further, an effect does not surpass the power of its cause. But intellectual knowledge extends beyond sensible things: for we understand some things which cannot be perceived by the senses. Therefore intellectual knowledge is not derived from sensible things.

[I suppose this is related to the fact that senses deal with particulars—"this atom," "that dog", etc.—than with universals—"atom-ness," "dog-ness," etc.—generalized from particulars. The human intellectual soul can only do this.]

On the contrary, The Philosopher says (Metaph. i, 1; Poster. ii, 15) that the principle of knowledge is in the senses.

[The principle of knowledge, not just a principle. This seems like a strong statement. Not only does the fact that 2+2=4 originate from the senses but so does the fact that something cannot both be and not be at the same time and in the same way: the law of non-contradition. So, also, does the fact that God exists come from the senses!]

I answer that, On this point the philosophers held three opinions. For Democritus held that "all knowledge is caused by images issuing from the bodies we think of and entering into our souls," as Augustine says in his letter to Dioscorus (cxviii, 4). And Aristotle says (De Somn. et Vigil.) that Democritus held that knowledge is cause by a "discharge of images." And the reason for this opinion was that both Democritus and the other early philosophers did not distinguish between intellect and sense, as Aristotle relates (De Anima iii, 3). Consequently, since the sense is affected by the sensible, they thought that all our knowledge is affected by this mere impression brought about by sensible things. Which impression Democritus held to be caused by a discharge of images.

[So, in a way, Democritus thought that we had a sort of angelic, direct knowledge of objects via a "discharge of images" coming from them; thus, we knowledge not mediated by the senses. But this is just pushing the question into the realm of the unknown: What exactly are these images that are discharged? How are they distinguished? Does every soul interpret them similarly? How would you know? This seems to be a subtle form of Cartesian idealism.]

Plato, on the other hand, held that the intellect is distinct from the senses: and that it is an immaterial power not making use of a corporeal organ for its action.[Yes, not even the brain] And since the incorporeal cannot be affected by the corporeal, he held that intellectual knowledge is not brought about by sensible things affecting the intellect, but by separate intelligible forms being participated by the intellect, as we have said above (4,5) [and it would seem in the previous paragraph, too]. Moreover he held that sense is a power operating of itself. Consequently neither is sense, since it is a spiritual power, affected by the sensible: but the sensible organs are affected by the sensible, the result being that the soul is in a way roused to form within itself the species of the sensible. [How exactly?] Augustine seems to touch on this opinion (Gen. ad lit. xii, 24) where he says that the "body feels not, but the soul through the body, which it makes use of as a kind of messenger, for reproducing within itself what is announced from without." [This might be akin to what we said in the first comment above.] Thus according to Plato, neither does intellectual knowledge proceed from sensible knowledge, nor sensible knowledge exclusively from sensible things; but these rouse the sensible soul to the sentient act, while the senses rouse the intellect to the act of understanding.

Aristotle chose a middle course. For with Plato he agreed that intellect and sense are different. But he held that the sense has not its proper operation without the cooperation of the body [Now this is more reasonable because how can the senses not be corporeal?]; so that to feel is not an act of the soul alone, but of the "composite." [Yes, the body and soul, when a human is alive, are inextricably connected.] And he held the same in regard to all the operations of the sensitive part. Since, therefore, it is not unreasonable that the sensible objects which are outside the soul should produce some effect in the "composite," Aristotle agreed with Democritus in this, that the operations of the sensitive part are caused by the impression of the sensible on the sense: not by a discharge, as Democritus said, but by some kind of operation. [Through the physical] For Democritus maintained that every operation is by way of a discharge of atoms [not in the modern sense of "atom," though], as we gather from De Gener. i, 8. But Aristotle held that the intellect has an operation which is independent of the body's cooperation. Now nothing corporeal can make an impression on the incorporeal. [Agreed] And therefore in order to cause the intellectual operation according to Aristotle, the impression caused by the sensible does not suffice, but something more noble is required, for "the agent is more noble than the patient," as he says (De Gener. i, 5). Not, indeed, in the sense that the intellectual operation is effected in us by the mere impression of some superior beings, as Plato held; but that the higher and more noble agent which he calls the active intellect, of which we have spoken above (79, 3,4) [See Sentencia De anima, lib. 3 l. 10.] causes the phantasms received from the senses to be actually intelligible, by a process of abstraction.

According to this opinion, then, on the part of the phantasms, intellectual knowledge is caused by the senses. But since the phantasms cannot of themselves affect the passive intellect, and require to be made actually intelligible by the active intellect, it cannot be said that sensible knowledge is the total and perfect cause of intellectual knowledge, but rather that it is in a way the material cause.

[Wow, so sense knowledge is like a material cause of intellectual knowledge. What would the formal cause be like, then? The phantasms? The light of reason? The active intellect? The fact that the passive and active intellect is one of the hardest things to understand definitely sheds light on the mystery of the relation between the senses and the soul, but it cannot disprove that sense knowledge is not like the form of intellectual knowledge.]

Reply to Objection 1. Those words of Augustine mean that we must not expect the entire truth from the senses. For the light of the active intellect is needed, through which we achieve the unchangeable truth of changeable things, and discern things themselves from their likeness.

["[T]he light of the active intellect is needed." What about the principles afforded by Revelation, the truths of faith?]

Reply to Objection 2. In this passage Augustine speaks not of intellectual but of imaginary knowledge. And since, according to the opinion of Plato, the imagination has an operation which belongs to the soul only, Augustine, in order to show that corporeal images are impressed on the imagination, not by bodies but by the soul, uses the same argument as Aristotle does in proving that the active intellect must be separate, namely, because "the agent is more noble than the patient." And without doubt, according to the above opinion, in the imagination there must needs be not only a passive but also an active power. But if we hold, according to the opinion of Aristotle, that the action of the imagination, is an action of the "composite," there is no difficulty; because the sensible body is more noble than the organ of the animal, in so far as it is compared to it as a being in act to a being in potentiality; even as the object actually colored is compared to the pupil which is potentially colored. It may, however, be said, although the first impression of the imagination is through the agency of the sensible, since "fancy is movement produced in accordance with sensation" (De Anima iii, 3), that nevertheless there is in man an operation which by synthesis and analysis forms images of various things, even of things not perceived by the senses. And Augustine's words may be taken in this sense.

Reply to Objection 3. Sensitive knowledge is not the entire cause of intellectual knowledge. And therefore it is not strange that intellectual knowledge should extend further than sensitive knowledge.

[What is the rest of the cause? "[T]he light of the active intellect?"]

—St. Thomas Aquinas's Summa Theologica Iª q. 84 a. 6 with my commentary in [red]

See future posts for the continuation of the commentary.

Epistemology of Modern Physics

How does one understand the physical world? How does one know he understands it, viz., what is his epistemology? To answer these questions from a modern physicist's perspective, I comment below on questions 84 through 89 of the first part of St. Thomas Aquinas's Summa Theologica.

Here is a brief overview of what these questions address:

Question 84. How the soul while united to the body understands corporeal things beneath it

1. Does the soul know bodies through the intellect?
2. Does it understand them through its essence, or through any species?
3. If through some species, are the species of all things intelligible naturally innate in the soul?
4. Are these species derived by the soul from certain separate immaterial forms?
5. Does our soul see in the eternal ideas all that it understands?
6. Does it acquire intellectual knowledge from the senses?
7. Can the intellect, through the species of which it is possessed, actually understand, without turning to the phantasms?
8. Is the judgment of the intellect hindered by an obstacle in the sensitive powers?

Question 85. The mode and order of understanding

1. Does our intellect understand by abstracting the species from the phantasms?
2. Are the intelligible species abstracted from the phantasms what our intellect understands, or that whereby it understands?
3. Does our intellect naturally first understand the more universal?
4. Can our intellect know many things at the same time?
5. Does our intellect understand by the process of composition and division?
6. Can the intellect err?
7. Can one intellect understand better than another?
8. Does our intellect understand the indivisible before the divisible?

Question 86. What our intellect knows in material things

1. Does it know singulars?
2. Does it know the infinite?
3. Does it know contingent things?
4. Does it know future things?

Question 89. The knowledge of the separated soul

1. Can the soul separated from the body understand?
2. Does it understand separate substances?
3. Does it understand all natural things?
4. Does it understand individuals and singulars?
5. Do the habits of knowledge acquired in this life remain?
6. Can the soul use the habit of knowledge here acquired?
7. Does local distance impede the separated soul's knowledge?
8. Do souls separated from the body know what happens here?

Some terminology:

• "Soul," or anima in Latin, means "The principle of thought and action in man, commonly regarded as an entity distinct from the body; the spiritual part of man in contrast to the purely physical." (Oxford English Dictionary). The soul is the form of the human body and is roughly synonymous with "mind."
• "Phantasm" is a philosophical term for "A mental image, appearance, or representation, considered as the immediate object of sense perception (as distinct from the external thing itself or, in Platonic thought, its underlying form), or as the means by which the mind grasps the intelligible form of an object." (Oxford English Dictionary).
• "Motion" is "Any kind of change; becoming." (Oxford English Dictionary).
• "Angels" are "intellectual beings."

Definitions for other terms will arise in the commentary itself.

Beginning with the first article of Question 84, again with my commentary in [red]:

Article 1. Whether the soul knows bodies through the intellect?

[How else would one know them? Through the means of physics experiments and instruments only?]

Objection 1. It would seem that the soul does not know bodies through the intellect. For Augustine says (Soliloq. ii, 4) that "bodies cannot be understood by the intellect; nor indeed anything corporeal unless it can be perceived by the senses." He says also (Gen. ad lit. xii, 24) that intellectual vision is of those things that are in the soul by their essence. But such are not bodies. Therefore the soul cannot know bodies through the intellect.

[Thus St. Augustine would agree that one cannot understand, e.g., the hydrogen atom without first performing experiments with instruments that make its effects perceptible to us; viz., we cannot understand corporeal objects with our intellects only, as Aristotle tried: Theoretical physics without experimentation is pure speculation.]

Objection 2. Further, as sense is to the intelligible, so is the intellect to the sensible. But the soul can by no means, through the senses, understand spiritual things, which are intelligible. Therefore by no means can it, through the intellect, know bodies, which are sensible.

[Atheists, e.g., would deny that spiritual things are intelligible, though.]

Objection 3. Further, the intellect is concerned with things that are necessary and unchangeable. But all bodies are mobile and changeable. Therefore the soul cannot know bodies through the intellect.

[That "the intellect is concerted with things that are necessary and unchangeable" is another way of saying that the intellect strives for universal, certain knowledge. It tries to understand not just why, e.g., this particular measured hydrogen atom displays certain properties but what the universal nature of all hydrogen atoms must necessarily be.]

On the contrary, Science is in the intellect. If, therefore, the intellect does not know bodies, it follows that there is no science of bodies; and thus perishes natural science, which treats of mobile bodies.

[No natural scientist can deny this claim. Also, by "mobile bodies" St. Thomas means changeable ones.]

I answer that, It should be said in order to elucidate this question, that the early philosophers, who inquired into the natures of things, thought there was nothing in the world save bodies. And because they observed that all bodies are mobile, and considered them to be ever in a state of flux, they were of opinion that we can have no certain knowledge of the true nature of things. For what is in a continual state of flux, cannot be grasped with any degree of certitude, for it passes away ere the mind can form a judgment thereon: according to the saying of Heraclitus, that "it is not possible twice to touch a drop of water in a passing torrent," as the Philosopher relates (Metaph. iv, Did. iii, 5).

[It is interesting that St. Thomas says that "that the early philosophers, who inquired into the natures of things, thought there was nothing in the world save bodies." Many modern scientists, from Descartes to Galileo to those in the present today, still believe in this claim. They believe in materialism, which says only matter and its movements exist, and in positivism, which holds that empirical science can justify every rational truth and therefore denies the supernatural or metaphysical, that which is "beyond physics." Galileo, being a mechanist, wrote extensively on how there is nothing more to the nature of, e.g., a feather than its mechanical movement, and this is all that is necessary for describing how we sense its tickling the skin.]

After these came Plato, who, wishing to save the certitude of our knowledge of truth through the intellect, maintained that, besides these things corporeal, there is another genus of beings, separate from matter and movement, which beings he called "species" or "ideas," by participation of which each one of these singular and sensible things is said to be either a man, or a horse, or the like. Wherefore he said that sciences and definitions, and whatever appertains to the act of the intellect, are not referred to these sensible bodies, but to those beings immaterial and separate: so that according to this the soul does not understand these corporeal things, but the separate species thereof.

[This makes more sense because the objects physicists study through the mediation of experimentation are not the same as those one directly perceives in everyday experience. Who has ever touched or tasted, e.g., a quantum wavefuction? These things are indeed in the physical realm, not the directly sensible corporeal realm; they are a "separate species."]

Now this may be shown to be false for two reasons.

First, because, since those species are immaterial and immovable, knowledge of movement and matter would be excluded from science (which knowledge is proper to natural science), and likewise all demonstration through moving and material causes.

Secondly, because it seems ridiculous, when we seek for knowledge of things which are to us manifest, to introduce other beings, which cannot be the substance of those others, since they differ from them essentially: so that granted that we have a knowledge of those separate substances, we cannot for that reason claim to form a judgment concerning these sensible things.

[Notice he says modeling "things which are to us [already] manifest" is ridiculous. He is not saying that modeling the nature of subatomic particles, e.g., is ridiculous because their nature is not manifest, hence it is necessary that we model them since we cannot directly sense them.]

Now it seems that Plato strayed from the truth because, having observed that all knowledge takes place through some kind of similitude, he thought that the form of the thing known must of necessity be in the knower in the same manner as in the thing known. Then he observed that the form of the thing understood is in the intellect under conditions of universality, immateriality, and immobility: which is apparent from the very operation of the intellect, whose act of understanding has a universal extension, and is subject to a certain amount of necessity: for the mode of action corresponds to the mode of the agent's form. Wherefore he concluded that the things which we understand must have in themselves an existence under the same conditions of immateriality and immobility.

[According to Pope Benedict XVI, modern science is Platonic. Aristotle would say that the form exists in the matter, not separate from it. It is only our intellect that abstracts different formal objects from a certain material object.]

But there is no necessity for this. For even in sensible things it is to be observed that the form is otherwise in one sensible than in another: for instance, whiteness may be of great intensity in one, and of a less intensity in another: in one we find whiteness with sweetness, in another without sweetness. In the same way the sensible form is conditioned differently in the thing which is external to the soul, and in the senses which receive the forms of sensible things without receiving matter, such as the color of gold without receiving gold. So also the intellect, according to its own mode, receives under conditions of immateriality and immobility, the species of material and mobile bodies: for the received is in the receiver according to the mode of the receiver. We must conclude, therefore, that through the intellect the soul knows bodies by a knowledge which is immaterial, universal, and necessary.

[When we understand gold, we do not have gold in our soul; rather, we have a particular formal object "in the receiver according to the mode of the receiver." This is not invented by the particular intellect, as the Kantians or Cartesians would say, nor is it equal to the material object as it would be in the intellect of an angel ("intellectual being"), which perceives things at once, not through reasoning, dividing, or composing as humans must do. For example, we consider charge separately from mass, then recompose the concepts to understand what a "charged mass" is. We start from axioms, such as in Euclidean geometry, and argue discursively to conclusions; but to angels these things are apparent at once.]

Reply to Objection 1. These words of Augustine are to be understood as referring to the medium of intellectual knowledge, and not to its object. For the intellect knows bodies by understanding them, not indeed through bodies, nor through material and corporeal species; but through immaterial and intelligible species, which can be in the soul by their own essence.

[Yes, sense-knowledge—even that obtained through empirical data and experiments—is the medium through which we ultimately gain knowledge, which ultimately resides in the soul.]

Reply to Objection 2. As Augustine says (De Civ. Dei xxii, 29), it is not correct to say that as the sense knows only bodies so the intellect knows only spiritual things; for it follows that God and the angels would not know corporeal things. The reason of this diversity is that the lower power does not extend to those things that belong to the higher power; whereas the higher power operates in a more excellent manner those things which belong to the lower power.

Reply to Objection 3. Every movement presupposes something immovable: for when a change of quality occurs, the substance remains unmoved; and when there is a change of substantial form, matter remains unmoved. Moreover the various conditions of mutable things are themselves immovable; for instance, though Socrates be not always sitting, yet it is an immovable truth that whenever he does sit he remains in one place. For this reason there is nothing to hinder our having an immovable science of movable things.

—St. Thomas Aquinas's Summa Theologica Iª q. 84 a. 1

See future posts for the continuation of the commentary.

Pasteur, Heisenberg, Pauli, and Gödel

Louis Pasteur was a "chemist, founder of physio-chemistry, father of bacteriology, inventor of bio-therapeuties."

Pasteur's faith was as genuine as his science. In his panegyric of Littré, whose fauteuil he took, he said:

Happy the man who bears within him a divinity, an ideal of beauty and obeys it; and ideal of art, and ideal of science, an ideal of country, and ideal of the virtues of the Gospel.

These words are graven above his tomb in the Institut Pasteur. In his address Pasteur said further "These are the living springs of great thoughts and great actions. Everything grows clear in the reflections from the Infinite". Some of his letters to his children breathe profound simple piety. He declared "The more I know, the more nearly is my faith that of the Breton peasant. Could I but know all I would have the faith of a Breton peasant woman." What he could not above all understand is the failure of scientists to recognize the demonstration of the existence of the Creator that there is in the world around us. He died with his rosary in his hand, after listening to the life of St. Vincent de Paul which he had asked to have read to him, because he thought that his work like that of St. Vincent would do much to save suffering children.

—Catholic Encyclopedia "Louis Pasteur"

Thus knowledge of God and his creation is much clearer and more easily obtained through faith than through natural reason:

There is a great difference between Christian philosophy and human wisdom. The latter, guided solely by the light of nature, advances slowly by reasoning on sensible objects and effects, and only after long and laborious investigation is it able at length to contemplate with difficulty the invisible things of God, to discover and understand a First Cause and Author of all things. Christian philosophy, on the contrary, so quickens the human mind that without difficulty it pierces the heavens, and, illumined with divine light, contemplates first, the eternal source of light, and in its radiance all created things: so that we experience with the utmost pleasure of mind that we have been called, as the Prince of the Apostles says, out of darkness into his admirable light, and believing we rejoice with joy unspeakable. (1 Pet. 1:8; 1 Pet. 2:9) Justly, therefore, do the faithful profess first to believe in God, whose majesty, with the Prophet Jeremias, we declare incomprehensible (Jer. 32:19). For, as the Apostle says, He dwells in light inaccessible, which no man hath seen, nor can see (1 Tim. 6:16); as God Himself, speaking to Moses, said: No man shall see my face and live (Exod. 33:20). The mind cannot rise to the contemplation of the Deity, whom nothing approaches in sublimity, unless it be entirely disengaged from the senses, and of this in the present life we art naturally incapable.*

—Catechism of the Council of Trent

* On this question see Summa Theol. Ia. xii. 11.

On today's sharp division into mutually exclusive "objective" and "subjective" realms of knowledge and natural reason versus religion, faith, or "supernatural reason," respectively, Werner Heisenberg said:

I have to admit that I do not feel happy about this division. I doubt whether any human society can in the long term live with this sharp division between knowledge and faith. [...] Then Wolfgang Pauli took up the thread of the discussion and agreed with Heisenberg's doubt, asserting in fact that this was quite certain: "The complete division between knowledge and faith is surely just a temporary stopgap measure. In western society and culture we could for instance, in the not-too-distant future, come to the point at which the parables and images that religion has used up to now are not longer convincing even for simple folk; and then, I fear, traditional morality will also very rapidly break down, and things will happen that are more frightful than anything we can yet imagine."

—Pope Benedict XVI's Truth and Tolerance

Fortunately, faith and knowledge are not divided. Because all sciences ultimately point toward understanding God or "a First Cause and Author of all things"—and since God is "the truth," i.e., the absolute Truth (John 14:6)—St. Thomas Aquinas says:

We have a more perfect knowledge of God by grace than by natural reason. Which is proved thus. The knowledge which we have by natural reason contains two things: images derived from the sensible objects; and the natural intelligible light, enabling us to abstract from them intelligible conceptions. Now in both of these, human knowledge is assisted by the revelation of grace. For the intellect's natural light is strengthened by the infusion of gratuitous light.

—Summa Theol. Ia. xii. 13, a comparison of faith and reason

Kurt Gödel's seminal 1931 paper On Formally Undecidable Propositions of Principia Mathematica and Related Systems showed that there are true propositions within formal mathematical systems that can neither be proven true nor false within their respective system. The propositions require something beyond—a sort of "faith" or outside means—to justify their truth. Thus mathematics, an invention of the human intellect, has its limitations. Similarly, the finite human mind has its limitations without the light of Divine Assistance, too—especially when it comes to understanding the Infinite, let alone the physical world. It seems Pasteur, Heisenberg, Pauli, and Gödel all recognized the finitude of natural reason and its freedom to transcend when coupled with faith.