Mulla Sadra’s Epistemology and the Philosophy of Physics

Caner K. Dagli

The George Washington University, USA




In response to the philosophical speculation that has accompanied the empirical findings of twentieth-century physics, the contemporary philosopher and mathematician Wolfgang Smith has introduced a distinction between what he calls the corporeal and physical worlds, the former being that which is accessible to us through our own senses and the latter being that which is accessible to us through the modus operandi of physics, and which most notably contains the entirety of what has come to be known as the ‘quantum world’. Smith’s conception is based in traditional metaphysics, and seeks to destroy once and for all the stranglehold that Cartesian dualism has had over Western thought until the present day.

This distinction between the corporeal and physical world is examined in light of Mulla Sadra’s theory of perception, and similarly Sadra’s philosophy is evaluated in light of the distinction that Smith makes between the world of sense perception and the world accessible through measurement. Of particular importance is the role of the intermediate or imaginal world as a key to understanding both what Sadra has to say about perception as well as Smith’s own radical and philosophically powerful approach to deciphering such phenomena as non-locality and the so-called state vector collapse. The possibility of incorporating Smith’s views about physics into the Sadrian world-view is considered.

There is a fundamental difference between our common experience of the world and our encounter with that same world as seen through the lenses of scientific observation. For example, when one sees a red billiard ball, he sees a spherical red object. After subjecting this object to various sorts of measurement and observation, he is able to form a picture of its quantitative attributes. He is thus able to say that this thing is a rigid sphere with such and such a radius, of a certain density, possessing a determinable mass. The difference between these two billiard balls is that the first is directly perceptible by us, while the second is only accessible to us through the methods of scientific observation. In his book The Quantum Enigma, the mathematician and philosopher Wolfgang Smith discusses, among other things, our perception of objects (such as the billiard ball), and seeks to prove the error of Cartesian bifurcation1, which considers objects in the world to only possess quantitative measurable attributes, the qualities we associate with these objects being relegated to our own subjective world, or to the status of “secondary qualities”. Using Smith’s critique of the Cartesian dualism as a starting point, this paper will be a brief discussion of this realm of quantity as seen in the light of Mulla Sadra’s theory of perception.

* * *

The ball we perceive is what Smith calls the corporeal object, for which there exists a corresponding physical object. According to this terminology, the corporeal world is the world of perceived qualities, while the physical world is that of measured or measurable quantities. When we learn that the ball has a certain mass, we do not perceive this directly (although this too can be perceived in a certain qualitative manner) but do so by reading a corporeal pointer on a corporeal scale. We are able to perceive this reading, not by virtue of any quantitative attribute, but because, for example, the pointer and the numbers on the scale are black on a white background. All these are the qualities of the objects in question. It is thus pointless to speak of the primacy of measurable quantities, since we have no access to the results of our measurements without the perceivable qualities. To paraphrase Smith, no one, not even a scientist, has ever seen a rigid sphere of homogeneous density with radius x, and no one ever will. Ours is the world of the red ball, regardless of the measurements made on it by modern science. The corporeal world is the only door to the physical, and if one wishes to have any knowledge whatsoever of physical attributes, it must be accepted that we actually perceive the qualities of things, and that a real connection is made between the subject and the object. This explanation completely overturns the primacy of extension and refocuses our attention on quality, and in one stroke takes the self-proclaimed monopoly on knowledge of things “as they are” away from the scientist.

In Mulla Sadra’s theory of perception2, when man looks out upon the world, what he perceives falls into two categories: forms (suwar) and meanings (ma‘ani). The faculty that perceives forms is the sensus communis (al-hiss al-mushtarak), which functions to gather together the information brought in by the five external senses. Through this faculty we are able to perceive whole images or whole impressions. The forms perceived through the sensus communis are preserved in the imagination (al-khayal), also called the form-making-faculty (al-musawwirah).

As for meanings (ma’ani), they are perceived by the faculty of apprehension (al-wahm). The apprehension perceives meanings that are not the immediate content of sense perception. Sadra gives the example of the enmity a sheep perceives in a wolf, or the love one person perceives in another. For their part, these meanings are stored in the memory (al-hifz).

The faculty-of-disposal (al-mutasarrifah) is that power in man that takes apart and combines the forms and meanings it finds in the imagination and the memory. By virtue of this faculty one can inwardly put wings on a horse, or see the horse without its tail. “When the soul makes use of this faculty through the intermediation of the faculty of apprehension, it is called the imaginal-faculty (al-mutakhayyilah), and when it uses it through the intermediation of the intellectual-faculty it is called the faculty-of-thought (al-mufakkirah).”3 For Sadra, the faculty of apprehension is none other than “the essence of the intellectual-faculty being put into relation with a particular individual, its connection to him, and its governance for him. The intellectual-faculty connected to the imagination (al-khayal) is apprehension, just as its objects are the universal meanings put into relation with the forms of individual entities of the imagination.”4 The apprehension by definition deals with meanings in particular things, while the intellectual-faculty (al-‘aqilah) deals with meanings as such.5 As we shall see, the role of the faculty-of-disposal, which is polarized into the imaginal-faculty and the faculty-of-thought, must be made clear if one is to have a meaningful understanding of the practice of science.

* * *

We have already explained that the human observer, in conducting his scientific investigation, has access only to the corporeal world of qualities, the physical world being available to him only by virtue of its effects in the former. This act of perception itself is, in Sadrian epistemology, the domain of the five external senses and the sensus communis. When one speaks of perceptible qualities and measurable quantities in light of the distinction between the corporeal and the physical, one is saying in effect that sense perception (al-hiss) has access only to the former and not to the latter. It is through this act of sense perception that the human observer has any access whatsoever to the external world, to the world of the objects that he studies.

In order to understand how the human observer finds the physical attributes of an object, it is necessary to look to the faculty of apprehension. As we have noted before, according to Sadra the apprehension is that faculty in man which is able to perceive meaning in the forms it is presented with by the sensus communis or by the imagination. Enmity and love are not qualities that subsist in corporeal bodies qua corporeal bodies, but they nevertheless can be perceived in them and associated with them through the faculty of apprehension.

When one looks at our red billiard ball, one sees that it is spherical in shape. It is not, however, a sphere in the strictest sense, as it is not possible, by the very nature of the corporeal world, for a perfect sphere to be present within it. When we draw a triangle on paper, we are in reality not drawing a perfect triangle, no matter how fine our line or how precise our measurement of its angles. The line will always have some width, and upon inspection we find that this line is hardly smooth and regular. What we have drawn is a triangular shape, and yet we say that we in fact perceive a triangle, just as we can see a sphere in the billiard ball. In both cases, the perception of the geometric form is not a function of the faculty of sense, but rather of the faculty of apprehension. The sphere and the triangle belong to the domain of meanings, not of sensorially perceptible forms. This same principle holds true for any geometric shape in any corporeal object we observe. We perceive squares, cones, lines, and points in corporeal bodies by virtue of the presence of these forms in the intellect, which, when put into relation with an individual, becomes his faculty of apprehension.

Moving beyond merely the shapes of things, let us suppose that we throw this billiard ball in order to observe the effect. Repeating this act many times with multiple billiard balls, we find that the shapes of all the trajectories accord with the same type of mathematical formula. Standing at the proper vantage point, an observer can directly perceive the parabolic arc the billiard ball follows each time it is thrown. The parabola is perceived through the faulty of apprehension; one sees it in the corporeal world, but it is not a corporeal entity. Sadra mentions the similar example of a falling drop appearing as a line to an observer, which he uses as a proof for the existence of the sensus communis. The point he is trying to prove is that the faculty of sight as such only perceives a drop, and that the ability to see the falling drop as a whole is a function of the sensus communis. This must not be misconstrued as meaning that it is through the sensus communis that we perceive a line, that is, a perfect geometric line. It is the faculty of apprehension that perceives this meaning in the trajectory of the falling drop. This same reasoning holds for the parabolic arc traced out by the ball, although it is at a slightly higher level of mathematical complexity. Of course many more mathematical “meanings” can be derived from our study of the flying billiard balls, but regardless of the type of experiment we choose to perform, in each case we will discern a certain content within the corporeally perceived objects which is indicative of a mathematical idea, which is none other than the faculty of apprehension perceiving meanings in the sensorial forms it has access to through sense perception and through its storehouse, the imagination. It should be noted the ability to derive mathematical formalism from our inspection of the world and to derive still further mathematical meaning from our existing knowledge of mathematics is the domain, not of the apprehension, but of the faculty-of-thought, which as we know is the faculty-of-disposal coupled with the intellectual-faculty. It is by virtue of its being like “an intellect that has fallen from its elevation”6 that the apprehension perceives these universal mathematical ideas in the particular objects of the world.

The situation becomes more complicated when we begin to deal with physical entities that do not have any corporeal counterpart. That is to say, a rigid sphere of homogeneous density occupies the same part of space and time that we associate with the red billiard ball. Even if no one happens to perceive it at some given moment, nevertheless the corporeal counterpart to the physical ball can always be perceived under suitable conditions. The case is different for the entities studied in modern physics: the electron, the photon, fields, and every object with which quantum physics is concerned are physical objects that have no corporeal counterpart at all. No matter what the conditions, the electron is an entity that is never perceptible by any human observer; it is something one only has access to through the modus operandi of physics.

For Smith, this presents no special difficulty, since both the rigid sphere of homogenous density and the electron both belong to the physical world. In fact, all of the objects of the physical world are nothing but aggregates of the sub-microscopic entities dealt with in quantum physics. The crucial point to be remembered, however, is that the corporeal object is not an aggregate of particles. The corporeal object is the object of our perception; it is only the physical counterpart that can properly be viewed as an aggregate of protons, neutrons, electrons, etc.…

Now, it might appear on the face of it that in bringing to light the distinction between the corporeal and physical worlds in this way we have solved the problem of Cartesian bifurcation only to create another problem, namely that there now appear to be two objects that occupy the same region of space-time, each possessing qualities totally incommensurate with the other, yet somehow linked through our acts of perception. This almost sounds like a displaced bifurcation, but such is not at all the case, as shall become clear through considering what the physical world, from the perspective of the human observer, really amounts to.

Scientists rely on models when dealing with data that are not directly perceptible, or when observing the large-scale behavior of perceptible objects. Constructing a model necessarily entails giving some sort of form to quantitative data. There is, for example, the electron-cloud model of the atom, which is not a picture of an atom but rather a tool used to organize data involving the set of quantitative observations to which one assigns the name “atom”, a tool which is not purely mathematical but involves the use of images from our world of perception (in this case a cloud) in order to clothe these mathematical meanings with form.

Let us come back to the example of a sphere. It is impossible for us to picture or imagine a sphere in our minds in the absence of certain accidents, what Sadra refers to in this context as hay’at, meaning “frames” or “forms”. Try as we may, at the level of the imagination and apprehension we cannot picture a sphere without the aid, inwardly, of some sensible form drawn from the storehouse of our imagination. Indeed, we can perceive the intelligible sphericalness in this image we fashion, but that is not the same thing as that particular sphere itself, which falls short of the level of intelligibility precisely because it is one spherical object and not another; that it only possesses mental existence does not make it any less of a particular.7 When we imagine the trajectory of the thrown ball, apart from the ball itself and its surroundings, we never imagine a parabola as such. At best, we imagine something like a thin black line on a white background, but then we have already gone beyond the level of pure meaning and have coupled it with accidents.

Let us consider the case of light. As a physically measurable entity, light can be viewed as a wave, not because it is perceived as such, but because upon measurement it displays wave-like characteristics. When we say wave-like we mean that it resembles, in some basic way, the behavior of a perceptible, corporeal thing we call “wave”. However, light can also be viewed as being composed of particles, again not because it is perceived as particles but because upon measurement it displays particle-like characteristics, those of corporeal particles. Taken together these two points of view represent the well-known wave/particle duality of quantum physics, which is not limited to light, and which will serve well to illustrate the undervalued role of the imaginal faculty in the practice of physics.

When a physical entity corresponds easily to a sensible object, this process of “reifying” a mathematical meaning presents no great problem, as the corporeal counterparts are clearly in view. The case of light “waves” or light “particles” is very different. The mathematical meaning called a light wave has no corporeal referent, or perhaps it would be more accurate to say that there is no corporeal object whose corresponding physical object strictly speaking is a light wave or a light particle (a photon).

Physicists cannot, therefore, upon pain of absurdity, refer to photons as particles in the same way they refer to sand grains as particles. In the first case the scientist clothes a set of mathematical formulas with the form of a particle, which he draws from his imagination. This “particle” has the same ontological status as the black parabolic arc on a white background in our imagination; that is to say, it has no concrete external existence. Now, the sand grain is a particle that does possess external existence, and it is by virtue of the sand grain and other objects that rightfully bear the name “particle” that the scientist is able to go into his imagination and draw out an image that seems to fit best with his data. The fact that photons are not truly particles is brought out by the fact that light does not always behave like a stream of particles, but sometimes as a wave. When a physicist calls light a “wave”, he goes through the same process, drawing upon his imagination to clothe his mathematics with form. The truth of the matter is that from the very start light was never a particle nor a wave. Seen in this way, the paradox of the so-called wave-particle duality disappears, because we have never really left the world of mathematics.8

This process of fashioning imaginal models out of mathematical data is a legitimate and necessary practice of science. The problem is one of philosophy, not of scientific method. Only in a perspective where qualities are deemed secondary to the practice of “real” science can one lose sight of the fact that it is the corporeal world that possesses primacy, acting as our door to the physical, and moreover providing us with the raw material — consisting of the images such as “particle” and “wave” — that enables us to work more easily with the mathematical formalism we derive from our observation of the corporeal world.

* * *

By way of conclusion, it is necessary to point out that although the strictly mechanistic conception of the universe has been proven false beyond a shadow of a doubt by the discoveries of physics over the course of the last century, the prevailing scientific world-view, which has been almost completely adopted by the public at large, teaches that physicists are currently engaged in a pursuit to find the “fundamental building blocks of matter”. Using the term such as “building blocks” is problematic enough, as we have seen, but what of matter? The very notion of matter as this is understood in the modern context is part and parcel of the bifurcationist world-view, which sees a world of pure extension “out there”, which is somehow made of this elusive entity. The truth, however, is that no one really knows what matter refers to in the context of modern science. It denotes no measurable quantity, and is really nothing more than a symbol of the reign of quantity under which the modern world lives; “matter” is a philosophical question, not a scientific one.

Sadra tells us that we can only ever know form, and here we refer not to form as opposed to meaning but to form as opposed to matter; it is that by which a thing is what it is.9 The “matter” (al-maddah) of Sadrian metaphysics and indeed of pre-modern philosophy in the West is not the undefined “matter” spoken of in modern science; it is pure potential actualized through form. We only know the forms of things, never their matter. In this sense one can say that mathematics also consists of form, but form uncoupled from matter. For a hundred years all physicists have been doing is discovering mathematical form and structure; the search for matter can only be in vain, since for the scientist the only escape from the ocean of mathematical form beyond his direct perception is the dry land of our corporeal world, which consists, not of matter, but of forms belonging to the realm of quality.

Thus, at this level of reality, the corporeal world is the world of forms, but this does not mean that the physical world is the world of matter. When we say physical realm we are really talking about mathematical form in the corporeal world. The quantitative attributes of the physical realm are nothing more than the mathematical description of the behavior of corporeal objects. Thus our physical billiard ball, that so-called aggregate of particles, is nothing more than the sum-total of mathematical entities, arrived at much the same way one adds algebraic formulas together to arrive at a more inclusive formula.10

This metaphysical perspective puts man back at the center of his own world of perception, the only world, one might say from Sadra’s perspective, that God meant for him to live in and experience. It takes nothing away from the mathematics of physics but the confused ontology that has come to be associated with it. Instead, this mathematics is viewed as a description of the laws eternally present in the Divine Intellect which govern the corporeal realm. It becomes clear that one does not have to be a physicist to have a meaningful understanding of what the physicist does. Physicist and layman alike live in a world that is never reducible to numbers, a world that is impossible to leave except through the practice of bad philosophy.


1-Smith, Wolfgang, The Quantum Enigma, Peru, Illinois 1995. See also his Cosmos and Transcendence, chps. 1-2,as well as “Bell’s Theorem and the Perennial Ontology,” Sophia, summer 1997, pp. 19-38, and “The Extrapolated Universe,” Sophia (forthcoming). For a critical look at his work, see S. H. Nasr, “Perennial Ontology and Quantum Mechanics: A review essay of The Quantum Enigma,” Sophia (Summer 1997) pp. 135-157.

2-This paper deals mainly with the inward faculties of perception, or al-madarik al-batiniyyah. See Mulla Sadra, al-Shawahid al-rububiyyah fi‘l-manahij al-sulukiyyah (Mashhad 1981) pp. 193-195, al-Mabda‘ wa’l-ma‘ad (Tehran, 1976) pp. 242-252, al-Hikmat al-muta‘aliyah fi’l-asfar al-‘aqliyyat al-arba‘ah (Beirut 1981) v. 8. pp. 205-220. See also J.W. Morris, The Wisdom of the Throne (Princeton 1981) pp. 136-137, and F. Rahman, The Philosophy of Mulla Sadra (Albany, New York 1975) pp. 221-229

3-Al-Mabda’ wa’l-ma‘ad, p 249

4-Asfar, v. 8 pp. 216-217

5-see Asfar, v. 8, pp 216-218

6-see next note

7-In a section entitled “On the Kinds of Perception”, which clarifies this point and others, Sadra writes, “Know that there are four kinds of perception: sense perception, imagination, apprehension, and intellection. Sense perception is the perception of a thing existent in matter that is present with the perceived thing as frames (hay’at) particular to it (i.e. the perceived thing) and sensible with it, namely place, time, position, quality, quantity, and so forth. As regards some of these qualities, this thing is not separate form their like in external wujud, and no other thing shares them with it . . . That by which sense perception takes place and that which is essentially sensible and essentially present in the perceived thing is the form (surah) of that thing, not itself . . . It is necessary that what is realized in the sense be its form uncoupled (mutajarradah) from its matter, yet sense perception does not uncouple this form completely. Imagination, too, is the perception of this thing with the aforementioned ‘frames’, because the imagination does not imagine except that which it senses . . . Apprehension is the perception of a non-sensible meaning — indeed intelligible — which it however does not conceive universally, but in relation to a particular sensible, and for this reason no other thing shares it, owing to the fact that it is related to an individual thing. Intellection is the perception of a thing with respect to its quiddity and its logical definition, not with respect to any other thing, irrespective of whether this thing is considered by itself or with some other perceived quality . . .
There must needs be uncoupling in any perception; these perceptions are ranked in their uncouplement. The first has three conditions: the presence of matter to the organ of perception, the enclosement of the ‘frames’, and the perceived object’s being particular. The second (imagination) is free of the first condition, while the third (apprehension) is free of the first two. The fourth (intellection) is free of them all.
Know that the difference between perception through apprehension and that through intelleciton is not essential but is something external to it, and which consists in relating to it a particular and its non-existence. In reality perception is of three kinds, just as the worlds are three. It is as though apprehension is an intellect that has fallen from its elevation.” Asfar, v.3 pp 360-362

8-This is far from being the only apparent paradox in physics. The problems raised by the uncertainty principle and Bell’s Theorem, the latter which suggests simultaneous connections over great physical distances, are among them. For an introduction to modern physics as well as discussions of the philosophical implications of these discoveries, see The Quantum Enigma, pp 115-136, D. Bohm and B. Hiley, The Undivided Universe: An Ontological Interpretation of Quantum Theory (London 1993); G. Zukav, The Dancing Wu Li Masters, (Quill Marrow 1979); S. Hawking, A Brief History of Time (New York 1988); D. Mermin, “Is the Moon there When Nobody Looks? Reality and Quantum Theory,” and A. Shimony “Metaphysical Problems in the Foundations of Quantum Mechanics,” in The Philosophy of Science, Boyd, Gaspar, and Trout eds (Cambridge, MA 1991)

9-For an example of Sadra’s discussion regarding the perception of form, see Asfar, v. 3 pp 300-321, and also Risalat ittihad al-‘aql wa’l-ma‘qul in The Complete Philosophical Treatises of Mulla Sadra (Tehran 1999) esp. pp 75-76, and The Philosophy of Mulla Sadra, pp 221-225

10-“[T]he notion of macrosystem . . . belongs to the practical or pragmatic realm; it has to do with degrees of approximation and the feasibility of certain simplified models. In reality, however, every physical object constitutes a microsystem – by virtue of the fact that it is composed of atoms and fundamental particles. The microworld, thus, so far from constituting a subdomain, coincides actually with the physical universe in its totality . . .
It follows . . .that the so-called large-scale objects of physics are in reality just as strange as the electron or quark . . .” The Quantum Enigma, pp. 47-48


This article was published in Transcendent Philosophy Journal, London, Volume 1.  Number 2.  September 2000

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