Islamic humanism: from silence to extinction: a brief analysis of Abdulkarim Soroush's thesis of evolution and devolution of religious knowledge.

In a number of publications Abdulkarim Soroush has sought to propound and defend a thesis, 'the evolution and devolution of religious knowledge' (EDRK), according to which a religion (such as Islam) may be divine and unchanging, but our understanding of religion remains in a continuous flux and a totally human endeavor; he calls this view "Islamic Humanism". In this essay, I shall argue that the thesis of Islamic humanism collapses in the end into one of the various forms of religious nonrealism that have their origins in the works of some well-known contemporary Christian theologians.

Keywords: Islamic Humanism; Abdulkarim Soroush's evolution and devolution of religious knowledge; religious nonrealism; Islam and modernity; liberal Islam; religious thought.

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"It may well be that no one is injured when you fire your shotgun, but it would, at the very least, cause your neighbor's pigeons to shed some feathers."

Jalal Al-e-Ahmad

The Argument

The theoretical underpinnings of the thesis called "evolution and devolution of religious knowledge (EDRK) by Abdulkarim Soroush constitute an argument which appears in almost all of his works on this topic. (1) Because of its centrality, we may call it the Argument. In this section, I shall first expound and then criticize the Argument. Having challenged some of the cases that Soroush takes to support his thesis in the section that follows, I shall eventually show how it actually leads to nonrealism.

The Argument is, in fact, quite simple and can be thought of as having the following structure:

(a) Observation is theory-laden (p. 245). (premise)

(b) Meaning (interpretation) is theory-laden (p. 247). (from 'a')

(c) Presuppositions (background theories) are age-bound, and are, thus, in flux (p. 245). (premise)

EDRK: Religious knowledge (science of religion) is in continuous flux. (from 'b' and 'c')

It is rather difficult to make sense of the Argument, for as it turns out, it is both invalid and based on false premises. Nonetheless, we should try to be charitable when it comes to understanding its underlying motivation. Let us start with validity. The argument is manifestly invalid as there is no way that (b) can be derived from (a). Even assuming that "observation" is theory-laden, this can hardly result in any conclusion about "meaning". Observation, broadly understood, involves various forms of sensory contact with our environment. The resulting process, viz. perception, is what provides us with knowledge about the world. It is however a major issue in philosophy to understand how perception, as a type of cognitive process, works. At an abstract level, a cognitive process can be thought of as a function relating mental input to cognitive or behavioral output. For example, in the case of visual perception, input consists of stimulation of the retina which is then combined with various operations occurring in the visual cortex. The output would be the perception of whatever object that caused the stimulation. Accordingly, visual perception can be seen as a process that transforms sensory input into output that consists of a perception. It is nowadays (as in Cognitive Science) customary to try to understand cognitive processes by breaking them down into simpler sub-functions (as in Marr's computational theory of vision (2)) and finding out how the latter are accomplished. Another major question in the case of perception is whether the phenomenal character of an experience is detachable from its content and whether the latter has a conceptual or non-conceptual character.

Meaning, however, is a completely different animal. It is, generally speaking, what turns sounds or inscriptions into means of communication and understanding. Sometimes meaning is used in connection with what a speaker intends to communicate by a particular utterance (broadly understood). This is widely known as speaker's meaning, which may or may not coincide with the literal meaning of what is uttered (sentence meaning). The issues surrounding what constitutes sentence and speaker's meaning and how the two are related dominated philosophy of language for a good part of the twentieth century and continue to create quite a stir. From another angle, the problem of meaning has involved questions about the mechanism of reference and the semantics of various terms in natural languages. It would be preposterous to even try to give an outline of the debates in both the philosophy of perception and meaning here. However, trivial as the preceding remarks are, they must be sufficient to show that it is only by sleight of hand that someone could derive (b), 'Meaning is theory-laden' (whatever that means), from (a), 'Observation is theory-laden'.

Secondly, even granting validity, the Argument is still unsound as its two main premises are either simply false or, at best, highly controversial. Let us begin with (a). Soroush takes (a) to be "a fact of the history of science" (p. 245) claiming that "[t]he main and radical difference between positivist and post-positivist philosophy is the recognition of the fact ... that observation ... is theory-laden" (p.245). These claims however are just not true. To begin with, it is not at all clear that positivists would necessarily wish to reject the thesis that observation is theory-laden, as it all depends on how the thesis is to be understood. If it is only meant that observation is guided by theory in the sense that theories tell scientists what to observe, then no sane positivist would want to reject it. (I assume this is how Soroush understands (a), as it is very close to how Popper construes the thesis.) The thesis might however be intended as the claim that our theoretical assumptions directly bear on which observations one has to take seriously. But, understood thus, the thesis is in fact more a statement of the problem of theory testing (the Duhem problem) than the problem of whether observation can function as an objective basis for deciding between competing theories.

There is, however, a version of the thesis (a), propounded by Kuhn, that does mark a departure from empiricist philosophies of science. In Kuhn's view, observations themselves, viz., our perceptual experiences, not just the language used to describe them, are influenced by our theoretical beliefs. In other words, what we see is directly influenced by our theories. This version of the thesis, as just noted, does mark a radical departure from positivism, but equally breaks rank with some realist philosophies of science such as Popper's, as it undermines the claim that observation can provide an objective method of choosing between underdetermined theories. However, understood this way, it is far from clear that (a) is true. Anybody with a rudimentary grasp of philosophy knows that the Kuhnian version of the thesis that observation is theory-laden has been convincingly challenged by Jerry Fodor (who is no positivist), among others.

Fodor's challenge draws on his well-known modularity thesis according to which the mind is not a single, homogenous processing system, but consists instead of several task-specific, informationally encapsulated sub-systems that operate in relative independence from one another. There are three functionally distinct types of such subsystems: transducers, input and output systems, and central systems. Transducers lie at the interface between the mind and the world and are of input/output varieties. Input transducers (like the retina) take physical, non-symbolic input and produce symbols as output. The latter is, in turn, transformed into non-symbolic output (e.g., a neural firing) by output transducers. Then there are input and output systems that lie between transducers and the central system which produce representations of the world. These representations are then processed by the central system to produce beliefs about the external world. The central system is the domain of beliefs and other attitudes and is primarily concerned with belief fixation. Now, since input and output systems are modules, it follows that perceptual processing is unaffected by the theories that constitute our body of beliefs in the central system. The modularity thesis entails that there is an observation/theory distinction after all. Perceivers who differ in their background theories might nevertheless see the world the same way so long as those theories are inaccessible to their perceptual mechanisms. (3)

Let us now turn to premise (b), 'Meaning is theory-laden'. We saw that (b) is not logically derivable from (a), and that (a) is in any case controversial. Can (b) stand on its own? An initial problem is that it is very difficult to make sense of (b), not least because Soroush takes it to be true "in the same sense and exactly for the same reason ... [that (a) is true]" (p. 245). How could (b) really be thought of as a thesis about the nature of meaning when the background theories that allegedly confer (or unravel) meaning are themselves meaningful statements? What does it even mean to say that 'meaning is theory-laden'? The only way to turn (b) into a remotely plausible thesis is, I believe, to see it as a highly crude statement of the so-called 'conceptual role semantics' (CRS). The question about which CRS is intended to provide a response is what it is for a mental state (say, a belief) or a sign to have intentional or semantic content. In other words, we are required to say what it is in virtue of which a particular representation, say, a belief (sentence), has this rather than that content (meaning), or, alternatively, is about this rather than that object. What is at issue, then, is not just to find a semantic theory that ascribes to each meaningful sentence in a language (mental or public) a meaning but also provide an account of the nature of the ascribed meaning. (4)

CRS applied to the theory of content is actually functionalism, applied not to a particular type of mental state but to the contents of particular mental representations, e.g., the belief that p versus the belief that q. Accordingly, a belief state is said to have a particular content in virtue of its causal/functional roles. The appeal to causal/functional roles is intended to reflect the idea behind the so-called 'use' theory of meaning, according to which the meaning of an expression is determined by its use. It has, however, proved to be notoriously difficult to say what these roles are. There are currently two main views on this question, namely two-factor and single-factor theories. According to the two-factor theories there are two components or aspects to the meaning of an expression: a conceptual role component (entirely 'in the head' and usually adverted to in accounts of the so-called 'narrow content'), and an external component that connects (via a causal theory of reference or a theory of truth-conditions) the internal aspect to the world. Single-factor versions usually take functional roles to include relations to factors 'outside the head'.

So, applied to a basic perceptual belief (sentence) p, for example, 'There is a red book before me', CRS says that p has its particular content (meaning) in virtue of its causal roles that include causal relations to sensory experience (being appeared to redly), (inferential) relations to other mental states and to behavior. CRS is especially plausible as an account of the content of logical connectives where the relevant conceptual roles seem to consist exhaustively of inferential relations. CRS also seems credible if we take the view (with Kuhn) that theoretical terms in science ('mass', 'force', etc.) acquire their meaning only in conjunction with one another. The problem with putting this gloss on (b) is that it requires reading too much into the project of EDRK. Moreover, when (b), thus understood, is conjoined with (c) 'theories are in continuous flux', as the Argument demands, meaning is rendered entirely unstable and fleeting (as theories enter into inferential relations). The upshot is a CRS gone mad.

So much for the Argument, neither sound nor valid. This renders any further inquiry into the subject an extremely daunting task. The only way forward, I believe, is to trim our expectations and stop trying to inject philosophical rigor into Soroush's project. (5) Let us, then, see if we can make sense of (b) from a pre-theoretical vantage point and see where it takes us. Examples might help. Consider the following sentence (s): 'The night sky is lit by starlight'. What (b) seems to claim is that when trying to understand (s) we need to grasp the meaning of its constituent terms like 'star', 'light', 'sky', etc. In so doing, however, we inevitably bring our theories (presuppositions) about the referents of these terms to bear on their meaning. Now, given that these presuppositions have been continuously changing throughout the history, people have said and understood different things by uttering that very same sentence. Henceforth, I am going to fasten on this reading of (b) and, without further assessing its plausibility, try to see where it leads.

EDRK and Some Alleged Illustrations

Having understood (b) in the above manner, where is it supposed to take us? According to Soroush, when conjoined with (c), it leads to the following conclusions, among other things.

   Religion (revelation) is silent (p. 245).
   Revealed religion itself may be true and free from contradiction,
   but the science of religion is not necessarily so (p. 246).
   Religion is divine, but its interpretation is thoroughly human
   and this-wordly (p. 246).

These conclusions constitute the thesis of evolution and devolution of shari'ah (EDRK). Soroush further claims that the case of religion completely parallels that of nature: "The case of religion is no better than the case of nature. There also we are captives of our humanity. No human science is sacred, the science of religion being no exception" (p. 251). (This statement is not surprising. After all, his Argument began with a thesis about the nature of observation in science.) It is my contention that EDRK eventually collapses into varieties of religious nonrealism. Before embarking on this, however, I wish to examine certain illustrations that Soroush adduces in support of his thesis.

The first illustration concerns the case of tafsir bi'l-ra'y (or diraya) namely, the interpretation of the Qur'an according to one's wishes and views. The Islamic tradition explicitly warns people against such an undertaking. However, as Soroush notes, the exact meaning of this notion has been a constant source of controversy in Islamic scholarship. While rejecting the view that takes this notion as requiring an opinion-free interpretation of the Qur'an, he actually takes the controversy as supporting his own thesis. This is how he proposes to resolve the controversy within his own framework: "So how are we to understand the threatening warning about objective and opinion-free interpretation of the Qur'an? Isn't it the case that all interpretations are theory-laden? If so, then isn't it better to take the warning as meaning simply not to base our interpretations on unsubstantiated theories? Yes. That is all" (p. 247).

To see the irony behind the proposal, let us consider a concrete example. Suppose we wish to understand a verse in the Qur'an dealing with the immortality of the soul and the resurrection of the dead on the Day of Judgment. According to Soroush in understanding this verse we inevitably bring our philosophical (scientific) theories about, say, the nature of the mind, to bear on its content. But which philosophical theory should perform this function? The substantiated one, he would say. But that is a rather surprising suggestion coming from someone who believes that all theories (presuppositions) are age-bound and in continuous flux. It so happens, however, as a matter of fact, that, given any particular subject, say, the mind-body problem, there are usually a number of competing philosophical theories around each claiming to have its own share of plausibility. So the question still persists: which of these 'substantiated' theories should be called upon to do the job? Apart from being inconsistent, Soroush's proposal pushes the question only to a different level.

His other illustration concerns the distinction between muhkamat and mutashabihat in the Qur'an. The former category supposedly includes those verses that have unambiguous meaning whereas mutashabihat refer to the verses whose meanings are uncertain. Again, debates have raged over the exact criteria for making this distinction. It is not my intention to enter the debate here. Rather, I am at a loss to make sense of Soroush's gloss over the controversy: "All texts, especially revealed ones, should be expected to contain muhkamat as well as mutashabihat, whose existence is the clear cause of the expansion and contraction of the science of religion" (p. 249). Now, while the first part of the quoted sentence seems to acknowledge that the distinction is a genuine one, the second part takes this as underwriting the EDRK thesis. This is odd. For if there are muhkamat, this fact implies that certain parts of the Qur'an have a fixed meaning or interpretation not amenable to change. This is clearly at variance with the essential import of EDRK. I can conclude therefore that these cases are, by no means, instances of EDRK in action. Let us turn to the nonrealism charge.

EDRK and Varieties of Religious Nonrealism

Let us remind ourselves of the basic tenets of the EDRK thesis. It claims that since the interpretation of a (revealed) text (e.g., the Qur'an) is possible only through the medium of our presuppositions (background theories) and the latter are in continuous flux, so is our understanding of religion (or the science of religion): "since it is only through those propositions that one can hear the voice of revelation--hence the religion itself is silent" (p. 245). As noted earlier, Soroush thinks the cases of religion and nature are completely analogous in this respect. What is being suggested here is that there is a sharp cleavage between one reality, viz., religion as it is in itself and religion as it appears to us through our age-bound and ever changing presuppositions (the science of religion). In other words there is the religious reality, as a transcendent entity, that is just out there but is silent and cognitively inaccessible (henceforth, the Silent Real) and there is the human and this-wordly conceptual mirror, as it were, which reflects the Silent Real. We have no unmediated access to the Silent Real but can only hear its voice through our own constructive endeavors.

It is difficult not to notice shades of Kantianism here. For Kant there was the noumenal reality and the ways this reality appeared to us in our senses constituting the phenomenal world. The noumenal world is, however, epistemically inaccessible and beyond our conceptual reach, as Kant restricts our knowledge to the phenomenal world. Applied to religion, one may see the Kantian distinction as a distinction between the Silent Real and how it appears to us in our ever-changing interpretive apparatus. This is also roughly the position that John Hick occupies. He also holds that there is a noumenal reality which he calls The Real, and that there are various ways in which it appears to us in our experience.

   It is within the phenomenal or experienceable realm that
   language has developed and it is to this that it literally applies.
   Indeed the system of concepts embodied in human language
   has contributed reciprocally to the formation of the human
   perceived world. It is as much constructed as given--but our
   language can have no purchase on a postulated noumenal
   reality which is not even partly formed by human concepts. (6)

Notwithstanding Hick's richly detailed thesis, the structural similarities between his position and that of Soroush are striking. I suspect, in drawing the contours of EDRK, Soroush has borrowed heavily from Hick even if he tries to make it look as though the idea follows from something like the Argument. There is however a major difference between the two that is actually responsible for the eventual collapse of Soroush's position into full-blooded nonrealism. This stems from the role that the transcendent reality plays in their respective positions. The Real plays a substantial role in Hick's system by (apparently) allowing him to accommodate the problem of religious diversity. The idea seems to be that one can consider different religious traditions as constituting different ways in which we respond to The Real consequent to our religious experience; this is why Hick's position falls short of being a full-blooded religious nonrealism. But the Silent Real in Soroush's framework does no real work. It is just an entity out there, quiet and inaccessible, forever waiting to be heard and known only through human constructions. In the rest of this article, I am going to present two reasons as to why the Silent Real eventually becomes extinct. This will be followed by comparing this latter position with a well-known account of full-blooded nonrealism upheld by another contemporary 'Christian' thinker.

My first reason is pretty straightforward. Soroush himself comes to disown his silent religion! We may recall that he began by making a sharp distinction between religion itself (divine, perfect, etc.) and the science of religion (human, imperfect, etc.) which, he claimed, paralleled that between nature and the science of nature. However, later in his article, he repudiates the distinction in unambiguous terms.

   [T]he science of religion has been under continuous
   construction and reconstruction by various commentators and
   interpreters during its long history, and religion is nothing but
   the history of the science of the religion, of course. (p. 248,
   emphasis added)

I do not think this is merely a Freudian slip on Soroush's part. If an imperceptible 'silent' reality, as it is called in this picture, is forever inaccessible to us, what concern can it be of ours? How can something with which we can have no contact, something from which we are permanently sealed off, be expected to make any difference to our lives?

My second reason is that the above conclusion also follows from the other claims Soroush makes in the course of propounding his thesis. Talking about interpreting religion in the light of one's presuppositions, he adds the following caveat:

   It should be obvious by now that it is not enough for an
   interpreter to give simply a consistent interpretation of a whole
   text; interpretation must also be consistent with the received
   wisdom of the age. (p. 246, emphasis added)

The above remark is clearly intended to be a constraint on allowable interpretations (of revealed texts). Internal consistency is not enough. The interpretation must also be consistent with the wisdom of the age (which includes philosophy, science, etc.). To get a better grip on this remark, suppose one comes to an understanding of a particular verse in the Qur'an (which could be about as diverse subjects as the nature of the world, man, morals and the like). To be admissible, this interpretation must also cohere with our current philosophical and scientific theories about the subject in question. If it turns out to be incompatible with those theories it will have to be rejected. (Actually, the above caveat may be unnecessary, for if, according to Soroush, we can only interpret a text in the light of our presuppositions, the required coherence is already guaranteed. But I am not going to press this point any further.)

But now, one may wonder whether this methodology really leaves any room for religion to function as an independent source of knowledge besides the customary ones. For if it is the received wisdom of the age that is the final arbiter in deciding which interpretation is admissible, why not rely on that wisdom in the first place? Why bother to see what, say, Islam has to offer on a particular subject, if what it purportedly says is admissible only if it is consistent with the wisdom of the age? We might as well cut out the detour through religion and rely simply on our sciences of the day to begin with. What good is religion if it is to ride on the back of human sciences for its legitimacy? Thus understood, religion is no more than a third wheel that, being redundant, can be easily dispensed with. Incidentally, Soroush's claims notwithstanding, the analogy between religion and nature also breaks down. For, unlike religion, nature is not silent. It is, indeed, the final arbiter in deciding which of our scientific theories are admissible. Our theories are either confirmed or refuted in the process of testing. This is the idea behind the old saying that man proposes and nature disposes.

The upshot of the preceding remarks is that Soroush's own views render religion redundant. At best, it might be expected to function as a motivational or moral factor in influencing our lives. This would be a religion without the supernatural, viz., full-blooded religious nonrealism. In fact, Soroush makes certain allusions in that direction. He describes his stance as a "subtle instance of the naturalization of the supernatural, or if you like, the manifestation of the supernatural as and in the natural" (p. 251):

   To capture the true intention of the Revelator is an ideal
   towards which all of us approach collectively, but in the end we
   may discover that the true intention of the Revelator was
   nothing but the collective endeavor of mankind itself.

In short, he claims to advocate, what he calls, 'Islamic humanism': "I opt for the humanization of religion" (p. 250). It is, once again, difficult not to notice the echoes of the views of another 'Christian' thinker in Soroush's final and considered position, viz., Don Cupitt, who advocates full-blooded religious nonrealism and labels his position 'Christian humanism'. While still practicing Christianity for spiritual and moral reasons, Cupitt rejects objective theism and the "realist ontology, the notion that there is something out there prior to and independent of our language and theories, and against which they can be checked." (7)

   The only language we can know is wholly human ... So we
   should see religious language in terms of the part it can play in
   our lives, rather than see it in a mythological way as conjuring
   up a picture of a second world. For us there is only one world
   and it is this world, the manifest world, the world of language,
   the world of everyday life, of politics and economics. (8)

Despite the preceding arguments and textual evidence, I am still disinclined to see Soroush as advocating full-blooded religious nonrealism in the manner of Cupitt. But, then, I find myself at a loss to understand the logic behind Soroush's approvingly quoting Cupitt's laudatory comments on his position on his website. Here is Cupitt reacting to precisely the same passages that we have discussed in the last few paragraphs.

   [E]ducated Muslims debate about Islam and scientific
   knowledge. Conservatives argue for the Islamization of
   knowledge ... Liberals argue for the Scientisation of Islam ...
   Soroush here seeks a third way--the humanization of religion.
   Disarming criticism, he concedes that God and Revelation may
   in themselves be eternal, absolute, unchanging. But they are
   silent until religion exists among human beings, and when that
   happens religion is relativised, questioned, and reformulated.
   There is no text with only one interpretation, no musical score
   played in exactly the same way by all musicians. It is brave of
   Soroush to put forward such ideas in an Islamic setting. Can
   Islam become a developing and 'humanised' religion of hope
   and aspiration, rather than a religion of dogmatic certainties?
   The answer to that question will matter a lot to us all. And the
   same question can be asked of Christianity, as well. (9)

Coda

Those familiar with Soroush's political influence in contemporary Iran might be surprised that something as tenuous as the Argument or the subsequent inconsistent remarks of his could have made any political impact. They may feel that something must be amiss in the picture I have painted of his work in this review. But this essay was not intended to be an exercise in understanding the socio-political kinematics of ideas, and, in any case, having political impact can hardly be a reliable indicator of the truth of pertinent thoughts or ideas--as amply evidenced by the recent political upheavals of our time. An analogy might help. One can shatter a window by raising the pitch of one's voice to a high enough level (Pavarotti might be able to do that). But, then, when that happens, it would happen regardless of whether one was reciting from Rumi or was talking gibberish. (10)

I began this essay with a quotation from Al-e-Ahmad. This was not meant to be a call to self-censorship or suppressing one's thoughts. He was, I think, merely demanding that, when enunciating an idea, one should do one's best to exercise sufficient care by trying to fulfill the relevant intellectual obligations. For it is only then that one can be said to be an epistemically responsible agent. Epistimically foregoing responsibility by propounding half-baked, confused and poorly-argued thoughts can only lead to sensational sloganism which is actually what has plagued recent intellectual movements in the Muslim world. Al-e-Ahmad's admonishment, one may suppose, assumes more urgency when it is religion that one is tampering with. Perhaps, however, such worries are misplaced, at least in the case of religion, for we have it on very good authority that Indeed We have sent down the Reminder, and indeed We will preserve it. (11)

(1.) The corpus of Soroush's work on this topic in Persian is huge, though often repetitive. Moreover, the main structure of his argumentation is often obscured by digressions and embellishments, such as quotations from Rumi, Sa di and other great Persian poets and writers. This makes an analysis of his theses extremely difficult. In this review, however, I will be focusing on one of his English articles wherein all such decorations have been set aside, thanks to the (ruthless) necessities of translation. All page references in this essay are to the following source: Soroush, A., "The Evolution and Devolution of Religious Knowledge" in Kurzman, C. (ed.) Liberal Islam (Oxford: Oxford University Press, 1998).

(2.) Marr, D., Vision (San Francisco: W. H. Freeman, 1982).

(3.) See, for example, Fodor, J., "Observation Reconsidered" in A Theory of Content and Other Essays (Cambridge: MIT Press, 1984).

(4.) See, for example, Block, N., "Advertisement for a Semantic for Psychology" in Midwest Studies in Philosophy X, (1986), 615-78.

(5.) I am skirting around many remarks in Soroush's paper as they are hardly intelligible. Some samples follow.

(i) "In order to justify a statement rationally, one has to rationalize it first." (p. 247)

(ii) "Only a conceptually philosophical religion (or, meticulously put, a philosophical comprehension of a religious text) can be reconciled with philosophy." (p. 247)

(iii) "As an instance of a non-linguistic presupposition, I may point to the problems one expects religion to solve--in brief the question of expectations." (p. 249)

(6.) Hick, J., An Interpretation of Religion (New Haven: Yale University Press 1989), 350.

(7.) Cupitt, D., What is a Story (London: SCM Press, 1991), 82.

(8.) Cupitt, D., "Anti-Realist Faith" in Helm, P., Faith and Reason (Oxford: Oxford University Press, 1999), 303.

(9.) See http://www.drsoroush.com/English/On_drsoroush/E-CMO-0020300-1.html accessed on March 24, 2005.

(10.) One should not construe the general thrust of this review as being antipathetic with regard to the motives behind some of the reformist projects in Islam. The idea was merely to illustrate, as in the case of Soroush's project of EDRK, the kind of reform one may end up with, if one were to follow them to their logical conclusion.

(11.) al-Isra: 9.

Hamid Vahid, School for Fundamental Sciences, P.O. Box 19395-5746, Tehran, Iran. Email: [e-mail]