This paper presents an edition of al-Hasan ibn al-asan ibn al-Haytham's (d. 1040) treatise, Qawl fi samt al-qibla bi-al-isd al-K (15th century), some four centuries after the introduction of this method by Ibn al-Haytham. The present treatise represents an important juncture in the history of the development of mathematics of the qibla, and sheds more light on the contributions of one of the most important scientists of medieval Islam.
This paper studies the first metaphysical theory in Arabic philosophy, that of al-Kindi, as found in "On First Philosophy" and other of his works. Placing these works against the background of translations produced in al-Kindi's circle (the "Theology of Aristotle," which is the Arabic version of Plotinus, and the "Liber de Causis," the Arabic version of Proclus' "Elements of Theology"), it argues that al-Kindi has two conceptions of being: "simple" being, which excludes predication and derives from Neoplatonism, and "complex" being, (...) which is based on Aristotle's notion of substance. At the end of the paper the "simple" notion of being is seen to anticipate in some respects Avicenna's distinction between existence and essence. (shrink)
Al-Fbb al-f, is apparently the first person to maintain that existence, in one of its senses, is a second-order concept [mal th]. As he interprets Metaphysics d] has two meanings, second-order being as truth'' (including existence as well as propositional truth), and first-order being as divided into the categories.'' The paronymous form of the Arabic word mawjd] distinct from their essences: for al-Kindd of all things. Against this, al-Fburr thinks that Greek more appropriately expressed many such concepts, including being, by (...) particles rather than nouns or verbs; he takes Metaphysics r's title can mean both Book of Particles'' and Aristotle's Metaphysics.''. (shrink)
This article proposes a reconstitution of the philosophical tenor of al-Fb al-Mawdayyira). It is shown that this work is not only a response to book VI of John Philoponus' Contra Aristotelem, but that its real issues can only be grasped in the context of the author's metaphysical system. Although, for al-Fbī, genuine demonstrations proceed from the cause to the caused, thus following the order of being, it will be explained how he also admits a strictly physical proof of the simple (...) fact, independently of its cause, and that the physical demonstration of the eternity of the world pertains to this type of proof. This physical proof is specifically directed against the Kindian doctrine of creation. (shrink)
al-Fārābi was well aware that ecumenism can easily convert to tyranny if a certain city–state attempts to impose its laws outside its territory. State legislation depends on specific cultural and historical factors which deprives it from being universal because culture and history could not unite different nations in an ecumenical state. Legislation has to be built on universal premises, e.g. on philosophy, so as to serve the needs of a global state. Philosophy is the bond which unites humans and communities, (...) while religion and legislation are disruptive factors. Despite the fact that in our days there are different philosophies, philosophy encourages dialogue, not hatred. As a result, al-Fārābi was right when he founded his ecumenical state on philosophy. Consequently, philosophers ought to persuade the citizens through rational arguments, dialectic, symbols and religion so as to accept the existence of an ecumenical state. The goal of this state is the supreme good, understood as the theoretical living. Al-Fārābi’s ecumenism is a means for the perfection of human beings and societies and not simply for the augmentation of wealth, as it is seen today. Al-Fārābi dreams of an anthropocentric ecumenical state. I support that this should be the form of modern ecumenism. While modern scholars have strong objections to the governing of philosophers, we should agree that philosophy is the appropriate universal language. The persistence on power and other divisive factors, such as religion or tradition, is doomed to fail. (shrink)
Mythological language is sometimes understood as a way of representing, by concrete imagery, more abstract notions. In this paper, we will pose some metaphysical questions about the possibility of such a representation. These questions will serve to motivate a brief tour of Mishkāt al-Anwār (Niche of Lights)—Abu Hamid al-Ghazali’s commentary on the famous ayat al-nur (“verse of light”) of the Qur’an—wherein is discussed, among other things, how symbolic imagery is possible, and “the respect in which the spirits of the meanings (...) are specified within the frames of the similitudes.”. (shrink)
Tomasello et al.'s two prerequisites, we argue, are not sufficient to explain the emergence of Joint Collaboration. An adequate account must include the human-specific capacity to communicate relevant information (that may have initially evolved to ensure efficient cultural learning). This, together with understanding intentional actions, does provide sufficient preconditions for Joint Collaboration without the need to postulate a primary human motive to share others' psychological states.
The method of doubt has been used in philosophy and theology by both philosophers and theologians, among them al-Ghazālī. Al-Ghazālī’s method conveys the process of how he was cured of his epistemological and existential crisis. This study analyzes each phase of the process in terms of epistemology and logic; it explains the problems and how they appeared to al-Ghazālī.
Among the many logical works by Ab? Nasr Muhammad al-F?r?b? (870?950), there are two commentaries on particular books or points of Aristotle's Topics, whose original Arabic text has been apparently lost. A number of quotations of one or both of them, translated into Hebrew, has been recently found in a philosophical anthology by a fourteenth-century Provençal Jewish scholar, Todros Todrosi. In this article, a detailed list of these quotations is given, and a tentative short examination of the contents of each (...) of them is offered. (shrink)
The Hippocratic Aphorisms is a well-known treatise which was very popular throughout the ages. This paper studies the Arabic translation of [Hdotu]unayn ibn Ishaq, the renowned Arab translator, of the first book of the Aphorisms as well as the commentary of Ibn al-Nafis, the thirteenth-century Arab doctor, on the same book. This study highlights the difficulties that occasionally confronted the Arab commentator while commenting. The obscurity of a few Hippocratic sentences as well as [Hdotu]unayn's interpretation and alteration in meaning were (...) probable sources for those difficulties. Ibn al-Nafis, however, was unaware of the role played by [Hdotu]unayn in shaping the Arabic text. Ibn al-Nafis reflected a deep trust in the Arabic text to the degree of commenting on every single word. He used both his intellect and his knowledge of other commentaries to solve those problematic phrases. He did not exhibit an interest in philological matters to help explain the text. His commentaries reflect his respect and appreciation for both Hippocrates and Galen, the latter of whom exercised some influence on [Hdotu]unayn and Ibn al-Nafis in their understanding of the work. Nonetheless both [Hdotu]unayn and Ibn al-Nafis showed traces of independence from Galen's influence. (shrink)
The mathematician al-Mahani (9th century AD) is the author of one of the first commentaries on the fifth Book of Euclid's Elements which have been handed down to us. In this commentary, al-Mahani intends to justify Definitions V. 5 and V. 7 of the Elements, which deal with the identity of ratios and with greater ratio, by starting from an anthyphairetic conception of ratio, and by proving the equivalence of the Euclidean and the anthyphairetic points of view. We will try (...) in this paper to describe in detail the content of al-Mahani's commentary, basing ourselves on a thorough examination of most of the extant manuscripts of the Arabic text. The reader will also find in the appendices a mathematical commentary, an English translation, and a critical edition of al-Mahani's commentary. (shrink)
Aristotle's Definition of a Science of Being qua Being Selected Bibliography on the Meanings of Being in Aristotle The Place of Metaphysics in the Ancient Divisions of Philosophy The Peripatos after Aristotle's and the Origin of the Corpus Aristotelicum Bibliography on the Ancient Catalogues of Aristotle and the Corpus Aristotelicum Ancient Catalogues of Aristotle's Works: English studies Diogenes Laërtius, Lives, V 22-27 Hesychius of Miletus and Ptolemy al-Garib Listes Anciennes des Ouvrages d'Aristote: études en français Diogène Laërce, Vies V, 22-27 (...) Hésychius de Milet et Ptolémée el-Garib The Oblivion of Being After Aristotle: Theophrastus' Metaphysics.. (shrink)
This paper investigates the objections that were raised by the philosopher ‘Abd al-La[tdotu ]if al-Baghdadi (d. ca. 1231 CE) against al-[Hdotu ]asan ibn al-Haytham’s (Alhazen; d. after 1041 CE) geometrisation of place. In this line of enquiry, I contrast the philosophical propositions that were advanced by al-Baghdadi in his tract: Fi al-Radd ‘ala Ibn al-Haytham fi al-makan (A refutation of Ibn al-Haytham’s place), with the geometrical demonstrations that Ibn al-Haytham presented in his groundbreaking treatise: Qawl fi al-Makan (Discourse on place). (...) In examining the particulars of al-Baghdadi’s fragile defence of Aristotle’s definition of topos as delineated in Book IV of the Physics, which was rejected on mathematical grounds by Ibn al-Haytham, a special attention is also given to highlighting the systemic distinctions between the entities that are studied within the speculative physical doctrines of common sense and immediate experience, and the postulated ‘objects’ of scientific and mathematical research. (Published Online February 12 2007) Footnotes1 An earlier concise version of this paper was presented on 18 February 2006 in Florence, under the title: ‘The physical or the mathematical? interrogating al-Baghdadi's critique of Ibn al-Haytham's geometrisation of place’, as part of the Colloque de la Société Internationale d'Histoire des Sciences et des Philosophies Arabes et Islamiques (Circulation des savoirs autour de la Méditerranée, IXe–XVIe siècles), which was held in association with the University of Florence. This text will be published as part of the Proceedings of the Colloquium (Les Actes du Colloque), under the editorship of Graziella Federici Vescovini (Florence). (shrink)
For Averroes, celestial circulation is evidence of a divinely mandated rational universe. This paper follows Averroes’ account on cosmic contact between the eternal and the temporal, in Tahafūt al-tahafūt contra al-Ghazālī. It argues that the polemical perspective of the Tahafūt al-tahafūt frames Averroes’ appeal to Aristotle’s account of cosmic motion. Consequently, Averroes’ exceptional account of the universe contrasts Aristotle’s exemplary account of the mutual participation of intellect and nature. Their accounts of celestial circulation implicate the status of human nature conditioned (...) by cosmic nature. As such, the possibility of human freedom rests on the nature of causality between divine intellect and cosmic manifestation. The convergence and divergence of Aristotle and Averroes regarding celestial circulation reveals Averroes’ politics that guide a rational argument for a strong cosmic causal connection between the unmoved mover and the universe, against al-Ghazālī’s rationally inaccessible divine will. (shrink)
Crupi et al. () propose a generalization of Bayesian conﬁrmation theory that they claim to adequately deal with conﬁrmation by uncertain evidence. Consider a series of points of time t0, . . . , ti, . . . , tn such that the agent’s subjective probability for an atomic proposition E changes from Pr0(E) at t0 to . . . to Pri(E) at ti to . . . to Prn(E) at tn. It is understood that the agent’s subjective probabilities change (...) for E and no logically stronger proposition, and that the agent updates her subjective probabilities by Jeffrey conditionalization. For this speciﬁc scenario the authors propose to take the difference between Pr0(H) and Pri(H) as the degree to which E conﬁrms H for the agent at time ti (relative to time t0), C0,i(H, E). This proposal is claimed to be adequate, because.. (shrink)
Abstract Ab? Yazid al?Bist?mi (d. 874 AD) was a renowned early s?fi who exerted a tremendous influence upon the doctrinal formulation of the sufism of medieval times. A highly controversial figure, he is venerated by some as a top?ranking saint and s?fi, condemned by others as a notorious heretic, and there are still others who suspend judgement on him. More than 200 years after him al?Ghaz?li (1058?1111 AD) flourished as the greatest s?fi of all times; he examined and evaluated the (...) teachings of his s?fi predecessors including Ab? Yazid. To determine his evaluation of Ab? Yazid and his opinion on the related, well?known concept of man's union with God at the highest peak of spirituality is the main aim of this paper. To achieve this aim al?Ghaz?li's citations from Ab? Yazid's teachings on many basic doctrines of sufism, together with his explicit comments on them, are analysed in the second section of the paper, and he is found to have evaluated these teachings as of a very high grade and to have extolled Ab? Yazid as a s?fi of the highest rank. The third section studies al?Ghaz?li's opinion on the most important aspect of Ab? Yazid's teachings, i.e. his shatah?t or ecstatic utterances apparently expressive of union, fusion and divine indwelling. This began with a consideration of al?Ghaz?li's definition of two kinds of shath and his condemnation of them on the grounds of their harmful consequences. In connection with a study of his condemnation of the shatah?t of Ab? Yazid and al?Hall?j an investigation is made into his opinion on union and fusion. It is found that throughout his s?fi life he condemned them as false concepts. However Ab? Yazid's shatah?t, which apparently mean union, fusion, etc. are interpreted in an orthodox manner, and he is adjudged an elect of the elect, a gnostic who reached the level of reality of realities, a perfect s?fi who attained to God. All the above findings are based on al?Ghaz?li's explicit comments on Ab? Yazid. The fourth section of the paper deals with his implicit, indirect comments which also prove his appreciation of, and indebtedness to, Ab? Yazid in respect of several central concepts of sufism. (shrink)
This paper examines al-F?r?b?'s logical thought within its Arabico-Islamic historical background and attempts to conceptualize what this background contributes to his logic. After a brief exposition of al-F?r?b?'s main problems and goals, I shall attempt to reformulate the formal structure of Arabic linguistics (AL) in terms of the ontological and formal characteristics that Arabic logic is built upon. Having discussed the competence of al-F?r?b? in the history of AL, I will further propose three interrelated theses about al-F?r?b?'s logic, in terms (...) of which I will attempt to redefine it: the logico-linguistic conception, the project of logicization, and nuclear logic. The final question that will arise is how Aristotle's logic could be built upon AL, which has a nature contrary to logic. The present paper also contributes to examining our traditional research habits in Arabic studies. (shrink)
What is the function of logic in al-Kind's theory of categories as it was presented in his epistle On the Number of Aristotle's Books (F treats the Categories as a logical book, but in a manner different from that of the classical Aristotelian tradition. He ascribes a special status to the categories Quantity (kammiyya) and Quality (kayfiyya), whereas the rest of the categories are thought to be no more than different combinations of these two categories with the category Substance. The (...) discussion will pay special attention to the function of the categories of Quantity and Quality as mediators between logic and mathematics. (shrink)
After his refutation of the doubts concerning Proposition I.7 (in the Book of solving doubts), Ibn al-Haytham mentions three possible ways in which circles may intersect, submitting them to the following “intuitive” argument: one part of one of the two circles is situated inside of the other circle, and its other part is situated outside of it. One is therefore tempted to believe that the commentator accepts the principle of continuity in the case of circles, since his argument has the (...) following meaning: if a circle is divisible into two parts (or, again, passes through two points), one of which (or one of the two points) is situated inside the other circle, and the other outside of it, then the two circles cut one another. The author of this article proposes to establish the limits of this belief, on the basis of the following reflections: 1). It will be noted first of all that what could be called the ‘principle of the intersection of circles’ does not constitute ipso facto a principle in the mind of Ibn al-Haytham: no allusion is made to it in the commentary on Proposition I.1, among others. 2) It will be established later on that if one accepts (according to the explanation of Ibn al-Haytham in his Commentary on the premisses) that a line is the result of the movement of a point, the principle of continuity should be considered by him as something which is obvious by itself, without being stated. This conclusion will be based on an analysis of the notion of continuity in its classical meaning, and on Ibn al-Haytham’s commentary on Proposition X.1. 3) On the other hand, we should note the presence of a ‘sketch’ of topological language, which Ibn al-Haytham develops for the notion of a circle (particularly in the Commentary): one could say in this context that his reflection constitutes an important, if not principal, stage in the process which was to lead to the explicit formulation of the principle of continuity. Footnotes1 Je voudrais remercier chaleureusement Monsieur R. Rashed d'avoir bien voulu lire la première version de cet article, m'envoyer certaines de ses publications et me communiquer ses suggestions dont j'ai essayé de tirer le plus grand profit dans la révision que voici. Toutes les insuffisances qui s'y trouvent ne peuvent que m'être imputées. (shrink)
In this article the author analyzes a fifteenth-century Arabic reform of the Ptolemaic model for Mercury. The author of the reform was the Central Asian Al al-D (d. 1474 A.D.) who, in his youth, had been instructed in the mathematical sciences by none other than the famous Central Asian monarch Ulugh Beg (1394 has been yet identified to have produced a theoretical text devoted to the criticism, let alone the reform, of the Ptolemaic mathematical planetary models. The present article on (...) Qushji's reform of the Ptolemaic model for Mercury includes a critical first edition of Qushji's Arabic text, an English translation, and a historical and technical commentary. (shrink)
The problem of the Qibla was one of the central issues in the scientific culture of Medieval Islam, and to solve it properly, one needed mathematics and observation. The mathematics consisted of two parts: plane trigonometry (to construct the trigonometric tables) and spherical trigonometry (as the problem belongs to spherical astronomy). Observation and its instruments were needed to find the geographical coordinates of Mecca and the given location; these coordinates (latitude, longitude) will be the input data in the formulas of (...) the Qibla. In his Almagest, Abmodern al-Waf's mathematical methods and the Qibla determinations, supplemented with many important original Arabic texts with translation and commentary. (shrink)
The author examines the relationship between mathematics and philosophy in the works of al-Kind on the approximation of 's knowledge of mathematics, and on the history of the transmission of The Measurement of the Circle of Archimedes. The author shows that al-Kind M, and that it was one of the sources of the Florence Versions, the Latin commentary on the same proposition.
Ibn al-Fa's Kitmin, the Book of the Delight of the Believer preserves, in the first part, in at least three of its 100 philosophical and theological problems, passages from the hitherto lost Arabic version of Philoponus' De Aeternitate mundi contra Proclum. All quotations are taken from the refutation of the first proof, one of them from the beginning which is also lost in Greek. For this latter passage a parallel is found in al-Isfiz who draws on the same Philoponus source (...) in his Kit Masil al-umhiyya (Book on Metaphysical Questions). A comparison of the other passages to the extant Greek text suggests that al-Ank's overall accurate use of sources can be gained from his quotations of the extant Arabic versions of the De Anima-paraphrase, Nemesius' De Natura hominis and b. Rabban al-'s Firdaws al-ḥikma (Paradise of Wisdom). (shrink)
Transmission electron microscopy (TEM) was used to study the precipitation in an 8090 (Al?2.7Li?1.4Cu?1Mg?0.11Zr (wt %)) alloy. TEM diffraction patterns revealed reflections from the orthorhombic S?/S (Al2CuMg) phase in addition to those of the fcc α matrix, the coherent and ordered δ?(Al3Li) phase of L12 structure and the hexagonal T1 (Al2CuLi) phase. The reflections from the T1 phase were identified and indexed using literature results. Concerning the S?/S phase, a theoretical study, based on its orientation relationships with α, allowed the (...) construction of transformation matrixes between planes and directions of their reciprocal lattices. The calculation shows that 12 different S?/S systems can diffract on a given α phase selected area diffraction (SAD) pattern. Theoretically, two diagrams ( and ) are considered, on which the S?/S reflections are indexed. The results obtained for the theoretical patterns are in good agreement with those observed experimentally. (shrink)
The distribution of variants and three-dimensional (3D) configurations of the heterogeneously formed S (Al2CuMg) precipitates at dislocations, grain boundaries and the Al20Cu2Mn3 dispersoid/Al interfaces were studied in this research. By means of high resolution transmission electron microscopy, we systematically investigated the orientation relationships (ORs) between these heterogeneously formed S precipitates and the Al matrix, and further unraveled that the preferred orientation of S variants at grain boundaries and at dispersoid/Al interfaces are respectively associated with the OR between the precipitate habit (...) plane and the grain boundary plane, and the OR between the precipitate habit plane and the interface plane. The inherent characteristic of the crystal structure of the S phase, i.e. the symmetry of the pentagonal subunit, was considered to be the fundamental factor determining the preference of the variant pair. By using high angle annular dark field scanning transmission electron microscopy tomography, we successively obtained the 3D reconstruction of the S precipitates at these defects. Both the morphology of an individual S precipitate and the overall configuration of the S precipitates nucleated at these defects can be clearly observed without misunderstandings induced by the overlap and projection effects of the conventional two-dimensional methods. (shrink)
Summary This paper is concerned with a mechanical calendar described by the great scientist al-B?r?n?, who died in 440/1048. The description occurs in a book devoted to the construction of various types of astrolabe and related instruments. The Arabic text presented in this paper was prepared from three manuscripts. This is preceded by a brief introduction which gives a sketch of the life and works of al-B?r?n? together with information about the provenance and contents of the three manuscripts. The text (...) is followed by an English translation and the paper concludes with a technical commentary which discusses the construction and operation of the instrument. This commentary is accompanied by explanatory drawings reconstructed from al-B?r?n?'s descriptions. Photographs from the illustrations in the manuscripts are also provided. (shrink)
Abu Hamid al Ghazali, one of the most famous intellectuals in the history of Islam, developed a definition of Unbelief (kufr) to serve as the basis for determining who, in theological terms, should be considered a Muslim and who should not. Jackson's annotated translation is preceded by an introduction that reconstructs the historical and theoretical context of the Faysal and discusses its relevance for contemporary thought and practice.
Al-Fbsifa. In part, this is because the commentary was in some respects a scandal, and scholars accordingly believe it may hold the key to resolving present-day disagreements on how to interpret al-Fbr's most shocking or scandalous statement is that preserved by the Hispano-Muslim philosophers Ibn Bufayl, and Ibn Rushd. According to them al-Fb generally considered the highest goal of human existence by the philosophers r's commentary is still lost, I have discovered two quotations of it in Hebrew manuscripts. As I (...) will argue in this paper, these newly-discovered quotations can shed light on the mysteries concerning al-Fbī's commentary. (shrink)
'Abd Allâh Ibn al-Muqaffa' (724-759) is known mainly as the translator of the Kalila wa-Dimna, a collection of tales, that he translated from Pahlavi (Middle Persian) into Arabic. Ibn al-Muqaffa’ was of Iranian ancestry and was proud of the Sassanian legacy. He was self-confident of the rational primacy of the Zoroastrian religion over the Arabic culture that at that time consisted of the Koran and poetry. In the article I point to the rational values found in the comments of Ibn (...) al-Muqaffaÿ as related to the Zoroastrian legacy. (shrink)
This volume contains the most extensive exposition of Latin American philosophy to date. I know of no other comparable anthology on the subject in any language. The width of its scope is quite impressive. At least for this reason, and whatever its shortcomings might be (to some of them I’ll come to speak below), it is a welcome collective work.
This paper sets out to chart the fortunes of one of the most significant moral propositions in Mu'tazilite moral theory — namely, that it is evil to lie, and it is evil irrespective of the consequences of so doing. The reasons which promote this principle to significance relate to the broader context of Mu'tazilite theological orientation, which aims to vindicate God's justice through demonstrating that moral value does not derive from revelation. Yet this principle suffers the difficulties which commonly afflict (...) deontological precepts, particularly the challenges posed by their conflict with teleological moral demands in certain situations, as well as the difficulty of empirically ascertaining that a moral principle has in fact given the agent his reason for action, as the Mu'tazilites attempt to do. These were difficulties which Aš'arite critics of Mu'tazilite moral claims were quick to pick up on, and it is in the light of such hostile fire that the coherence of the Mu'tazilite position on the evilness of lies is examined. This is the principal focus of this essay, and it is complemented by an examination of how the principle carries over to the realm of divine morality: can God tell a lie? If not, why not? And what does this reveal about the ordering of moral values in Mu'tazilite thought? (shrink)
Textual evidence preserved in two still unpublished manuscripts strongly suggests that there once existed an alternative version of Miskawayhghar, the Minor Book of Triumph. The article discusses possible explanations for why Miskawayh may have composed two recensions of his Fawz and compares structure and content of the alternative version with the edited standard version. The one passage which is contained in the alternative Fawz only is presented in Arabic with an English translation. Part of this additional material is parallel to (...) al-Fbs I al-m, namely its division of natural sciences, and may ultimately derive from a no longer extant treatise by Paul the Persian. An appendix provides the Arabic text and English translation of a hitherto unknown fragment of al-Balkhs saying that the world has a causative, but no temporal beginning. (shrink)
Carlos Pereda califica mi concepción de la moral de realismo particularista y objeta a mi defensa tanto del realismo como del particularismo. En mi respuesta trato de mostrar cómo nuestras discrepancias en torno al papel de los principios en la deliberación moral es, excepto en un punto crucial, cuestión de énfasis. No ocurre lo mismo, sin embargo, con mi reivindicación del realismo moral, pues parte de lo que intento mostrar en el libro es que los programas constructivistas de los que (...) habla Pereda no pueden pensarse coherentemente. \\\ Carlos Pereda presents my view about morality as a sort of particularist realism and objects both to my defence of realism and that of particularism. In my reply, I argue that our discrepancies about the role of principies in moral deliberation is, except in a crucial respect, a matter of emphasis. Something quite different happens, however, with my vindication of moral realism. For part of what I try to show in my book is that constructivist programs like the one suggested by Pereda cannot be coherently thought. (shrink)
Upshot: New publications about Niklas Luhmann and his theory of social systems address the question of Luhmann’s epistemological standpoints. A publication on the “ontologies of the modern world” hastily describes social conventions and processes of stabilization as modern ontologies and a new handbook on Luhmann’s life, oeuvre and impact underestimates the major contribution of constructivism in Luhmann’s theory. Although the two books are comprehensive and informative, they do not make enough use of the constructivist potential to explain both Luhmann’s theory (...) as founded upon constructivist epistemology and the processes of modernization. (shrink)