The non-binding Islamic legal rulings or opinions (fatwās), which are issued by Muslim scholars or Islamic religious institutions in response to questions asked by Muslim individuals may be said to represent the most dynamic genre of (past or present) Islamic legal literature. It was traditionally the case that the practice of iftā’ resided in the individual authority and effort of Muslim scholars. However, after national and international Islamic religious institutions were established at the beginning of the twentieth century, this practice has largely become the responsibility of specific bodies tasked with issuing fatwās. Saudi Arabia’s Dār al-Iftā’ (the General Presidency of Scholarly Research and Iftā’) and Turkey’s Diyanet (the Presidency of Religious Affairs) are concrete products of the twentieth century. Both institutions provide an idiosyncratic insight into the practice of iftā’ and more specifically its development and application within two very different societies. One of the primary concerns of this thesis is therefore to identify the authority, function and role of the two institutions and their official fatwās in their respective environments. The thesis compares the fatwās issued by the two institutions with the intention of determining which Islamic legal concepts and methodologies are applied. In addition, the discussion will also assess how the institutions interpreted authoritative sources of Islamic law and the process through which they came to arrive at divergent, and even opposed, interpretations. The thesis provides insight into the dynamic interconnection and interaction between Islamic legal methodologies and societal realities by examining these two Islamic modern institutions and focusing on their legal interpretation or edicts (fatwās). The active dimension of Islamic law is visibly rendered within the cultural, legal, political and social context in which the fatwā mechanism provides new regulations and rulings. The analysis converges upon the proposition that differences of opinion do not derive from the fundamental Islamic legal sources, the Qur’an and Sunna, but can instead be traced back to the different contextual environments in which the fatwās emerged, thus illustrating the strong connection between contextual elements and Islamic legal methodologies. In analysing fatwās issued by the two institutions on similar subjects within a comparative framework, I seek to explore the interaction between Islamic legal methodologies and the contexts in which they are applied. I therefore provide a contextual and methodological analysis of contemporary fatwās issued by the two institutions. After identifying four thematic criteria (the predominant madhhab affiliation, legal systems, political structures, and social presumptions and cultural practices), the thesis then proceeds to identify the points at which the two institutions converge and diverge in each of these respects. The study also uses the fatwās to demonstrate how the two institutions employ different Islamic legal concepts and principles when addressing identical issues. Finally, the thesis seeks to introduce an advanced comparative model for the study of fatwās that encompasses institutions (as social and religious interpreters), Islamic legal theories and methodologies (as an essential source of the law) and the social context in which fatwās emerge. I envisage that a comparative analysis of the Dār al-Iftā’ and the Diyanet will encourage academic researchers to investigate the institutionalised iftā’ practice and to explore differences of opinion in the modern world. Institutionalised fatwās are important elemental materials that provide considerable insight into the points at which Islamic law encounters rapidly changing socio-cultural, socio-legal and socio-political circumstances.

This paper is an attempt to describe how two religious edicts by the current Egyptian grand mufti relate to an ongoing theological debate in the Muslim world on the nature of miracles and the state of mankind between life and death. The study illustrates how the mufti adheres to the Sunni theological school of Ash‘ariyya and in what way said school has emerged as a theological middle ground between the literal and interpretative schools of thought. The study also reveals how the Mufti as a guardian of the faith must operate within a secularising context and what strategies are possible for him to utilise if he is to meet the demands of a modernised society whilst retaining a coherent religious explanation. In his office as grand mufti, Ali Goma may well be described as a traditionalist where theological matters are considered even if the governmental institute of Dār al- iftā has been modernised under his supervision and now uses 24 hour phone lines, e-mail, facebook and has an official webpage and translates many of its edicts into other languages than Arabic. This means that Dār al-iftā and Ali Goma are communicating an official Islam not only to the Muslims of Egypt, but has transformed from a national institute to a player in the era of globalisation.

Neste trabalho desenvolvemos duas séries de EODs operando em regime simultâneo de modulação das componentes de fase e de amplitude de uma frente de luz (Modulação Complexa Completa MCC). A primeira destas séries foi constituída por Hologramas de Fourier calculados através do Algoritmo Iterativo da Transformada de Fourier (Iterative Fourier Transform Algorithm IFTA) e a segunda, por Hologramad de Fresnel cujo cálculo da propagação da luz foi obtido por filmagem linear espacial proveniente da solução da Equação de Helmholtz no domínio da frequência. Nos dois casos, a Modulação Complexa Completa foi implementada fisicamente empregando, para realizar a modulação de fase, um micro-relevo gravado em um filme de DLC (Diamond Like Carbon) depositado sobre um substrato de vidro. Sobre este relevo foi implementada a modulação de amplitude, através da deposição de um filme de alumínio, no qual foram realizadas micro-aberturas diferentes cujas áreas eram proporcionais à amplitude em cada pixel. Nos Hologramas de Fourier, uma diferente espessura do filme DLC localizada sobre cada pixel foi responsável pela modulação do valor de fase relativo àquele ponto. Nos Hologramas de Fresnel, a combinação de duas espessuras diferentes do filme de DLC em cada pixel foi responsável pela modulação do valor de fase relativo a cada ponto. Os elementos foram caracterizados física e opticamente e produziram imagens de reconstrução totalmente livres de ruídos do tipo speckle. Também em caráter de avaliação dos resultados foi efetuada a comparação entre as imagens de reconstrução óptica produzidas pelos Hologramas de Fresnel com MCC com as produzidas por Hologramas de Fresnel convencionais em regime de modulação de fase. / In this work, we developed two sets of DOESs able to modulate both phase and amplitude components of light simultaneously (Complete Complex Modulation CCM). The first set is composed of Fourier Holograms calculated by Iteractive Fourier Transform Algorithm (IFTA). The second set is composed by Fresnel Holograms, which light propagation was calculated by spatial linear filtering obtained from the solution of the Helmholtz Equation in the frequency domain. In both cases, Complete Complex Modulation was physically implemented by a micro-relief, for phase modulation, recorded on a Diamond Like Carbon (DLC) film deposited on a glass substrate. Amplitude modulation was implemented on a aluminum fim layer deposited on this relief. In this layer, micro-appertures proportional to the amplitude on each pixel, were recorded. Phase modulation in each pixel of the Fourier Holograms was achivied by different thicknesses of the DLC film. For Fresnel Holograms, phase modulation was achieved by combining two different thicknesses of DLC film inside each pixel. The elements were physically and optically characterized and produced reconstruction images completly free of speckle like noise. The optical reconstruction images produced from Fresnel Holograms working in CCM regime and convencional phase-only modulated Fourier Holograms were compared.

Neste trabalho desenvolvemos duas séries de EODs operando em regime simultâneo de modulação das componentes de fase e de amplitude de uma frente de luz (Modulação Complexa Completa MCC). A primeira destas séries foi constituída por Hologramas de Fourier calculados através do Algoritmo Iterativo da Transformada de Fourier (Iterative Fourier Transform Algorithm IFTA) e a segunda, por Hologramad de Fresnel cujo cálculo da propagação da luz foi obtido por filmagem linear espacial proveniente da solução da Equação de Helmholtz no domínio da frequência. Nos dois casos, a Modulação Complexa Completa foi implementada fisicamente empregando, para realizar a modulação de fase, um micro-relevo gravado em um filme de DLC (Diamond Like Carbon) depositado sobre um substrato de vidro. Sobre este relevo foi implementada a modulação de amplitude, através da deposição de um filme de alumínio, no qual foram realizadas micro-aberturas diferentes cujas áreas eram proporcionais à amplitude em cada pixel. Nos Hologramas de Fourier, uma diferente espessura do filme DLC localizada sobre cada pixel foi responsável pela modulação do valor de fase relativo àquele ponto. Nos Hologramas de Fresnel, a combinação de duas espessuras diferentes do filme de DLC em cada pixel foi responsável pela modulação do valor de fase relativo a cada ponto. Os elementos foram caracterizados física e opticamente e produziram imagens de reconstrução totalmente livres de ruídos do tipo speckle. Também em caráter de avaliação dos resultados foi efetuada a comparação entre as imagens de reconstrução óptica produzidas pelos Hologramas de Fresnel com MCC com as produzidas por Hologramas de Fresnel convencionais em regime de modulação de fase. / In this work, we developed two sets of DOESs able to modulate both phase and amplitude components of light simultaneously (Complete Complex Modulation CCM). The first set is composed of Fourier Holograms calculated by Iteractive Fourier Transform Algorithm (IFTA). The second set is composed by Fresnel Holograms, which light propagation was calculated by spatial linear filtering obtained from the solution of the Helmholtz Equation in the frequency domain. In both cases, Complete Complex Modulation was physically implemented by a micro-relief, for phase modulation, recorded on a Diamond Like Carbon (DLC) film deposited on a glass substrate. Amplitude modulation was implemented on a aluminum fim layer deposited on this relief. In this layer, micro-appertures proportional to the amplitude on each pixel, were recorded. Phase modulation in each pixel of the Fourier Holograms was achivied by different thicknesses of the DLC film. For Fresnel Holograms, phase modulation was achieved by combining two different thicknesses of DLC film inside each pixel. The elements were physically and optically characterized and produced reconstruction images completly free of speckle like noise. The optical reconstruction images produced from Fresnel Holograms working in CCM regime and convencional phase-only modulated Fourier Holograms were compared.