« L’union fait la force », dit l’adage : de tout temps, l’être humain a fait jouer le meilleur de son capital social (Putnam 2001) pour s’allier avec d’autres et faire société (Ponthieux 2006). Les groupes ainsi formés, unis par des intérêts communs et selon des géographies variables, se trouvent invariablement confrontés tôt ou tard à d’autres groupes aux objectifs parfois bien différents des leurs. Quel que soit le terme employé ou la théorisation envisagée pour qualifier et modéliser les modalités de cette rencontre, l’interaction force invariablement les groupes impliqués à confronter les habitudes et visions des uns et des autres. Mais que faire lorsqu’une incompatibilité se pose, lorsque les intérêts des uns et des autres ne semblent pas pouvoir se réaliser simultanément ? L’idée défendue dans cette thèse est qu’une intégration maximale des parties dans les processus de gestion du patrimoine accompagnée d’une réforme des systèmes de justice et d’un enseignement de qualité pourra faire du patrimoine un vecteur de développement à part entière. Afin de démontrer la pertinence de cette affirmation, deux cas d’étude bien différents mais néanmoins complémentaires ont fait l’objet d’une recherche approfondie : la mosquée-cathédrale de Cordoue (Espagne) et la mosquée de Babri à Ayodhya (Inde). Toutes deux font l’objet de conflits à géométries variables, entre des groupes politiques et religieux poursuivant des objectifs distincts. A travers une analyse des arguments et des modes d’action des différents acteurs des deux débats, cette thèse aboutit à la conclusion que ces conflits patrimoniaux relèvent directement des droits culturels des groupes concernés. Sans proposer de solution unique, est esquissée à l’issue de cette recherche une approche compréhensive et inclusive faisant du patrimoine et de la culture qui l’inclut un outil de développement pour les sociétés qui l’accueillent.

La présente thèse doctorale fait état du problème que soulèvent l’art d’église et ses mutations actuelles dans les paroisses catholiques du Québec. Ayant connu ses heures de gloire, cette tradition artistique mute et il est maintenant difficile d’en cerner la dynamique. Une approche méthodique s’avère donc pertinente pour situer le problème dans une juste perspective, en apprécier la nature et la pérennité et suggérer des balises aptes à en guider la solution. Tout d’abord, par l’histoire des comités d’art sacré des diocèses catholiques de Québec et de Montréal, qui sont les témoins privilégiés de l’évolution des conceptions de l’art d’église de leurs paroisses depuis le concile Vatican II, par la recension de pratiques nouvelles dans quelques-unes de ces églises et par un inventaire des constructions et des réaménagements partiels d’églises paroissiales dans les trois diocèses les plus populeux, l’on se fait une idée assez juste de la situation actuelle de l’art d’église des paroisses catholiques du Québec. Par la suite, en évaluant les chances de son acculturation, selon un outillage théorique approprié, et en retenant des leçons de l’histoire presque bimillénaire de l’art d’église, le rapport entre cette tradition artistique et ses mutations actuelles au Québec apparaît moins problématique. Malgré la baisse marquée des commandes ecclésiastiques dans les années qui ont suivi le concile, ce type d’art d’église perdure dans la sphère publique, en corrélation avec l’intérêt de nombreux citoyens envers ce patrimoine. Ainsi, cette tradition artistique se poursuit d’une manière inédite, sujette à évoluer. / In this doctoral thesis we examine the problem of the transformations taking place in church art in the Catholic parishes in Quebec. After enjoying a lengthy heyday, this artistic tradition is now in a state of mutation not always easy to grasp. We need to take a methodical approach when placing the problem in its proper perspective, attempting to comprehend its nature and timelessness, and proposing suitable guidelines for finding a solution. Firstly, we can arrive at a reasonably accurate notion of the current state of church art in the Catholic parishes in Québec through a careful examination of the history of the sacred art committees in the Catholic dioceses of Québec, Montréal and Saint-Jean-Longueuil, which were on the front lines of the evolution of church art in their parishes after the Second Vatican Council, by examining the new observances in a few of these churches, and by taking an inventory of new constructions and partial transformations of parish churches in the most heavily populated dioceses. Secondly, using an appropriate theoretical system, in order to assess the possibility for this art to integrate elements of living culture and keeping in mind what we have learned from almost two millenia of church art, we can conclude that the relationship between this artistic tradition and its present evolution in Québec is less problematic than it appears. In spite of the conspicious drop in orders for religious art objects in the years following the Council, church art survives in the public domain thanks to the interest in this area of our heritage on the part of many citizens. Consequently, this artistic tradition survives in an original way, and will continue to evolve.

Since the beginning of the 21st century, the future of religious heritage has provoked consideration within the fields of law, history, architecture and heritage. The origin of this problem is explained both by the decline in traditional worship practices, essentially Catholic in France, from the 1960s onwards, and by the Church’s lack of human and financial resources, which has resulted in the appearance of veritable "religious desert". This process, related to society’s secularisation, is expected to increase because of the likelihood of these two factors intensifying. If convents, monasteries, seminaries and other Catholic religious buildings have already been affected by this phenomenon, parish church buildings are now in turn losing their original function. Quebec has also experienced this phenomenon, but its historical and legal contexts have accelerated the transformation of churches which in turn resulted in the establishment of a "churches Plan" aiming at preserving church buildings by converting them.In this thesis, that pioneering programme is used in relation to the Lyons Saint-Etienne urban area, as a lens through which to read the French situation and as a tool for generating methods adapted to its specific context.The first part summarises the specific heritage and legal knowledge bases from Quebec and France concerning their parish churches, which is necessary for understanding the two contexts. The second part is an observational study, which defines the territory and creates an inventory of the corpus of research. We first provide an inventory of 429 parish churches within the territory studied here. From an analysis of their transformations, we propose three major typologies ("historical", "19th-century" and "20 h-century " churches), Using the cases of church conversions in ou corpus, we analyse the degree of compatibility between their previous worship use and their new uses, and then formulate hypotheses relating architectural interventions for adaptative reuse to restoration theories. The third part is an action-research interventional study. Three representative case studies from each church typology have been selected, in the town of Montarcher, Givors and Villeurbanne. For each case, a participatory approach has been set up with the municipality, inhabitants and associations, in order to propose reconversion scenarios adapted to local needs.This work shows that the demolition of parish churches, widely perceived as a common good, threatens the transmission of local identities. It therefore seems essential to start a global reflection on the evolution of this heritage, one which takes into account territorial issues, citizens' demands and the architectural diversity of these buildings. We show that the architect, through both his sensitivity to the place and his technical, can play a central role in implementing of these reflection. / Since the beginning of the 21st century, the future of religious heritage has provoked consideration within the fields of law, history, architecture and heritage. The origin of this problem is explained both by the decline in traditional worship practices, essentially Catholic in France, from the 1960s onwards, and by the Church’s lack of human and financial resources, which has resulted in the appearance of veritable "religious desert". This process, related to society’s secularisation, is expected to increase because of the likelihood of these two factors intensifying. If convents, monasteries, seminaries and other Catholic religious buildings have already been affected by this phenomenon, parish church buildings are now in turn losing their original function. Quebec has also experienced this phenomenon, but its historical and legal contexts have accelerated the transformation of churches which in turn resulted in the establishment of a "churches Plan" aiming at preserving church buildings by converting them.In this thesis, that pioneering programme is used in relation to the Lyons Saint-Etienne urban area, as a lens through which to read the French situation and as a tool for generating methods adapted to its specific context.The first part summarises the specific heritage and legal knowledge bases from Quebec and France concerning their parish churches, which is necessary for understanding the two contexts. The second part is an observational study, which defines the territory and creates an inventory of the corpus of research. We first provide an inventory of 429 parish churches within the territory studied here. From an analysis of their transformations, we propose three major typologies ("historical", "19th-century" and "20 h-century " churches), Using the cases of church conversions in ou corpus, we analyse the degree of compatibility between their previous worship use and their new uses, and then formulate hypotheses relating architectural interventions for adaptative reuse to restoration theories. The third part is an action-research interventional study. Three representative case studies from each church typology have been selected, in the town of Montarcher, Givors and Villeurbanne. For each case, a participatory approach has been set up with the municipality, inhabitants and associations, in order to propose reconversion scenarios adapted to local needs.This work shows that the demolition of parish churches, widely perceived as a common good, threatens the transmission of local identities. It therefore seems essential to start a global reflection on the evolution of this heritage, one which takes into account territorial issues, citizens' demands and the architectural diversity of these buildings. We show that the architect, through both his sensitivity to the place and his technical, can play a central role in implementing of these reflection.