Pope Francis' encyclical Laudato si' is striking for its relationship to the natural sciences and in particular in terms of the integration of scientific ecology that it reflects. It is undeniable -and has been recognized - that the Pope has drunk from the best-documented scientific wells which lend this religious text an air of seriousness and credibility. This paper intends to show how this integration is not purely technical in its use of scientific discourse. It is also paradigmatic, introducing an original way of thinking in the contexts of the Roman Catholic Church's Social Doctrine and of theology, so as to develop an authentic theology of ecology. Paragraphs 2 and 49 of the encyclical voice the idea that scientific discourse, identifying the ecological crisis, allows the human being to be attentive to the suffering of the planet and thus to number it among the category of the poor, to whom the Church has always sought to bring help and relief. Still more astonishingly, the scientific definition of ecology present in LS 138 serves as a starting point for the Pope in establishing the project of integral ecology. Highlighting the fact that "everything is connected", the Pope introduces a new way of thinking in theology in order to enrich its expression for the Church's dialogue with ecology and its integration of contemporary societal issues.