He argues that knowledge has been desacralized in the modern period, that is, separated from its divine source—God—and calls for its resacralization through sacred traditions and sacred science. Although Islam and Sufism are major influences on his writings, his perennialist approach inquires into the essence of all orthodox religions, regardless of their formal particularities. He is considered a key thinker on the environment, particularly in terms of Islamic environmentalism and resacralization of nature. He is the author of over fifty books and more than five hundred articles.