This book explores the methodological foundation of Islamic thought premised on the cardinal principle of Tawhid, meaning the Oneness of God as the universal law. The consequential methodological worldview arising from the monotheistic unity of knowledge is explained as the theory of consilience, meaning unity of knowledge as the primal ontological reality leading to its epistemological and phenomenological essentials of reasoning and thereby configuring reality. Masudul Alam Choudhury presents a non-mathematical exposition of the theory and applications of Meta-Science of Tawhid, and brings out the essential monotheistic methodological worldview of science.