The more recent literature on Islamic economics is largely about Islamic financial instruments and institutions. It might give an impression as if the main difference between conventional and Islamic economics is in the instruments, rather than foundational aspect. Islamic economics is not about the prohibition of certain goods and services. It is a vastly different economic system whose answers to the core economic questions vary significantly. It is important to start from the foundation Islamic economics by redefining assumptions, developing new theories of microeconomics and macroeconomics, and offering testable models from the Islamic paradigm. This paper is an attempt to redefine Islamic economics as a new economic paradigm based on the distinctive axiomatic feature of Islamic worldview. In order to do that, the paper first presents evidences of the crises of capitalism and search for alternative paradigm. Second, it outlines the origin of capitalism within the Western secular worldview. Third, it presents the Islamic worldview from anthropological, epistemological, and teleological perspectives. Fourth, it redefines Islamic economics as alternative economic paradigm