This article traces the early and medieval Islamic scholarship to the development of critical and scientific thinking and how they contributed to the development of an Islamic theory of epistemology and scientific thinking education. The article elucidates how the Qur'an and the Sunna of Prophet Muhammad have also contributed to the development of Islamic epistemology and the production of the scientific thinking method. In this way, the study has elaborated on exploring the relationship between Islamic piety and critical and scientific thinking as promoted in the Qur'an and the traditions of the Prophet and early Muslim scholars and medieval scholars of Islam. Following from this elaboration, the author elucidated how these scholars developed an Islamic pedagogy and curriculum theory commensurate with the spirit of Islam for promoting critical and scientific thinking. The article ends on notes of and implications for developing scientific thinking in modern Islamic education based on the past legacy of Islamic theory of education.