The paper aims to introduce the encyclopaedic project presented by the reformed philosopher and theologian Johann Heinrich Alsted (1588–1638) and study it as one of the possible sources of the pansophism of the Czech philosopher, theologian and educational reformer Jan Amos Comenius (1592–1670). For this reason, the author first briefly describes the genesis, development and structure of Alsted’s encyclopaedic work with a special focus on his mature and monumental Encyclopaedia septem tomis distincta (1630). The crucial part of the paper is devoted to comparing Alsted’s and Comenius’s conceptions of metaphysics, physics (or philosophy of nature) and other important fields of their shared interest. The author concludes that Comenius was undoubtedly influenced by Alsted in structural and terminological matters; furthermore, that both Alsted and Comenius inclined to base their philosophy of nature on so-called Mosaic physics and tended to understand metaphysics as a primary science not only in view of its dignity, but also with regard to its place in the system of sciences and in the curriculum.