Comenius wrote two textbooks covering one hand Physicae synopsis, published in the field of natural science or, as it was 1633, and on the other hand one part of then generally called, physics. It is on the famous work Janua linguarum reserata that deals with nature. The first edition of the latter work appeared in 1631, the second, completely rewritten edition in 1649. In neither of these works did Comenius confine himself to the Aristotelian-scholastic explanations of nature, which were traditional in schools of those times, but he worked out a system of his own, in which his main concern was for physics to be really “Christian”, i e. based on the Bible, and to present an image of nature according to the latest knowledge attained in those times. Comenius had been interested in physics ever since his Herborn studies, where J. H. Alsted was his guide and, above all, his most favourite teacher. It was there that he got acquainted with the then modern physics of Paracelsus. Paracelsus’ tendency, which was neoplatonic in principle, was strengthened then by Augustinian ideas. Later on it was further strengthened on the one hand by the study of Cusan’s works and those of the Brotherhood of Rose Cross school of thought, on the other hand by his getting acquainted with German mysticism, especially that of Böhm, which is echoed in the views about nature expressed in the work Centrum Securitatis, where we find, in a nutshell, all his later concept of nature. At Leshno he got to know the works of Campanella and Bacon, as well as the work of Daniel Sennert called “De chymicorum cum Aristotelicis et Galenicis consensu ac dissensu”, which strengthened and deepened his philosophical orientation in natural science, which then found expression in both the above-mentioned textbooks. His survey of physics originated from the lectures which Comenius had prepared for his lessons of physics at the Leshno Grammar School. The world is described here as a huge organism, whose parts are ail mutually interrelated; the alchemic tendency of Paracelsus is apparent everywhere. The methodological approach to the subject-matter is exemplary. In the general part Comenius deals with the origin of the world, its three fundamental principles and its three main attributes. In the special part he covers progressively all the objects of the material world. He begins by explaining the four elements, which are dissolved by heat and turned into vapour and then mixed together, their condensation and solidification giving rise to all the objects of the visible world, from celestial bodies to man. His interpretations of nature in the Gate of Languages are basically of the same content but written with a different approach. The content is adapted to the intellectual capacity of younger readers, therefore Comenius omits philosophical speculations about nature and concentrates more on description. Moreover, Comenius did not aim at interpreting only nature here. The subject-matter about nature in the Gate of Languages is organically included in a complex explanation of the world covering not only nature but also all the results of man’s work, both manual and mental, crafts and trades, science, ethical principles and the social system, whereby the Gate of Languages became the first pansophic attempt of Comenius. This pansophic approach is even more apparent in the second, completely rewritten edition of 1649, which Comenius rightly called ’’Children’s Encyclopedia“ or ’’Little Pansophia”. Both the above-mentioned works give us an idea of what Comenius thought a textbook in a certain subject should be like, both for the lower and for the higher grade of school. His aim is a complex, organic explanation of the subject-matter, in which nothing essential is left out, but the approach is different for each age group. The younger readers are given, above all, a description of objects as they can see them in the world around, while the older ones are also given an interpretation of the substance and origin of these objects.