16. In our times the students in your junior and senior seminaries can less than ever afford to be strangers to the study of physical and natural science. To it, therefore, they must apply themselves-but in due measure and in wise proportions. It is by no means necessary that in the scientific course annexed to the study of philosophy the professors should feel themselves obliged to expound in detail the almost innumerable applications of physical and natural sciences in the different branches of human industry. It is enough that their pupils have an accurate knowledge of the main principles and summary conclusions, so as to be able to solve the objections which infidels draw from these sciences against the teachings of Revelation.