Further, not only can faith and reason never contra- dict one another, but they mutually aid one another, for right reason proves the foundations of faith, and by its light fosters the science of divine things ; and faith frees and preserves reason from error, and fills it with abundant knowledge. Hence, so far is the Church from opposing the study of human arts and sciences, that she in many ways helps and promotes it. For the Church does not ignore nor contemn the benefits which the arts and sciences have rendered to human life, but rather holds that, coming from God, the Lord of all sciences, if they are rightly followed, they, by the help of his grace,, lead to God. Nor does the Church forbid that any science should in its own circle use its own principles and methods ; but, while recognising this THE CHURCH AND SCIENCE just liberty, it is vigilantly on the alert lest sciences, by opposing the divine teaching, should take to themselves errors, or, skirmishing beyond their own spheres, should usurp and disturb the function of faith. For the teaching of faith which God has revealed haft not been given like a philosophical discovery, to be perfected by human wit ; but has been delivered as a divine deposit to the Spouse of Christ, to be faithfully kept and infallibly declared. And it is on account of this that that meaning of the sacred dogmas is per- petually to be retained which our holy Mother the