PART IV. -- SUPPLEMENT. INTRODUCTION.

S. THOMAS AQUINAS did not live to complete the Summa. His editors have tried to supply what is wanting from his other works. For the purpose which the present writer has in view he will freely use the materials thus provided, or any other standard authorities, such as the Doctor Dubitantium of Bishop Taylor, the contributions to our science made by Sanderson when he was professor at Oxford, or any others.

No attempt is made to consider all possible cases; only such are selected as are most likely to occur, or are most serviceable illustrations and expansions of what has preceded. It was said in the preface, but may now be repeated, that only a cursory glance can here be given at many topics -- e.g., the obligations of the state and the citizen -- for each such topic would require a volume. Nothing more can be aimed at than to indicate, before this Supplement is concluded, some of the problems which Moral Theology must consider, since their solution belongs to the law of God, although those problems are here left unsolved.

To prove every proposition laid down in a brief manual of this kind would be practically impossible. And the elements of every science require the writer of them to assume a dogmatic tone even when proof could readily be furnished. Let it suffice, then, that the present writer has taken his utmost pains to lay down no proposition which does not express either the common law of the Catholic Church or direct deduction from the revealed law of God. Where he may have erred he submits his judgment to the lawful authority, duly expressed, of the Church from which he has received his commission as priest and teacher.

Some questions which seemed open to discussion among those who are loyal to the moral authority of the Christian Church have been indicated in parentheses, even when the writer might for his own part regard some of them as closed questions.

{1} Pars Tertia breaks off at qu. XC. 82