In due sequence we must consider those acts whereby external things are offered to God. These give rise to a twofold consideration: (1) Of things given to God by the faithful; (2) Of vows, whereby something is promised to Him.

Under the first head we shall consider sacrifices, oblations, first-fruits, and tithes. About sacrifices there are four points of inquiry:

(1) Whether offering a sacrifice to God is of the law of nature?

(2) Whether sacrifice should be offered to God alone?

(3) Whether the offering of a sacrifice is a special act of virtue?

(4) Whether all are bound to offer sacrifice?