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?