community: first,
fidelity; secondly, reverence; thirdly, service. Fidelity to his
master consists in his not giving sovereign honor to another: and
this is the sense of the first commandment, in the words "Thou shalt
not have strange gods." Reverence to his master requires that he
should do nothing injurious to him: and this is conveyed by the
second commandment, "Thou shalt not take the name of the Lord thy God
in vain." Service is due to the master in return for the benefits
which his subjects receive from him: and to this belongs the third
commandment of the sanctification of the Sabbath in memory of the
creation of all things.

To his neighbors a man behaves himself well both in particular and in
general. In particular, as to those to whom he is indebted, by paying
his debts: and in this sense is to be taken the commandment about
honoring one's parents. In general, as to all men, by doing harm to
none, either by deed, or by word, or by thought. By deed, harm is
done to one's neighbor--sometimes in his person, i.e. as to his
personal existence; and this is forbidden by the words, "Thou shalt
not kill": sometimes in a person united to him, as to the propagation
of offspring; and this is prohibited by the words, "Thou shalt not
commit adultery": sometimes in his possessions, which are directed to
both the aforesaid; and with this regard to this it is said, "Thou
shalt not steal." Harm done by word is forbidden when it is said,
"Thou shalt not bear false witness against thy neighbor": harm done
by thought is forbidden in the words, "Thou shalt not covet."

The three precepts that direct man in his behavior towards God may
also be differentiated in this same way. For the first refers to
deeds; wherefore it is said, "Thou shalt not make . . . a graven
thing": the second, to words; wherefore it is said, "Thou shalt not
take the name of the Lord thy God in vain": the third, to thoughts;
because the sanctification of the Sabbath, as the subject of a moral
precept, requires repose of the heart in God. Or, according to
Augustine (In Ps. 32: Conc. 1), by the first commandment we reverence
the unity of the First Principle; by the second, the Divine truth; by
the third, His goodness whereby we are sanctified, and wherein we
rest as in our last end.

Reply Obj. 1: This objection may be answered in two ways. First,
because the precepts of the decalogue can be reduced to the precepts
of charity. Now there was need for man to r