THE TENTH (NINTH) COMMANDMENT: "Thou Shalt Not Covet Thy Neighbor's Wife."

St. John says in his first Epistle that "all that is in the world is the

concupiscence of the flesh, the concupiscence of the eyes, and the pride of

life."¹ Now, all that is desirable is included in these three, two of which

are forbidden by the precept: "Thou shalt not covet thy neighbor's house."²

Here "house," signifying height, refers to avarice, for "glory and wealth

shall be in his house."³ This means that he who desires the house, desires

honors and riches. And thus after the precept forbidding desire for the

house of one's neighbor comes the Commandment prohibiting concupiscence of

the flesh: "Thou shalt not covet thy neighbor's wife."⁴

Because of the corruption which resulted from the Fall, none has been free

from concupiscence except Christ and the glorious Virgin. And wherever

there is concupiscence, there is either venial or mortal sin, provided that

it is allowed to dominate the reason.⁵ Hence the precept is not, let sin

not be; for it is written: "I know that there dwelleth not in me [that is

to say, in my flesh] that which is good."⁶

First of all, sin rules in the flesh when, by giving consent to it,

concupiscence reigns in the heart. And, therefore, St. Paul adds "so as to

obey the lusts thereof" to the words: "Let not sin reign in your mortal

body."⁷ Accordingly the Lord says: "Whosoever shall look on a woman to lust

after her, hath already committed adultery with her in his heart."⁸ For

with God the intention is taken for the act.

Secondly, sin rules in the flesh when the concupiscence of our heart is

expressed in words: "Out of the abundance of the heart the mouth

speaketh."⁹ And again: "Let no evil speech proceed from your mouth."¹⁰

Therefore, one is not without sin who composes frivolous songs. Even the

philosophers so thought, and poets who wrote amatory verses were sent into

exile. Lastly, sin rules in the flesh when at the behest of desire the

members are made to serve iniquity: "As you have yielded your members to

serve uncleanness and iniquity unto iniquity."¹¹ These, therefore, are the

progressive steps of concupiscence.