The Maker first exercised this right when He put into His creature's soul a sense of right and wrong, which is nothing more than conscience, or as it is called here, natural law. To this law is subject every human being, pagan, Jew and Christian alike. No creature capable of a human act is exempt. The provisions of this law consider the nature of our being, that is, the law prescribes what the necessities of our being demand, and it prohibits what is destructive thereof. Our nature requires physically that we eat, drink and sleep. Similarly, in a moral sense, it calls for justice, truthfulness, respect of God, of the neighbor, and of self. All its precepts are summed up in this one: ''Do unto others as you would have them do unto you "—the golden rule.
Thence flows a series of deducted precepts calculated to protect the moral and inherent rights of our nature. But we are more concerned here with what is known as the positive Law of God, given by Him to man by word of mouth or revelation. We believe that God gave a verbal code to Moses who promulgated it in His name before the Jewish people to the whole world. It was subsequently inscribed on two stone tables, and is known as the Decalogue or Ten Commandments of God. Of these ten, the first three pertain to God Himself, the latter seven to the neighbor; so that the whole might be abridged in these two words, "Love God, and love thy neighbor." This law is in reality only a specified form of the natural law, and its enactment was necessitated by the iniquity of men which had in time obscured and partly effaced the letter of the law in their souls.
Latterly God again spoke, but this time in the person of Jesus Christ. The Saviour, after confirming the Decalogue with His authority, gave other laws to men concerning the Church He had founded and the means of applying to themselves the fruits of the Redemption. We give the name of dogma to what He tells us to believe and of morals to what we must do. These precepts of Jesus Christ are contained in the Gospel, and are called the Evangelical Law. It is made known to us by the infallible Church through which God speaks.
Akin to these divine laws is the purely ecclesiastical law or law of the Church. Christ sent forth His Church clothed with His own and His Father's authority. ''As the Father sent me, so I send you." She was to endure, perfect herself and fulfill her mission on earth. To enable her to carry out this divine plan she makes laws, laws purely ecclesiastical, but laws that have the same binding force as the divine laws themselves, since they bear the stamp of divine authority. God willed the Church to be; He willed consequently all the necessary means without which she would cease to be. For Catholics, therefore, as far as obligations are concerned, there is no practical difference between God's law and the law of His Church. Jesus Christ is God. The Church is His spouse. To her the Saviour said: "He that heareth you, heareth me, and he that despiseth you despiseth Me."
A breach of the law is a sin. A sin is a deliberate transgression of the Law of God. A sin may be committed in thought, in desire, in word, or in deed, and by omission as well as by commission. It is well to bear in mind that a thought, as well as a deed, is an act, may be a human and a moral act, and consequently may be a sin. Human laws may be violated only in deed; but God, who is a searcher of hearts, takes note of the workings of the will whence
springs all malice. To desire to break His commandments is to offend Him as effectually as to break them in deed; to relish in one's mind forbidden fruits, to meditate and deliberate on evil purposes, is only a degree removed from actual commission of wrong.
Evil is perpetrated in the will, either by a longing to prevaricate or by affection for that which is prohibited. If the evil materializes exteriorly, it does not constitute one in sin anew, but only completes the malice already existing. Men judge their fellows by their works; God judges us by our thoughts, by the inner workings of the soul, and takes notice of our exterior doings only in so far as they are related to the will. Therefore it is that an offense against Him, to be an offense, need not necessarily be perpetrated in word or in deed; it is sufficient that the will place itself in opposition to the Will of God, and adhere to what the Law forbids.
Sin is not the same as vice. One is an act, the other is a state or inclination to act. One is transitory, the other is permanent. One can exist without the other. A drunkard is not always drunk, nor is a man a drunkard for having once or twice overindulged. In only one case is vice less evil than sin, and that is when the inclination remains an unwilling inclination and does not pass to acts. A man who reforms after a protracted spree still retains an inclination, a desire for strong drink. He is nowise criminal so long as he resists that tendency. But practically vice is worse than sin, for it supposes frequent wilful acts of sin of which it is the natural consequence, and leads to many grievous offenses. A vice is without sin when one struggles successfully against it after the habit has been retracted. It may never be radically destroyed. There may be unconscious, involuntary lapses under the constant pressure of a strong inclination, as in the vice of cursing, and it remains innocent as long as it is not willfully yielded to and indulged. But to yield to the gratification of an evil desire or propensity, without constraint, is to doom oneself to the most prolific of evils and to lie under the curse of God.
Source: Moral Briefs by Rev. John H. Stapleton, Imprimatur 1904