Sins against theological virtues are greatest sins as they directly offend God, according to Summan Theologica.

Mortal sins are mortal, I'm sure.  Sins are the opposite of God's goodness and repugnant to Him.  Never gave this much thought before.

Gotcha! Let he who is without sin cast the first stone.

NOTES taken during an Ignatian Retreat:

The Passions (anger,love, etc) are the ones that are usually disordered. Sins of the flesh are bad but the least of the Mortal Sins.

Sins of the Will (malice, hate) are worse still. Hearts are restless till with God.

Sins of the Mind are worse yet (heresy - sins against Faith). It is a great evil when the intellect is disordered.

Sins against Charity (hatred of God) are even more serious than sins against Faith.

Sin begets sin. Each sin spiritually weakens the Soul and reduces its ability to resist future sin.

"Vice is a mnster of so frightful mien, as to be hated, only need to be seen.

Yet seen too oft, familiar with her face, we first endure, then pity, then enbrace."

Alexander Poe

I think sins against purity are also ones that offend God most.

We read throught typos all the time, Bruno.  We're good at it cause we make so many.  LOL

Sins against the Holy Ghost
The sin or blasphemy against the Holy Ghost is mentioned in Matthew 12:22-32; Mark 3:22-30; Luke 12:10 (cf. 11:14-23); and Christ everywhere declares that it shall not be pardoned. In what does it consist? If we examine all the passages alluded to, there can be little doubt as to the reply.

Let us take, for instance, the account given by St. Matthew which is more complete than that of the other Synoptics. There had been brought to Christ "one possessed with a devil, blind and dumb: and he healed him, so that he spoke and saw". While the crowd is wondering, and asking: "Is not this the Son of David?", the Pharisees, yielding to their wonted jealousy, and shutting their eyes to the light of evidence, say: "This man casteth not out devils but by Beelzebub the prince of the devils." Jesus then proves to them this absurdity, and, consequently, the malice of their explanation; He shows them that it is by "the Spirit of God" that He casts out devils, and then He concludes: "therefore I say to you: Every sin and blasphemy shall be forgiven men, but the blasphemy of the Spirit shall not be forgiven. And whosoever shall speak a word against the Son of man, it shall be forgiven him: but he that shall speak against the Holy Ghost, it shall not he forgiven him, neither in this world, nor in the world to come."

So, to sin against the Holy Ghost is to confound Him with the spirit of evil, it is to deny, from pure malice, the Divine character of works manifestly Divine. This is the sense in which St. Mark also defines the sin question; for, after reciting the words of the Master: "But he that shall blaspheme against the Holy Ghost shall never have forgiveness", he adds at once: "Because they said: He hath an unclean spirit." With this sin of pure downright malice, Jesus contrasts the sin "against the Son of man", that is the sin committed against Himself as man, the wrong done to His humanity in judging Him by His humble and lowly appearance. This fault, unlike the former, might he excused as the result of man's ignorance and misunderstanding.

But the Fathers of the Church, commenting on the Gospel texts we are treating of, did not confine themselves to the meaning given above. Whether it be that they wished to group together all objectively analogous cases, or whether they hesitated and wavered when confronted with this point of doctrine, which St. Augustine declares (Serm. ii de verbis Domini, c. v) one of the most difficult in Scripture, they have proposed different interpretations or explanations.

St. Thomas, whom we may safely follow, gives a very good summary of opinions in II-II.14. He says that blasphemy against the Holy Ghost was and may be explained in three ways.

Sometimes, and in its most literal signification, it has been taken to mean the uttering of an insult against the Divine Spirit, applying the appellation either to the Holy Ghost or to all three Divine persons. This was the sin of the Pharisees, who spoke at first against "the Son of Man", criticizing the works and human ways of Jesus, accusing Him of loving good cheer and wine, of associating with the publicans, and who, later on, with undoubted bad faith, traduced His Divine works, the miracles which He wrought by virtue of His own Divinity.
On the other hand, St. Augustine frequently explains blasphemy against the Holy Ghost to be final impenitence, perseverance till death in mortal sin. This impenitence is against the Holy Ghost, in the sense that it frustrates and is absolutely opposed to the remission of sins, and this remission is appropriated to the Holy Ghost, the mutual love of the Father and the Son. In this view, Jesus, in Matthew 12 and Mark 3 did not really accuse the Pharisees of blaspheming the Holy Ghost, He only warned them against the danger they were in of doing so.
Finally, several Fathers, and after them, many scholastic theologians, apply the expression to all sins directly opposed to that quality which is, by appropriation, the characteristic quality of the Third Divine Person. Charity and goodness are especially attributed to the Holy Ghost, as power is to the Father and wisdom to the Son. Just, then, as they termed sins against the Father those that resulted from frailty, and sins against the Son those that sprang from ignorance, so the sins against the Holy Ghost are those that are committed from downright malice, either by despising or rejecting the inspirations and impulses which, having been stirred in man's soul by the Holy Ghost, would turn him away or deliver him from evil.
It is easy to see how this wide explanation suits all the circuмstances of the case where Christ addresses the words to the Pharisees. These sins are commonly reckoned six: despair, presumption, impenitence or a fixed determination not to repent, obstinacy, resisting the known truth, and envy of another's spiritual welfare.

The sins against the Holy Ghost are said to be unpardonable, but the meaning of this assertion will vary very much according to which of the three explanations given above is accepted. As to final impenitence it is absolute; and this is easily understood, for even God cannot pardon where there is no repentance, and the moment of death is the fatal instant after which no mortal sin is remitted. It was because St. Augustine considered Christ's words to imply absolute unpardonableness that he held the sin against the Holy Ghost to be solely final impenitence. In the other two explanations, according to St. Thomas, the sin against the Holy Ghost is remissable — not absolutely and always, but inasmuch as (considered in itself) it has not the claims and extenuating circuмstance, inclining towards a pardon, that might be alleged in the case of sins of weakness and ignorance. He who, from pure and deliberate malice, refuses to recognize the manifest work of God, or rejects the necessary means of salvation, acts exactly like a sick man who not only refuses all medicine and all food, but who does all in his power to increase his illness, and whose malady becomes incurable, due to his own action. It is true, that in either case, God could, by a miracle, overcome the evil; He could, by His omnipotent intervention, either nullify the natural causes of bodily death, or radically change the will of the stubborn sinner; but such intervention is not in accordance with His ordinary providence; and if he allows the secondary causes to act, if He offers the free human will of ordinary but sufficient grace, who shall seek cause of complaint? In a word, the irremissableness of the sins against the Holy Ghost is exclusively on the part of the sinner, on account of the sinner's act.


Sources
On the dogma see: ST. THOMAS, Summa Theol., I, Q. xxxvi-xliii; FRANZELIN, De Deo Trino (Rome, 1881); C. PESCH, Pælectiones dogmaticæ, II (Freiburg im Br., 1895) POHLE, Lehrbuch der Dogmatik, I (Paderborn, 1902); TANQUEREY, Synop. Theol. dogm. spec., I, II (Rome, 1907-8). Concerning the Scriptural arguments for the dogma: WINSTANLEY, Spirit in the New Testament (Cambridge, 1908); LEMONNYER, Epîtres de S. Paul, I (Paris, 1905). Concerning tradition: PETAVIUS, De Deo Trino in his Dogmata theologica; SCHWANE, Dogmengeschichte, I (Freiburg im Br., 1892); DE REGNON, Etudes théologiques sur la Sainte Trinité (Paris, 1892); TIXERONT, Hist. Des dogmes, I (Paris, 1905); TURMEL, Hist. de la théol. positive (Paris, 1904).

About this page
APA citation. Forget, J. (1910). Holy Ghost. In The Catholic Encyclopedia. New York: Robert Appleton Company. Retrieved July 23, 2010 from New Advent: http://www.newadvent.org/cathen/07409a.htm

MLA citation. Forget, Jacques. "Holy Ghost." The Catholic Encyclopedia. Vol. 7. New York: Robert Appleton Company, 1910. 23 Jul. 2010 <http://www.newadvent.org/cathen/07409a.htm>.

Transcription. This article was transcribed for New Advent by W.S. French, Jr.

Ecclesiastical approbation. Nihil Obstat. June 1, 1910. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York.