I brought helpful sections from the Catholic Encyclopedia entries on “Sin” and “Malice.” I thought they would help with the discussion. Note especially what I have in bold in the first section.
On the nature of sin…
In every sin a privation of due order or conformity to the moral law is found, but sin is not a pure, or entire privation of all moral good. There is a twofold privation; one entire which leaves nothing of its opposite, as for instance, darkness which leaves no light; another, not entire, which leaves something of the good to which it is opposed, as for instance, disease which does not entirely destroy the even balance of the bodily functions necessary for health. A pure or entire privation of good could occur in a moral act only on the supposition that the will could incline to evil as such for an object. This is impossible because evil as such is not contained within the scope of the adequate object of the will, which is good.
The sinner’s intention terminates at some object in which there is a participation of God’s goodness, and this object is directly intended by him. The privation of due order, or the deformity, is not directly intended, but is accepted in as much as the sinner’s desire tends to an object in which this want of conformity is involved, so that sin is not a pure privation, but a human act deprived of its due rectitude. From the defect arises the evil of the act, from the fact that it is voluntary, its imputability.
Causes of sin…
The complete and sufficient cause of sin is the will, which is regulated in its actions by the reason, and acted upon by the sensitive appetites. The principal interior causes of sin are ignorance, infirmity or passion, and malice. Ignorance on the part of the reason, infirmity and passion on the part of the sensitive appetite, and malice on the part of the will. A sin is from certain malice when the will sins of its own accord and not under the influence of ignorance or passion.
Imputability of sin…
(*Note that two causes of sin, ignorance and passion, are said to decrease the umputability of sin. That is, ignorance and passion - which can lead to sin - decrease the moral culpability of the person doing the act.)
Error and ignorance in regard to the object or circumstances of the act to be placed, affect the judgment of the intellect and consequently the morality and imputability of the act. Invincible ignorance excuses entirely from sin. Vincible ignorance does not, although it renders the act less free. The passions, while they disturb the judgment of the intellect, more directly affect the will. Antecedent passion increases the intensity of the act, the object is more intensely desired, although less freely, and the disturbance caused by the passions may be so great as to render a free judgment impossible, the agent being for the moment beside himself. Consequent passion, which arises from a command of the will, does not lessen liberty, but is rather a sign of an intense act of volition. Fear, violence, heredity, temperament and pathological states, in so far as they affect free volition, affect the malice and imputability of sin. No mortal sin is committed in a state of invincible ignorance or in a half-conscious state. Actual advertence to the sinfulness of the act is not required, virtual advertence suffices. It is not necessary that the explicit intention to offend God and break His law be present, the full and free consent of the will to an evil act suffices.
More on malice…
The true malice of mortal sin consists in a conscious and voluntary transgression of the eternal law, and implies a contempt of the Divine will, a complete turning away from God, our true last end, and a preferring of some created thing to which we subject ourselves.
When by any conceivable stretch of human wickedness God Himself is the object of hatred the guilt is appallingly special. If it be that kind of enmity which prompts the sinner to loathe God in Himself, to regret the Divine perfections precisely in so far as they belong to God, then the offence committed obtains the undisputed primacy in all the miserable hierarchy of sin. In fact, such an attitude of mind is fairly and adequately described as diabolical; the human will detaches itself immediately from God; in other sins it does so only mediately and by consequence, that is, because of its inordinate use of some creature it is averted from God. To be sure, according to the teaching of St. Thomas and the theologians, any mortal sin carries with it the loss of the habit of supernatural charity, and implies so to speak a sort of virtual and interpretive hatred of God, which, however, is not a separate specific malice to be referred to in confession, but only a circumstance predicable of every grievous sin
Right back at ya 