Thomas makes clear, in full accord with Scripture and Church teaching, that some souls do go straight to heaven or hell. Souls of those who die without any guilt or unpaid debt for even venial sins on their souls will immediately rise to heaven.
All who die in a state of grace, united to God in charity, without mortal sin on their souls, will ultimately attain heaven. Thomas reminds us (expanding on 1 John 5:16-17) that some sins are mortal and some are not mortal, but are merely venial.
The word mortal for mortal sins comes from the Latin word mors for death. Mortal sins produce spiritual death and cut us off from God’s graces, leading to damnation, and not salvation, if we remain unrepentant. In mortal sin we deliberately and selfishly turn away from God in favor of worldly goods. We read in the CCC (1857) that for a sin to be mortal, three things are required: “Mortal sin is a sin whose object is grave matter and which is committed with full knowledge and deliberate consent.” Venial sins (from Latin venia for pardonable) are smaller moral transgressions regarding less serious matters. They do involve an inordinate or inappropriate focus on worldly goods, but do not entail a deliberate turning away from God. They do not cut us off from God’s graces, but “by venial sins man’s affections are clogged so that they are slow in tending toward God” (ST, III, 87, 1).
Thomas says these venial sins are the “wood, hay, stubble” that are cleansed and consumed by the fire of purgatory (1 Cor. 3:12). The punishments of purgatory cleanse us of the debt of punishment for mortal sins that have been confessed and their guilt forgiven, but their punishments not yet satisfied during life. Regarding venial sins, Thomas makes clear that we should never become complacent and uncaring about our venial sins, as a complete complacency and lack of contrition could lead to mortal sin. Still, as for venial sins themselves, the punishments of purgatory can cleanse not only their debt of punishment, but their guilt as well.
We can see this in the case of a person who might die during sleep in a state of grace with no mortal sin on his soul, after having committed some venial sin for which he has not yet experienced contrition. Indeed, in a fascinating hypothetical example (one that perhaps reveals our Angelic Doctor’s penchant for lofty and abstract thought!), Thomas describes the case of a man who commits some venial sin and “has no actual thought of being forgiven or of remedying that sin, but thinks perhaps about a triangle having its three angles equal to right angles, and while engaged in this thought falls asleep and dies.” Thomas declares that such a man would be cleansed form the guilt of his venial sin in the fires of purgatory after death “because punishment so far as it is voluntary, will have the power, by virtue of grace, to expiate such sin as is compatible with grace.”
Those who die unrepentant, with mortal sin on their souls, have willingly rejected God’s love and mercy and chosen to exclude themselves from heaven. Their souls go immediately and irrevocably to hell.
Rise To Heaven
Quite intriguingly, Thomas compares the situation of souls after death to how gravity affects physical bodies. Objects lighter than air will immediately rise, while heavier bodies will immediately fall, unless some obstacle impedes their path. A soul that is freed from all debt of sin will rise immediately to heaven, as a soul mired in mortal sin will descend into hell. An obstacle that can prevent souls free of mortal sin from rising to heaven is the debt of venial sin “for which its flight must needs be delayed, until the soul is first of all cleansed.”
The Catechism teaches that after death we all face an immediate “particular judgment,” in which Christ determines whether our souls will proceed immediately to heaven or hell, or must first undergo a period of purification (1022).
Thomas explains that every person is both an individual person and a member of the whole human race. In the particular judgment we are judged as individual persons. When Christ returns for the Last or General Judgment our souls will be re-united with our bodies and we will all be judged together as members of the human race.
Those who attain heaven will experience unspeakable bliss, as with glowing bodies, they look upon the face of God, the origin and source of every good, upon the glorified body of Christ, and upon a perfected universe.