Hereditary sin

[enitharmon]

What would have happened if not Adam and Eve had sinned, but one of their descendants? Would there have been a Fall for a part of humanity, who would inherit original sin from their sinning ancestors, while another part of humanity, descending from a different descendant of Adam, would have lived unfallen? Or would all humanity inherit the sin of that one individual?

I know such hypothetical scenarios are tricky, but I'm trying to figure out why we suffer the consequences of Adam's sin, and how sin is hereditary? If hereditary original sin is to be thought of as "a state, a permanent privation", and I am born in that state, and "sin is already in the soul" (same source) before we develop the capacity to chose good or evil with the coming of reason, why would God, who creates all of us, fallen?
 

[Basilisa Marie]

Adam and Eve both sinned, but in a lot of poetic rhetoric we talk about Adam's sin. We also talk about how Mary is the new Eve and Jesus is the new Adam, and neither sinned and both cooperated with God (in different ways) to bring about salvation. 

Many theologians also say that sin has consequences not just on humanity, but the whole of creation, the whole cosmos. So it stands to reason that if one person sin everyone and everything would feel the effects. Many Christians used to believe that original sin was something we inherited like genes from our parents, back and back and back. Now some people believe that, but the majority of theologians today seem to think that it's less physical than that, but something we're born with as sons and daughters of humanity. A lot of it depends on how you interpret all of the stories surrounding Adam and Eve. 

I would say it's likely that yes, everyone would be affected by original sin, because it's not strictly genetic. But at the same time it might be no. In the way the story works, God has a covenant with humanity through Adam (as he does with Moses, Abraham, David, etc). The fact that Adam is the one who sinned could be important for the way it all works - if we're talking about original sin vs particular sin, Adam's breach of the covenant with God was his particular sin AND the original sin. If Adam hadn't sinned, would humanity have been spared original sin? Possibly. I think there are good arguments on both sides. 

God allows us to continue in a fallen state because creation, itself, is good, and God loves us, and knew that we could be redeemed through Christ. 

 

It might be helpful to see what the catechism says: http://www.vatican.va/archive/ccc_css/archive/catechism/p1s2c1p7.htm

402 All men are implicated in Adam's sin, as St. Paul affirms: "By one man's disobedience many (that is, all men) were made sinners": "sin came into the world through one man and death through sin, and so death spread to all men because all men sinned." The Apostle contrasts the universality of sin and death with the universality of salvation in Christ. "Then as one man's trespass led to condemnation for all men, so one man's act of righteousness leads to acquittal and life for all men."
 

404 How did the sin of Adam become the sin of all his descendants? The whole human race is in Adam "as one body of one man". By this "unity of the human race" all men are implicated in Adam's sin, as all are implicated in Christ's justice. Still, the transmission of original sin is a mystery that we cannot fully understand. But we do know by Revelation that Adam had received original holiness and justice not for himself alone, but for all human nature. By yielding to the tempter, Adam and Eve committed a personal sin, but this sin affected the human nature that they would then transmit in a fallen state. It is a sin which will be transmitted by propagation to all mankind, that is, by the transmission of a human nature deprived of original holiness and justice. And that is why original sin is called "sin" only in an analogical sense: it is a sin "contracted" and not "committed" - a state and not an act.

405 Although it is proper to each individual, original sin does not have the character of a personal fault in any of Adam's descendants. It is a deprivation of original holiness and justice, but human nature has not been totally corrupted: it is wounded in the natural powers proper to it, subject to ignorance, suffering and the dominion of death, and inclined to sin - an inclination to evil that is called concupiscence". Baptism, by imparting the life of Christ's grace, erases original sin and turns a man back towards God, but the consequences for nature, weakened and inclined to evil, persist in man and summon him to spiritual battle.

406 The Church's teaching on the transmission of original sin was articulated more precisely in the fifth century, especially under the impulse of St. Augustine's reflections against Pelagianism, and in the sixteenth century, in opposition to the Protestant Reformation. Pelagius held that man could, by the natural power of free will and without the necessary help of God's grace, lead a morally good life; he thus reduced the influence of Adam's fault to bad example. The first Protestant reformers, on the contrary, taught that original sin has radically perverted man and destroyed his freedom; they identified the sin inherited by each man with the tendency to evil (concupiscentia), which would be insurmountable. The Church pronounced on the meaning of the data of Revelation on original sin especially at the second Council of Orange (529) and at the Council of Trent (1546).