[quote:3k5bzii1]What [i:3k5bzii1][b:3k5bzii1]isn’t[/b:3k5bzii1][/i:3k5bzii1] clear to me is how human nature was before the fall.[/quote:3k5bzii1]

I hope this is helpful:

[color=darkred:3k5bzii1]We believe that in Adam all have sinned, which means that the original offense committed by him caused human nature, common to all men, to fall to a state in which it bears the consequences of that offense, and which is not the state in which it was at first in our first parents established as they were in holiness and justice, and in which man knew neither evil nor death. It is human nature so fallen stripped of the grace that clothed it, injured in its own natural powers and subjected to the dominion of death, that is transmitted to all men, and it is in this sense that every man is born in sin. [/color:3k5bzii1]
Pope Paul VI
The Credo of the People of God
http://www.ewtn.com/library/papaldoc/p6credo.htm

[color=darkred:3k5bzii1]Before the fall, Adam was “innocent” and spiritually alive; his body was meant to be immortal, and he enjoyed a certain “freedom of the soul.” Once he fell, however, he lost these gifts not only for himself but also for his descendants; so that “it was not only the death of the body which is punishment for sin,” but also “sin, the death of the soul, which passed from one man to all the human race.”………………..Before the fall, Adam enjoyed the gift of integrity, which meant absence of the conflict we now experience between our natural urges and the dictates of right reason. After the fall, Adam lost this gift for himself and his posterity, since even those who have been regenerated in baptism are plagued by an interior struggle with their unruly desires and fears..[/color:3k5bzii1]
THE CATHOLIC CATECHISM
Part One: Doctrines of the Faith – III. God, Man, and the Universe
Original Justice and the Fall