What the Church says... of original sin?
The human spirit... suffers difficulty on the part of the senses and the imagination, as well as the evil desires born of the original sin. 

By: Miscellaneous | Source: Published with authorization of www.signodelostiempos.com 

In the historical conditions in which it is found, the man experiences many difficulties to know God with the single light of his reason: 

“The human spirit... suffers difficulty on the part of the senses and the imagination, as well as the evil desires born of the original sin. Hence, in such subjects, men are easily persuaded of falsehood or at least the uncertainty of things that they did not want to be true” (Humani Generis: DS 3875). 

"Man, persuaded by the evil one, abused his freedom, from the beginning of history (GS 13, 1). Succumbed to temptation and committed evil. It retains the desire for good, but its nature carries the wound of original sin. He has been inclined to evil and subject to error” (Catechism of the Catholic Church, 1707). 

"The Lord came in person to liberate and invigorate the man, renovating internally and expelling the prince from this world that held him in the bondage of sin. Sin lowers man, preventing him from achieving his fullness” (Gaudium et Spes 13). 

"A wound in the innermost part of man. We, in the light of faith, call it to sin; beginning with the original sin that each one carries from his birth as an inheritance received from his parents to the sin that each one commits, abusing his freedom” (Reconciliatio et Paenitentia 2). 

"All this harmony of the original justice, envisaged for the man by the design of God, will be lost by the sin of our first fathers" (Catechism of the Catholic Church 379). 

"Sin is present in the history of man: It would be futile to try to ignore it or to give this obscure reality other names. To try to understand what sin is, it is necessary first of all to recognize the deep bond of man with God, because out of this relationship, the evil of sin is not unmasked in its true identity of rejection and opposition to God, even if it continues to weigh On the life of Man and History” (Catechism of the Catholic Church 386).