Focusing on sin in Pelagius as a possibility of exercising freedom and individual responsibility, this paper points out the defense of neutrality, involving the creation of the human being and his capacity for good and evil, emphasizing the freedom of will and its absolute indeterminacy, linking sin to choice. Therefore, by attributing the condition oflocusof the establishment of the existential ethical-logical experience, involving the exercise of freedom, to will, Pelagius opposes the thesis of original sin as a psycho-biological, intellect-affective, and volitional-consciential inheritance transmitted by the human archetype in Adam for his offsprings. Thus, pointing to will as the cause of sin in a movement that converges to end its imputation to the agent as a holder of will in exercise, the text shows that Augustine paradoxically affirms the human tendency to practice evil as a result of Adamic inheritance, which imposes on its posterity the condition of absolute depravity and inescapable guilt, insofar as the human being is constituted as such in a state of holy innocence in a process that attributes to sin the condition of a product of human choice through the exercise of their freedom and full conscience. Finally, the paper examines sin as arational symbol between Pelagius and Augustine, according to Paul Ricoeur, who affirms the need for a process able to deconstruct the concept due to the emergence of the orthodox intention as a straight and ecclesial meaning.