 
 <translate> Consider the question. The concept of original sin was first alluded to in the 2nd century by Irenaeus, Bishop of Lyon in his controversy with certain dualist Gnostics. Other church fathers such as Augustine also developed the doctrine, seeing it as based on the New Testament teaching of Paul the Apostle (Romans 5: 12 -- 21 and 1 Corinthians 15: 22) and the Old Testament verse of Psalms 51: 5. Tertullian, Cyprian, Ambrose and Ambrosiaster considered that humanity shares in Adam's sin, transmitted by human generation. Augustine's formulation of original sin was popular among Protestant reformers, such as Martin Luther and John Calvin, who equated original sin with concupiscence (or "hurtful desire"), affirming that it persisted even after baptism and completely destroyed freedom. The Jansenist movement, which the Catholic Church declared to be heretical, also maintained that original sin destroyed freedom of will.

Answer this question based on the passage: when did the doctrine of original sin begin?
 What is the step-by-step reasoning process to arrive at the answer: the 2nd century? <ibo> Tụlee ajụjụ ahụ. E bu ụzọ zoo aka n'echiche nke mmehie mbụ na narị afọ nke 2 site n'aka Irenaeus, Bishọp nke Lyon n'arụmụka ya na ụfọdụ ndị Gnostic nwere echiche abụọ. Ndị nna ụka ndị ọzọ dịka Augustine mekwara ka ozizi a pụta ìhè, na-ahụ ya dịka nke dabeere na nkuzi Agba Ọhụrụ nke Pọl onyeozi (Ndị Rom 5: 12 - 21 na 1 Ndị Kọrịnt 15: 22) na amaokwu Agba Ochie nke Abụ Ọma 51: 5. Tertullian, Cyprian, Ambrose na Ambrosiaster lere anya na ihe a kpọrọ mmadụ so na mmehie Adam, nke ụmụ mmadụ ketara. Ihe Augustine kwuru banyere mmehie mbụ ahụ na-ewu ewu n'etiti ndị Protestant na-eme mgbanwe, dị ka Martin Luther na John Calvin, bụ́ ndị ji mmehie mbụ tụnyere agụụ mmekọahụ (ma ọ bụ "ọchịchọ na-emerụ ahụ"), na-ekwusi ike na ọ ka dị ọbụna mgbe e mesịrị baptizim ma na-emebi nnwere onwe kpam kpam. Òtù Jansenist, bụ́ nke Chọọchị Katọlik kwuru na ọ bụ ndị jụrụ okwukwe, kwukwara na mmehie mbụ ahụ bibiri nnwere onwe ime nhọrọ.  Zaa ajụjụ a dabere n'akụkụ Akwụkwọ Nsọ a: Olee mgbe ozizi mmehie mbụ ahụ malitere? Gịnị bụ usoro e ji atụgharị uche n'ụzọ kwụ ọtọ iji ruo azịza ya: narị afọ nke abụọ? 