How does Orthodox Theology reject original sin and not fall into Pelagianism?

One big difference between the Eastern and Western churches is the idea of original sin, Instead of "original sin" the Orthodox Church holds to "ancestral sin" which has been described to me as centering around the idea that nothing God makes is inherently evil. The *OrthodoxWiki* article Original sin says that > "In the Orthodox Church the term ancestral sin (Gr. προπατορικό αμάρτημα) is preferred and is used to define the doctrine of man's 'inclination towards sin, a heritage from the sin of our progenitors' and that this is removed through baptism." The first line of the *Wikipedia* page on Pelagianism states > "Pelagianism is a Christian theological position that holds that the fall did not taint human nature and that humans by divine grace have free will to achieve human perfection." If we are all created good simply with the ability to sin or even a proclivity to sin but are not corrupted by sin then wouldn't it be possible for someone of their own will to not sin? Is that not simply Pelagianism?