And it’s really not even that complicated just to understand the basics:
Do eastern Catholics believe in the Immaculate Conception?
To ask that
is to ask the question, “Do eastern Catholics believe that the Blessed Virgin Mary was conceived without the stain of original sin?”
Which is to pose a question to them that uses
exclusively Latin theological terminology. If by “original sin” you mean what
eastern Orthodox Christians believe concerning ancestral sin, then
no, eastern Catholics
don’t believe she was conceived without it -
but by that definition, neither do eastern Orthodox or even Latin Catholics, as Vico explained above.
If by “original sin” you mean what
Latin theology believes concerning ancestral sin, then actually,
some Orthodox Christians believe in the IC, and some do not.
As Bishop Kallistos Ware, a fully canonical Orthodox bishop said:
"From the Orthodox point of view, however, the whole question belongs to the realm of theological opinion; and if an individual Orthodox today felt impelled to believe in the Immaculate Conception, he or she could not be termed a heretic for doing so."
Interestingly enough,
this webpage illustrates just how extensively some eastern Orthodox misunderstand the Immaculate Conception. The interviewer asks of Bishop Kallistos’ statement:
"He seems to be classifying this recently proclaimed roman catholic heretical doctrine as a theologoumena. How could an Orthodox Christian be free to believe in a doctrine which has a direct effect on the doctrine of the Incarnation and the belief in the Dormition of the Mother of God? If the Theotokos was immaculately conceived wouldn’t she be without 'original sin and therefore a higher form of human being and immortal as Adam & Eve were originally created before the fall?"
The answer to these questions is, of course,
no, the IC doesn’t lead to the conclusion that the Theotokos was immortal, as Vico explained above. The assumption that it does reveals just how little many eastern Orthodox understand the dogma.