Why is the sign of the Cross of the Orthodox different ?

In the praxis of the orthodox Church, the sign of the cross is made holding three fingers of the right hand together and the other two free: the hand touches firstly the forehead (in the name of the Father), the navel (of the Son) and from the right shoulder (and of the Holy) to the left shoulder (Spirit). Also in the West there was the custom of making the sign of the cross following the orthodox use and of this we have two witnesses: the first is in a bas-relief of the cathedral of Modena (XII century), the second one is provided by Pope Innocent II, who in the De sacro altaris mysterio (book II, c. 45) states: "Signum crucis tibus digitis exprimendum est, ita ut a superiori descendat in inferius et a dextra transeat ad sinistram". In the Catholic world such habit was slowly lost and the gesture of the three fingers together was replaced by the extended hand, while without any specific reason also the movement from the left to the right was inverted, as the same Orthodox pointed out at the end of the XIII century. This progressive change seems to have been started by the same believers in order to then enter definitively into the liturgy with the Reformation of Pope Pius V (XVI century ). The Pope was the last one to abandon the traditional sign of the cross (at least in the disposition of the fingers of the hand), keeping this until some decades ago in his Pontifical blessings.

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