<P> Historian Herbert Thurston interprets this as indicating that at one time both Eastern and Western Christians moved the hand from the right shoulder to the left, although the point is not entirely clear . German theologian, Valentin Thalhofer, thought writings quoted in support of this, such as that of Innocent III, refer to the small cross made upon the forehead or external objects, in which the hand moves naturally from right to left, and not the big cross made from shoulder to shoulder . Andreas Andreopoulos, author of The Sign of the Cross, gives a more detailed description of the development and the symbolism of the placement of the fingers and the direction of the movement . </P> <P> Today, Western Christians and the Oriental Orthodox touch the left shoulder before the right . Eastern Catholics and Orthodox Christians use the right - to - left movement . </P> <P> The proper sequence of tracing the sign of the cross is taught to converts from Christian denominations that are either nontrinitarian or not using the gesture and non-Christian religions . </P> <P> The sign of the cross may be made by individuals upon themselves as a form of prayer and by clergy upon others or objects as an act of blessing . The gesture of blessing is certainly related to the sign of the cross, but the two gestures developed independently after some point . In Eastern Christianity, the two gestures differ significantly . Priests and deacons are allowed to bless using the right hand, while bishops may bless simultaneously with both, the left mirroring the right . While individuals may make it at any time, clergy must make it at specific times (as in liturgies), and it is customary to make it on other occasions . </P>

What is the significance of the sign of the cross