Dear Brother in Christ,
I am not a theologian but a simple faithful. But I have some historical
notions on the problem.
The sign of the Cross was explained by saint Cyprian as soon as the 3rd
century as a reference to Christ's redemptive death on the cross.
In the Latin rite the sign is made in two ways:
(1) the great sign, made with the five fingers outstretched (symbol of
the five wounds of Christ) on the forehead, breast, and shoulders, left
to right, and
(2) the lesser sign, made with the thumb alone on the forehead, lips,
and breast. This lesser sign was more ancient and is known as the
sphragis, deriving from God's sign in Ezechiel (the ancient form of
the Hebraic letter taw, which was a cross inclined to the right.
Since the 7th century the chalcedonian churches made the great sign with
two fingers (index and middle, symbolic of the two natures in Christ)
but the Monophysite Churches used the index finger alone (symbolic of
the one nature in Christ).
Since the 8th century, chalcedonian churches made the Cross sign with
the five fingers curved, index and middle fingers touching the thumb (a
The Sign is done either left to right (Latin Rite and some Oriental
Churches) or right to left (chalcedonian churches). In the occidental
symbolism, the right is active and the left passive. So the right mean
the future and the left the past.
Another explanation is correlated with the words said : Father (on the
forehead), Son (on the stomach), Holy Spirit (if on the right,
emphasizing the activity of the Holy Spirit, if on the left emphasizing
the Filioque doctrine).
But the most important meaning of the Cross Sign is to set the belonging
The lone certainty is that one finger is monophysite, two fingers
diophysite and three fingers Trinitarian.
I hope some people more learned than me would give us a better answer...
May Christ, our God, keep all of us in His holy guard !