crucifixion: cross or post?

It seems likely that the upright posts would have already been in position on Golgotha if this was a regular place of execution, and Jesus and Simon of Cyrene would have carried only the patibulum or crossbeam (Matthew 27:32; John 19:17). This means, of course, that Jesus would have been crucified in the conventional Roman manner with his arms outstretched. However, it was not unknown for people to be crucified on a single upright post - in fact bored and barbaric Roman soldiers were inclined to invent all sorts of grotesque variations on the basic method. The argument has been made that this must have been the case with Jesus’ execution because the breaking of the victims legs would have had minimal effect if the arms were attached to a crossbeam. Apparently Jehovah’s Witnesses favour this interpretation. Whether that’s true or not, I’ve no idea.

I can’t see that it really makes a lot of difference from a historical or theological point of view, though obviously our iconography is heavily committed to the traditional form. What is important is the fact that crucifixion represented most acutely the brutality with which the Romans suppressed revolt. What Jesus suffered was what the inhabitants of Jerusalem would suffer 40 years later because of Israel’s ‘sin’, when thousands of Jews were crucified in front of the city walls.

See the Wikipedia article on crucifixion, and James Tabor’s page of excerpts from Josephus.