A few weeks ago, I noted (citing Galatians 4) that Paul does not observe the common Protestant stricture on drawing doctrinal conclusions from types and allegories. Not surprisingly, the same is true of Thomas.
Thomas answers the question of whether Christ ought to have suffered on the cross (ST III, 46, 4), he answers with a series of analogies and allegories: The cross was suitable because Adam fell at a tree; because being elevated purified the air; because being lifted from the ground gives us a way of ascent to heaven; because the cross has four corners, like the earth that Jesus came to redeem. He cites a sermon of Augustine who said that Jesus’ death on wood was fitting because Noah’s saving ark was wood, because Moses divided the sea and provided water with a wooden staff, because the ark of the covenant was wood, and all these “are like steps by which we mount to the wood of the cross.”
A bit later, when he asks whether Christ’s pain was the greatest of all (III, 46, 6), he answers by citing Lamentations 1:12, the words of which, he says are written “on behalf of Christ’s Person.”
In both cases, allegories of a sort are invoked to solve a doctrinal conundrum.