No commentary on the documents of Vatican II nor history of its thinking can dispense with the text of the speeches delivered by the conciliar Fathers in St. Peter's . In these brief addresses, so varied in style and structure, one can discern the development and formulation of doctrine, occasionally by giant strides , but more often by a delicate shading or illumination of familiar ideas heralding new insights that were all but imperceptible at time of the delivery of the speeches.