Success and Failure of Councils

Comparisons between once council and another are dangerous, since one needs to specify in what respect the comparison is being made. If one looks to their practical effectiveness one will find that, for example, Lateran V (1512–1517) achieved nothing regarding the causa reformationis with which it was principally concerned, since its reforming decrees were a dead letter; but that its dogmatic decrees were important since they excluded neoaristotelianism, by condemning those who taught that the sould was mortal. Only a Trent were doctrinal clarification and practical measures equally signficant, but even Trent failed entirely in the causa unionis for which it had primarily been summoned.
— Roman Amerio, Iota Unum: A Study of Changes in the Catholic Church in the XX^th Century, Paragraph 35.