Griffith identified with great clarity at the Sydney Convention perhaps the greatest problem of all: how to structure the relationship between the lower and upper houses within the Federal Parliament. The main division of opinion centred on the contention of Alfred Deakin, that the lower house must be supreme, as opposed to the views of Barton, John Cockburn and others, that a strong Senate with co-ordinate powers was essential. Griffith himself recommended that the doctrine of responsible government should be left open, or substantially modified to accord with the Federal structure.