Do they generate proposals with genuine policy import and, importantly, do the five syntheses speak with one voice?
As can be a danger with such large syntheses from multi-organisation meetings, many of the chapters read as fragmentary or overlapping in content.
And this awareness brings us back to the initial question: why are there so many recent syntheses?
It followed that there was a need for syntheses that could enable (still largely absent) comparative urban history.
Such syntheses will have to confront four issues.
While some syntheses were prebiotic and some were not, the compounds synthesized were at least models of the alternative genetic systems.
To date, however, there have been few attempts at comprehensive syntheses of the literature in this topic area.
It thus remains a juxtaposition of brief syntheses of the various regional revolutions rather than a coherent comparison of their social, political and cultural dimensions.