  A number of elements towards a classification of the quality of emergence in
emergent collective systems are provided. By using those elements, several
classes of emergent systems are exemplified, ranging from simple aggregations
of simple parts up to complex organizations of complex collective systems. In
so doing, the factors likely to play a a significant role in the persistence of
emergence and its opposite are highlighted. From this, new elements for
discussion are identified also considering elements from the System of Leibniz.
