Integration is a cardinal function of man’s consciousness on all the levels
of his cognitive development. First, his brain brings order into his sensory
chaos by integrating sense data into percepts; this integration is performed
automatically; it requires effort, but no conscious volition. His next step is
the integration of percepts into concepts, as he learns to speak. Thereafter,
his cognitive development consists in integrating concepts into wider and ever
wider concepts, expanding the range of his mind. This stage is fully volitional
and demands an unremitting effort.