How do we differentiate and integrate concepts?

From Ayn Rand, a champion of reasoning:

“To understand means to focus on the content of a given subject (as against the sensory—visual or auditory—form in which it is communicated), to isolate its essentials, to establish its relationship to the previously known, and to integrate it with the appropriate categories of other subjects. Integration is the essential part of understanding.”

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“Consciousness, as a state of awareness, is not a passive state, but an active process that consists of two essentials: differentiation and integration.”

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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.”

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“[The] enemies of reason seem to know that integration is the psycho-epistemological key to reason . . . and that if reason is to be destroyed, it is man’s integrating capacity that has to be destroyed.?