This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
...trust of reason convulsively seeking to assert its proper function as the pro- tector of one’s life and cognitive integrity.
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Remember that all of man’s knowledge and all his co
ncepts have a hierarchical structure. The foundation and starting point of man’s thinking are his sensory perceptions; on this base, man forms his first concepts, then goes on building the edi
fice of his knowledge by identifying and integrating new concepts on a wider and wider scale. If man’s thinking is to be valid, this process must be guided by logic, “the art of noncontradic...