This is a quote from the book "The ​Virtue Of Selfishness" by Ayn Rand
...ed for man’s survival qua man.

Since reason is man’s basic means of survival, that which is proper to the life of a rational being is the good; that which negates, opposes or d
estroys it is the evil.

Since everything man needs has to be discovered by his own mind and produced by his own effort, the two essentials of the method of survival proper to a rat
ional being are: thinking and productive work.

If some men do not choose to think, but survive by imitating and repeating, like trained animals, the routine of sounds and motions t...
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