This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
...temological sloppiness help to obscure the contradictions and to disguise the actual meaning of the doctrine of moral grayness.
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Some people believe that it is merely a restatement
of such bromides as “Nobody is perfect in this world” — i.e., everybody is a mixture of good and evil, and, therefore, morally “gray.” Since the majority of those one meets are likely
to fit that description, people accept it as some sort of natural fact, without further thought. They forget that morality deals only with issues open to man’s choice (i.e., to his free will) ...