This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
... holds that human good does not require human sacrifices and cannot be achieved by the sacrifice of anyone to anyone. It holds that the rational interests of men do not clash — that there is n
o conflict of interests among men who do not desire the unearned, who do not make sacrifices nor accept them, who deal with one another as traders, giving value for value.
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ciple of trade is the only rational ethical principle for all human relationships, personal and social, private and public, spiritual and material. It is the principle of justice.