This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
...refer you to Atlas Shrugged. This present discussion is concerned with the principles by which one identifies and evaluates the instances involving a man’s nonsacrificial help to others.
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“Sacrifice” is the surrender of a greater value for the sake of a lesser one or of a nonvalue. Thus, altruism gauges a man’s virtue by the degree to which he surrenders, renounces
or betrays his values (since help to a stranger or an enemy is regarded as more virtuous, less “selfish,” than help to those one loves). The rational principle of conduct is the exact oppos...