This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
...lism of all hedonist and altruist doctrines lies in the premise that the happiness of one man necessitates the injury of another.
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Today, most people hold this premise as an absolut
e not to be questioned. And when one speaks of man’s right to exist for his own sake, for his own rational self-interest, most people assume automatically that this means his right to sacrific
e others. Such an assumption is a confession of their own belief that to injure, enslave, rob or murder others is in man’s self-interest — which he must selflessly renounce. The idea that ma...