This is a quote from the book "The ​Virtue Of Selfishness" by Ayn Rand, by doing objectively valuable work — indirectly, through the objective evaluation of his work by others.

It is in this sense that a rational man never holds a desire or pursu
es a goal which cannot be achieved by his own effort. He trades value for value. He never seeks or desires the unearned. If he undertakes to achieve a goal that requires the cooperation of many people, he never counts on anything but his own ability to persuade them and their voluntary agreement.

Needless to say, a rational man never distorts or corrupts his own standards...
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