This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
...m’s life. The physical sensation of pleasure is a signal indicating that the organism is pursuing the right course of action. The physical sensation of pain is a warning signal of danger, indi
cating that the organism is pursuing the wrong course of action, that something is impairing the proper function of its body, which requires action to correct it. The best illustration of this c
an be seen in the rare, freak cases of children who are born without the capacity to experience physical pain; such children do not survive for long; they have no means of discovering what can i...
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