"We can use observation and logic to arrive at the principle of individual rights..."

"For now, let’s focus on ... [Ayn] Rand’s view of rights. ... Rand based her view for the role of government on the principle of individual rights ...
    "Now, it’s certainly true that rights are not physical things that we can observe. Rights are principles, akin, in that respect, to the principles of physics or biology. Think for a minute of Newton’s first law of motion: A body remains at rest, or in motion at a constant speed in a straight line, unless acted upon by a force. This is a principle—an abstract generalisation about how the world works—derived by observation and logic. No one can look out at the world and see Newton’s first law of motion; nonetheless, everyone can see the evidence that gives rise to it.
    "Rand held that we can likewise use observation and logic to arrive at the principle of individual rights. She pointed out that, unlike other animals, man lives by using his mind. Man must act on his reasoning to create the values on which human life depends. That could be as simple as tracking prey, using dried leaves to start a fire, building a hut, or discerning edible berries from poisonous ones. Or it could be as complex as inventing antibiotics, building a gasoline engine, organizing a multinational supply chain, or providing psychological therapy. To create such values and thus live as human beings, people must be free to think and act on their rational judgment—their basic means of living. The evidence of Rand’s experience—first in Soviet Russia, then in the United States—made this vividly clear. The facts of man’s nature require that he act on his judgment to survive and thrive, and the principle of individual rights identifies this causal relation, just as principles of physics identify causal relations in that field. This is why Rand wrote in 'Atlas Shrugged':

"The source of man’s rights is not divine law or congressional law, but the law of identity. A is A—and Man is Man. Rights are conditions of existence required by man’s nature for his proper survival. If man is to live on earth, it is right for him to use his mind, it is right to act on his own free judgment, it is right to work for his values and to keep the product of his work. If life on earth is his purpose, he has a right to live as a rational being: nature forbids him the irrational. Any group, any gang, any nation that attempts to negate man’s rights, is wrong, which means: is evil, which means: is anti-life."

"This is just an indication of how Rand derived and demonstrated the principle of individual rights. Those interested in learning more should start by reading her essays 'The Objectivist Ethics' and 'Man’s Rights'.”

~ Craig Biddle, from his essay 'Adam Smith, Ayn Rand, and the Philosophic Foundation for Freedom'