Man is an organism. His function is to live.
Life is conditional. What serves it is good.
To live, he must already be alive, do, and have what he does things for.
These are physical facts. They can only be stopped physically by force initiated by another.
His action is volitional: chosen To do good is right.
Thus it is a right.
Life, liberty, property are his rights.
Life is self-preserving and conditional. To preserve himself by meeting the conditions of his life.
What is, is real. It is what it is. Man knows it.