Of course, rights and duties need effective expression though the positive law. As the late Russell Kirk never tired of pointing out, natural law and natural justice are not substitutes for positive law, but rather the predicates upon which positive law depends to function properly to order human community towards order, justice and peace.
The weak spot in Lindsey's argument is that he fails to identify precisely where our rights do come from. If not from the State, then what is their basis? For the Founders, the source of our rights is divine Providence, in the God who creates and sustains the world -- "nature's God" to use a phrase from the Declaration of Independence. At the root of liberty, at the root of limited government, at the root of human freedom, is the truth that prior to and above the State there exists a Power to whom the State itself is subordinate. Take away that truth and the foundation for human rights & limited government collapses in a heap.
Alexander Hamilton, that great American founder whose memory as of late has been under continued assault, understood this well. Writing in The Farmer Refuted in 1775, Hamilton built upon the work of the English jurist William Blackstone to eloquently hold forth on the origin of human rights:
Good and wise men, in all ages, have embraced a very dissimilar theory. They have supposed, that the deity, from the relations, we stand in, to himself and to each other, has constituted an eternal and immutable law, which is, indispensibly, obligatory upon all mankind, prior to any human institution whatever.
This is what is called the law of nature, "which, being coeval with mankind, and dictated by God himself, is, of course, superior in obligation to any other. It is binding over all the globe, in all countries, and at all times. No human laws are of any validity, if contrary to this; and such of them as are valid, derive all their authority, mediately, or immediately, from this original."
Upon this law, depend the natural rights of mankind, the supreme being gave existence to man, together with the means of preserving and beatifying that existence. He endowed him with rational faculties, by the help of which, to discern and pursue such things, as were consistent with his duty and interest, and invested him with an inviolable right to personal liberty, and personal safety.And then in words that stand among the most powerful written during the American revolutionary period, Hamilton thundered:
The sacred rights of mankind are not to be rummaged for, among old parchments, or musty records. They are written, as with a sun beam, in the whole volume of human nature, by the hand of the divinity itself; and can never be erased or obscured by mortal power.The relationship between natural law and human rights has been a well-understood and affirmed part of American law and politics for most of our history, until fairly recent times. Not restricted to the Right, liberals long affirmed this fundamental principle, both in theory and in political rhetoric at the highest levels, as this except from President John F. Kennedy's Inaugural Address shows:
"And yet the same revolutionary beliefs for which our forebears fought are still at issue around the globe -- the belief that the rights of man come not from the generosity of the state, but from the hand of God." Amen to that, Mr. President. Amen to that.