There is a constant stream of books and articles telling us, often strenuously and at great length, that the American Founders got the ideas they used for the Founding from the British philosopher John Locke.  The Founders would be puzzled by this ongoing effort.  They knew different. 

Locke's Two Treatises of Government appeared in 1690.  The articles by Hamilton, Madison, and Jay that became The Federalist began appearing in American newspapers in 1787.  Quite a lot had happened during that intervening century.  The greatest development of all during that time was the onset of the American Enlightenment, that explosion of human genius that gave America and the world the Declaration of Independence, the Constitution, and The Federalist.  The Founders carried out a revolution in thinking about the meaning and possibilities of human life unlike anything the world had ever known before — and by 1776, they were only getting started.  Thomas Jefferson later called The Federalist "the best commentary on the principles of government, which ever was written."  He was right about that.  The distance in thought between Locke's Two Treatises and The Federalist is simply enormous.

Even the Declaration boldly declares its distance from Locke's thinking, though we are told unceasingly that it is a Lockean document.  Those who say the Declaration is Lockean tell us that if we have a question about the Declaration, all we need to do is consult Locke's political philosophy.  Okay, then, here's a question about the Declaration: why "unalienable"?  It is, after all, a somewhat odd word.  It is familiar to us only because it is there in that sentence we all know:

We hold these Truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights[.]

The idea of unalienable rights is in the Declaration because we encounter it everywhere in the writings of the Founders.  Unalienable rights and the Founders' understanding of equality are the core ideas of America's revolutionary mind.  Here's John Adams:

All people are born free and equal, and have certain natural, essential and unalienable rights[.]

Vermont's constitution presents a slight variation on this constantly repeated refrain:

[A]ll men are born equally free and independent, and have certain natural, inherent and unalienable rights[.]

The Founders often used "natural," "essential," and "inherent" in company with "unalienable," but when only one term was used, as in the Declaration, "unalienable" was given pride of place.  Why?

To answer that question, we need to examine "unalienable" in order to understand what it provides that "natural," "essential," and "inherent" do not.  Unalienable, obviously, means not alienable; something that is unalienable cannot be alienated.  But what does it mean to alienate something?  Or rather, what did it mean to the Founders?  Today, we mostly use the term with reference to a breakdown in interpersonal relations.  The first definition in my dictionary is "[t]o cause a person to become unfriendly or indifferent; estrange: alienate a friend."  That is not what the Founders had in mind.  Here is the definition relevant to their meaning: "Law.  To transfer property to the ownership of another."  We alienate property when we sell it, when we give it away, when we leave it to our heirs.  In common speech in the time of the Founders, to alienate was to transfer the title of a property to another person.   Consequently, the Founders' use of "unalienable" had a clear significance that was readily recognized in the Founders' time.

The Founders had a special purpose in using the language of the legal transfer of property in the negative with reference to our rights.  Their special purpose was to make it clear that our natural, essential, and inherent rights are not our property — that is, their special purpose was to make it clear they were not relying on Locke's account of rights. 

In fact, they were doing more; they were evoking a subtle and profound argument that directly challenged Locke's account of rights.  To take you to that argument is to take you to the source of the Founders' use of that special word "unalienable."  Here is Francis Hutcheson in his A System of Moral Philosophy (1755) rejecting Locke's account of our rights: "Our rights are either alienable or unalienable ... our right to our goods and labours is naturally alienable."  Locke, you see, put property at the core of his account:

Man ... hath by nature a power ... to preserve his property — that is, his life, liberty and estate.

For Locke, property is the overarching concept.  In fact, property gets a special emphasis by appearing twice; "estate" is another word for property.  By making the case that our rights to our life and to our liberty are such that we cannot alienate them, Hutcheson was arguing that Locke had not correctly characterized our relation to our lives and our liberty.  Locke had made what philosophers call a category mistake.  Property is alienable; unalienable rights are not property.  It is because our right to our property is alienable that we can sell, exchange, and bequeath our property.

The Founders embraced Hutcheson's argument.  They understood that our rights to life and liberty are natural and inherent to our being as humans.  Our unalienable right to our life and our unalienable right to our liberty cannot rightfully be sold or transferred as property can be.  To say those rights are unalienable is to emphasize how fundamentally different they are from our right to our property — and to reject Locke's account.

To put this in sharp focus, let's put Locke's account and the Declaration side-by-side:

"Man ... hath by nature a power ... to preserve his property — that is, his life, liberty and estate." 

"Men ... are endowed by their Creator with certain unalienable Rights[.] ... [A]mong these are Life, Liberty and the pursuit of Happiness."

Locke's triad is appended to property.  The Declaration's triad is appended to unalienable rights — and property is missing.  These are two fundamentally different accounts.

Locke does deserve credit for getting it all started, but Hutcheson and his followers, especially Thomas Reid, who wrote An Inquiry into the Human Mind on the Principles of Common Sense (1764), and Adam Smith, who wrote The Wealth of Nations (1776), used Locke's thinking as a starting point to make a great leap forward in thought.  The American Founders took it from there. 

Hutcheson and his Scottish colleagues provided the American Founders with many of the ideas that inspired them, but the Founders' work is a new creation.  The Founders thought and built anew.  The world-changing contributions to political thought found in the Declaration and The Federalist Papers, and embodied in the Constitution, are the work of the Founders and the gifts of the American Enlightenment.

Robert Curry serves on the Board of Directors of the Claremont Institute.  He is the author of Common Sense Nation: Unlocking the Forgotten Power of the American Idea.