> When listing man's inalienable rights in the Declaration of Independence, why did
> Jefferson use "pursuit of happiness" instead of "property"?  Isn't it enough to say
> "life, liberty, and property" just as John Locke put it?  In fact, doesn't liberty 
> imply the pursuit of happiness?  


The first part of the Declaration of Independence sets forth inalienable rights in the
form of philosophical principles.  The right to property is not an inalienable right 
that derives from human nature.  It is a right granted by society because it is a
necessary adjunct to our inalienable rights.  No person comes into this world with a
right to a specific piece of property as a part of human nature.  It is difficult to
conceive of a person being born with the right to acquire and hold property, although
that is a right without which life and liberty would have little meaning.  

The pursuit of happiness as an inalienable right encompasses the right to property.  But 
it means much more than just property, just as happiness does not consist merely of
material possessions.  The inalienable right to pursue happiness means that every
individual human being has the right to "be all that he or she can be," not just 
possess all the property that he or she can possess.  Each individual has the right to
realize his or her potential as a human being, always respecting the equal rights of
every other human being.  Inevitably, that includes the right to possess property, 
simply because the denial of that right would severely limit the pursuit of happiness.
Thus, "pursuit of happiness" is a broader and more inclusive term than "property" or 
even "the right to own property."

But it is asked, doesn't the inalienable right to liberty encompass the pursuit of 
happiness, just as the pursuit of happiness encompasses the right to own property?

No, it does not.  Jefferson wrote about liberty,

"Of liberty I would say that, in the whole plenitude of its extent, it is unobstructed 
action according to our will. But rightful liberty is unobstructed action according to 
our will within limits drawn around us by the equal rights of others. I do not add 
'within the limits of the law,' because law is often but the tyrant's will, and always 
so when it violates the right of an individual." --Thomas Jefferson to Isaac H. Tiffany, 
1819. 

Rightful liberty is less than unobstructed action according to our own will.  Rightful
liberty is limited by the equal rights of others.  But what are those equal rights of
others?  Are they just the same life and liberty of ourselves?  Does every individual 
have the right to unobstructed action only limited by the same unobstructed action of
others?  Such a concept expresses no rational limitations, and might vary from person
to person, depending on what kinds of unobstructed actions one wanted to practice and
endure being practiced by others.  That could mean almost anything, and would rest the
definition of limits in each individual, allowing everyone to choose for himself, and 
for others as well.  That could only lead to chaos.  Therefore, something more is
needed.  The pursuit of happiness furnishes that extended principle.  It provides
specificity, whereas liberty has an indefiniteness.  Therefore, pursuit of happiness
is necessary to round-out the meaning and the intention of the right to liberty.