Would you even know you had those rights if someone never told you? No. Because they don't exist.
Ah...I'd like to contest this.
If no one ever told me I had a right to life, yet I would still desire to live. Desiring to live, I would resent and resist any effort to deprive me of that life. In essence, I would be asserting that I had a
right to live when I resisted someone trying to take that from me. This is instinctive in virtually every living creature, and therefore self-evident.
If no one ever told me I had a right to liberty, I would still want to do as I willed, not as others willed for me. I would resent capricious constraints on my liberty, and if possible I would resist them. It is the nature of Man to wish to do as he will, unless his independent spirit has been beaten down into cowering slavishness. That this is natural to human beings is self-evident, imo.
If no one ever told me I had a right to the pursuit of happiness, I would still pursue it, as unhappiness is an unpleasant state of being. Do I need to even go over this one?
Property, the other thing our Founders considered including in that short list, is possibly arguable. The Bantu, if I recall correctly, have little concept of personal property other than one's clothing and one's bow. Of course, they also have almost nothing else BUT those things, so it isn't much of a sacrifice for them. Still when I look at little children arguing "that's MY doll and you can't have it!" I tend to think possession is inborn.
All other rights derive from these.
Now...to pull up some Heinlein from the novel
Starship Troopers, one could argue that a man has no natural rights whatsoever. If I am drowning the sea will not respect my right to life... my liberty can be imposed on in several ways...property too... pursuit of happiness is something that cannot be taken from me but it can be made very difficult. Nonetheless without these three or four things you cannot build a civilization for humans that is remotely just or reasonable, so to consider them "inalienable" is a good basis for building a civilization.
If you wish to believe them a made-up construct, go ahead...but please don't
teach this belief to others. The more people who believe these fundamental rights are
not inalienable, the more likely that someone will try to take them from us.
Some traditions are best left alone... when you pry at the very foundations of your civilization, you are doing so at peril to us all.