Why beat around the bush? Challenge my assertion. Provide a secular basis for human rights.
Human rights are, as you said, social constructs. They are created by the society to fit their needs and values. No god is needed for that.
What exactly are you asking for? Want me to make my own moral system? I don't need to, plenty have done that before me.
Now, imagine this: It may be hard for you, but for the pusrposes of this thought experiment, think of a world with NO magical sky daddy. Somewhere on earth, at some point, some people have gathered to write a bunch of rules for their society. They sign as "the one true magical sky daddy". However, we both know there is no magical sky daddy in this world. Where did they find those rules? Did they pull them out of their ass? No, they set them according to their society's needs and values.
"But there IS a magical sky daddy"
Sure, but these guys are not the only ones making rules. All over the world there have been numerous religions. Do you think their magical sky daddy exists as well? Of course not, because you think yours is the only one. Where did all the others find the rules to govern their societies?
My argument is this:
Just as well as some people can write some rules (an agreement) and pretend they were given to them by some god, some people can write those rules without pretending to be on behalf of any god. The "one true magical sky daddy" signature would just be gone, not the rules themselves.
Challenge my argument. Prove to me that society needs a god to have human rights.