Certain unanlienable rights.

And "liberal" is related to "liberty" and "liberation" the converse of which is despotism. Despotism on one scale or another is when one party (even of one) tries to lord it over another. We legitimately get to use force, if necessary, to prevent demonstrable harm to the universal rights of others, not to impose personal or clannish biases.

Who are the outstanding liberators of history and why do we admire them? Why were many of them assassinated?