What is a "liberal"?

An interesting point is raised at VFR: What makes a liberal a liberal? The one-sentence definition offered there is:

It is the belief that the individual trumps the society and its tradition, even to the point of destroying the society.

That is interesting and certainly true. My own one-sentence definition would be: It is the belief that man is born intrinsically good and that any wrongdoings are not his fault.

Of course, this safely removes the concept of guilt and liability from any wrongdoing, because even "society", the great evildoer, is made up of men who are intrinsically good.