There is a balance between rights.
One has a right to speak anything they want and a right to feel confident in their reputation. When one person talks about another, these two rights could clash. What is and is not considered libel, as a criminal, serves as an example of how neither right is absolute.
It's typically OK for us to speak and write untrue things; we can even create fiction. However, libel occurs when we write and disseminate false information about another person that harms their reputation. The other person has standing to sue us in court for posting false information intended to harm their reputation because they have a legal right to reputational security.
In general, a crime occurs when two clearly stated rights clash, or when one clearly defined right clashes with what may be called the "generic right" to do anything we want as long as it doesn't hurt anyone. The range of each of our traditional, common law freedoms—the right to be secure in our persons, property, and reputations; the right to free speech; the right to assemble whenever, wherever, and with whomever we choose; the right to keep and bear arms; the right to keep things we find; the right to reclaim things that are ours—is very wide.
There is no way that these rights would never or not frequently come into conflict. Hence, none of them are absolute.
Thank you,
Eddie