If you accept "the fact that property and liberty are concepts invented by humans to bring order and civility to their actions", than you must accept that society has to defend the property and liberty of its citizens. Even if you limit the defence to mental homes for the violently mentally ill and jails for violent robbers. That defence must be paid for - its called tax.
I'm glad you've compromised with reality at last.
A tax may be
one way to defend against violent individuals whether they be mentally ill or robbers. It however isn't the only way, and it certainly isn't the way I would suggest. I'm arguing that there is a better more just and appropo way of handling such issues.
I've got a very short list of compromises I'd remotely consider. Taxing isn't one of them.
But you do agree that mental institutions and jails are needed. Unless you want to have the mentally ill "contract" to pay for their care and the victims of crime forced to pay again for the jail, you need tax.