>>And the point is that without the concept of private property, there is no liberty.

Right, but Milton did not believe that private property means you can do whatever you like, or that my private property rights trump yours.

The price of living in a society that produces safe loaves of bread for us to buy rather than having to bake our own, and all the other benefits that allow us to specialize, is that none of us has total freedom to do anything we want with our private property whether it be a car or a bakery or a piece of land or whatever. Otherwise your neighbor could build a 20-storey building right on your boundary and too bad for you if it blocks a bit of light, diddums.

Similarly, society can decide that one of the prices of participation is death duties, or that there is a stamp duty you must pay when purchasing property, or that you must pay rates levied according to the value of property. This is fair as long as the taxes are levied universally rather than moochers giving themselves a special deal. E.g. if people are allowed to express property ownership in perpetual trusts or via companies whose shares can be transferred without attracting the tax, then death duties no longer are fair and should be abolished. Otherwise those who don't like it always have the liberty to move to a place without death duties- there are plenty of them. There's even places where your private property rights trump others' if you have more firepower. Plenty of liberty out there for those who want it.