David D. Friedman, in his reply to Matt Zwolinski, says that the solution to the conflict between individual freedom and property rights lies with distinguishing between ownership rights over uncreated property, such as land, and ownership over created property, such as a crop of wheat (or a railroad train):
….You wish to stand on a certain piece of common property. I am there already. You have the same right as I do to stand there, but you do not have a right to move or injure me, hence you cannot exercise your right to stand there without acting unjustly. I have not appropriated the land I am standing on in the usual sense of the term, but I have “de facto” appropriated it for as long as I stand there, not by altering the nature of your right to the land but by making it impractical for you to exercise it without violating other rights.
…..I plant wheat in a field. You come and want to plant wheat in the same field. I point out to you that the field is common property which you are welcome to use, but the wheat I have planted is my property (the result of my labor in gathering seeds, watering them so they would sprout, etc.) and you do not have the right to disturb it. Any way you can figure out to exercise your right to the field without violating my right to the wheat is fine with me.
Taking the last example, a problem arises if one individual plants the entire common area with wheat, preventing anyone else from doing so and causing them to starve. There have to be conventions in the use of common property — which have evolved over time into property rights.