|Eminent Domain is very much justified under an objectivist view of property, as are zoning laws. Without proper governance, when subdivided over the years, lots of land can become balkanized, unmarketable little patches of dirt, not even accessible without trespass onto other property.|
Suppose the following:
Mr. A. owns a 400' x 100' tract of land, with the 100' south side adjacent to a road. Otherwise, the land is surrounded by other property. Mr. A. decides to sell the North 200' feet of the property to Mr. B. A. gives B. a deed, complete with an access easement to the North lot. Because B. is a private person, he doesn't feel the need to record this deed in the local courthouse. A later sells his remaining South lot to Mr. C and moves to Florida. When C. bought A. property, he had no clue of B.'s ownership of the North lot of that he had an access easement to the property across the South lot. C. recorded his deed at the local courthouse. When C. meets B., he decides he doesn't like him, and doesn't give him access into the North lot, regardless of offers and pleas from B. Now B.'s property is landlocked.
Under modern law, this result would not be allowed to happen. A. would be required to get approval from the local zoning board before subdividing his land. B. may have an easement by necessity--C. would have to let him cross over his property regardless of what C. thought. But otherwise, C. would take free of B.'s easement, since he was a bona fide purchaser for value without notice of the deed or easement of the back property. State action is necessary so that almost an acre of land does not become worthless.
An association of businesses and interested citizens in a state desire to build a highway, in order to increase their economic opportunities, livelihood, and movement across the territory. When best mapped geographically, the highway would go across several hundred different parcels of land. Most of these owners approve of these endeavors, but quite a few either don't, or no owner can be located or ascertained. One owner disapproves because of the noise and smell of automobiles. Another disapproves because he believes automobiles are tools of the devil. Another parcel of land has just had its owner die, his heirs and unknown and numerous, his estate is now tied up in probate, and may be for several years. Another parcel of property was owned by a corporation that is no longer active, and none of its former directors can be located. Another parcel just appears to be abandoned, but may not be. Without approval of all these mentioned parties, and others, the highway project would be economically and geographically unfeasible.
The solution: these independent business and free citizens have formed a democratically elected government. That government has the power of eminent domain--to take land for public use. Under this situation, the state would (1) decide the land to take, (2) give just notice to the owners and allow them to appear at a hearing to dispute the public necessity and prove the value of their property, (3) the court would make the just rulings, (4) the state would offer the owners the fair market value of their property, and (5) the state takes possession of the property.
Let me repeat (4) because I think this is commonly forgotten about eminent domain: The state is giving the owners the monetary value of their property. There is no net loss to its owners. The owners can take the money the state gives them and buy another parcel of land.. You could argue that this price would not include "intrinsic" or "sentimental" value of the property. But even if you want consider the subjective, irrational whims of some owners, a court could consider these factors is its valuation and augment what it pays the owners accordingly.
Under modern law, people can't just be allowed "to do whatever they want with their own land." If they did, they could easily wreck marketable title for all their neighbors. Thus zoning and eminent domain law--when not abused--protect property rights, and don't destroy them.