Which of these estates is considered the highest form of ownership?

The highest form of ownership in real property is fee simple absolute. This type of estate provides the owner with complete control over the property without any conditions or limitations. The owner has the right to possess, use, and transfer the property freely and can take full advantage of it for an indefinite period, potentially forever.

In contrast, a life estate grants ownership for the duration of a person's life, meaning that upon their death, the ownership reverts back to another party or remains with the original grantor. Fee simple defeasible, while also a complete ownership, includes conditions that, if violated, can result in the loss of property. A leasehold estate, on the other hand, provides only a temporary right to use and occupy property under specified agreements, lacking the permanence and full control associated with fee simple absolute ownership.

Thus, fee simple absolute stands out as the most robust and unrestricted form of real property ownership.