My source is over 60 years of reading such things. You cannot take Cahill's version at face value because it has no practical legal significance.
Fee Simple:
The greatest possible estate in land, wherein the owner has the right to use it, exclusively possess it, commit waste upon it, dispose of it by deed or will, and take its fruits. A fee simple represents absolute ownership of land, and therefore the owner may do whatever he or she chooses with the land. If an owner of a fee simple dies intestate, the land will descend to the heirs.