Reification

Reification: To regard an abstraction or concept as a self-subsistent entity; with Platonic reification an hypostasis of what is in common among particulars into an independent entity standing above them as alone ultimate and real.

Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11.