Essentialism

Essentialism: A metaphysical theory which maintains that the truth of existing things is an inner principle of determination known only to the mind, not the senses.

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.