The consciousness of oneness among a people based on a common heritage of traditions and customs, and often also of language.
In its aspirations it centers around national unity and independence.
In these latter times it has, in its spirit, degenerated into jingoism and chauvinism.
As such it is characterized by emotional appeals to a glorious past, a belligerent attitude in foreign relations, a contemptuous disdain of foreigners, a heartless disregard of the rights of minorities, and an arrogant assertion of leadership in the family of nations.
Deifying the nation, it does not recognize the sovereignty of principles of justice.
Nationalism has been called "the great heresy of our times" (Pope Pius XI).
New Catholic Dictionary