It deals largely with epistemological questions of truth and language, including the formation of concepts. Every word immediately becomes a concept, inasmuch as it is not intended to serve as a reminder of the unique and wholly individualized original experience to which it owes its birth, but must at the same time fit innumerable, more or less similar cases—which means, strictly speaking, never equal—in other words, a lot of unequal cases. Every concept originates through our equating what is unequal. According to Paul F. Glenn, Nietzsche is arguing that "concepts are metaphors which do not correspond to reality." Although all concepts are human inventions (created by common agreement to facilitate ease of communication), human beings forget this fact after inventing them, and come to believe that they are "true" and do correspond to reality. Thus Nietzsche argues that "truth" is actually: A mobile army of metaphors, metonyms, and anthropomorphisms—in short, a sum of human relations which have been enhanced, transposed, and embellished poetically and rhetorically, and which after long use seem firm, canonical, and obligatory to a people: truths are illusions about which one has forgotten that this is what they are; metaphors which are worn out and without sensuous power; coins which have lost their pictures and now matter only as metal, no longer as coins. These ideas about truth and its relation to human language have been particularly influential among postmodern theorists, and "On Truth and Lies in a Nonmoral Sense" is one of the works most responsible for Nietzsche's reputation (albeit a contentious one) as "the godfather of postmodernism."

    He saw in it the rise and climax of values so dear to him that their subsequent drop into catastrophe (in the person of Socrates - Plato) was clearly foreshadowed as though these were events taking place in the theater.And so in this work, unpublished in his own day but written at the same time that his The Birth of Tragedy had so outraged the German professorate as to imperil his own academic career, his most deeply felt task was one of education. He wanted to present the culture of the Greeks as a paradigm to his young German contemporaries who might thus be persuaded to work toward a state of culture of their own; a state where Nietzsche found sorely missing.

    The issues that John Henry Newman raised—the place of religion and moral values in the university setting, the competing claims of liberal and professional education, the character of the academic community, the cultural role of literature, the relation of religion and science--have provoked discussion from Newman's time to our own.